62nd Annual Meeting Austrian Physical Society September 18-21, 2012 University of Graz

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1 F nd 62nd Annual Meeting Austrian Physical Society September 18-21, 2012 University of Graz Karl-Franzens-Universita t Graz ReSoWi-Zentrum, Universita tsstrasse Graz, Austria

2 Impressum Herausgeber Für die ÖPG: Michael Ramsey Karl-Franzens-Universität Graz Institut für Physik Surface- and Interface Physics Universitätsplatz Graz Austria Tel: Fax: michael.ramsey@uni-graz.at Layout Druck M. Wagner, A. Windisch Karl-Franzens-Universität Graz

3 Danksagung / Acknowledgements Die Organisatoren danken für die freundliche Unterstützung von: The organizers wish to thank the support of: Organisation Committee Michael Ramsey Georg Koller Joachim Krenn Leopold Mathelitsch Reinhard Alkofer Falko Netzer 1

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9 Contents 1 Allgemeine Informationen / General information Plenary Sessions HS Energy (AKE): Energietag Mehr Licht! HS Nuclear and Particle Physics (FAKT) Tue: HS 15.02; Thu, Fri: HS Physics Teachers (LHS) HS Acoustics (AKU) LS Atoms, Molecules, Quantum Optics and Plasmas (AMP) LS Solid State Physics (FKP) & Research with Neutron and Synchrotron Radiation (NESY) HS History of Physics (GEP) HS (Physics Building) Medical, Bio and Environmental Physics (MBU) SR Surfaces, Interfaces and Thin Films (OGD) HS Careers in Physics (PIE) HS Posters Contributors Maps

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11 1 Allgemeine Informationen / General information Aktuelle Informationen können von der Website der Konferenz abgerufen werden: Actual information can be downloaded from the conference website: Tagungsort Die Jahrestagung der Österreichischen Physikalischen Gesellschaft findet an der Karl-Franzens-Universität Graz, ReSoWi-Zentrum, Universitätsstrasse 15 C, 8010 Graz, Österreich, statt. Das Tagungsbüro befindet sich für die Dauer der Jahrestagung im Gang C. Den Campus- und Raumplan des ReSoWi-Zentrums finden Sie am Ende dieses Tagungsbandes. Die Theateraufführung Kosmische Strahlen: Das Leben des Victor F. Hess sowie die Sitzung der Arbeitsgruppe GEP (History of Physics) finden im Hörsaal des Physikinstitutes statt. Das UniGraz@Museum befindet sich im Hauptgebäude und ist über den Seiteneingang zu betreten (siehe Campusplan). Vom Hauptbahnhof Graz aus kann die Universität mit den Bussen 63 (Haltestelle Universität ) oder 58 (Haltestelle Mozartgasse ) erreicht werden (Fahrtdauer: Minuten). Die Haltestellen sind im Campusplan eingezeichnet. Des weiteren befinden sich vor dem Hauptbahnhof und vor dem Hauptgebäude der Universität Taxis. Conference venue The Annual Meeting of the Austrian Physical Society is held at the University of Graz, ReSoWi-Zentrum, Universitätsstrasse 15 C, 8010 Graz, Austria. The conference office is situated at the entrance of the ReSoWi building, floor C, for the duration of the conference. A map of the campus and the ReSoWi center is added at the end of this book. The play Kosmische Strahlen: Das Leben des Victor F. Hess as well as the session of the working group GEP (History of Physics) take place in the lecture hall of the physical institute. The UniGraz@Museum is situated in the main building and can be entered via the side entrance indicated in the campus map. At the railway station of Graz ( Hauptbahnhof Graz ) take the bus 63 until to the bus stop Universität or 58 to the stop Mozartgasse (time required: minutes). Bus stops are indicated in the campus map. Moreover, in the front of the railway station as well as in front of the main building of the university are also taxi stands. 9

12 Tagungsgebühren / Conference fees Kategorie Vor 31. Juli Nach 31. Juli Category Before 31 July After 31 July ÖPG Mitglieder, assoz. Mitglieder ÖPG members, assoc. members EURO 70 EURO 80 Mitglieder im Ruhestand ÖPG retired members EURO 35 EURO 40 Nicht-Mitglieder ÖPG non-members EURO 90 EURO 100 Lehrer Teacher EURO 15 EURO 20 Bachelor und Master Studenten Bachelor and Master students frei/free frei/free Doktoranden Ph.D. students EURO 15 EURO 20 Tagesgebühr Daily fee EURO 35 EURO 35 Tagesgebühr Doktoranden Daily fee for Ph.D. students EURO 10 EURO 10 Anmeldung und Zahlungsmodalitäten / Registration and Payment Banküberweisung an / Payments should be made to: Universitaet Graz Bank Austria IBAN: AT BIC: BKAUATWW Verwendungszweck / Reference: OePG A participant s names Bei der Tagesrezeption: Es wird um Bargeld ersucht. Die Anmeldung vor Ort beginnt am Dienstag, 18. September 9:00 16:30, Mittwoch, 19. September 8:30 16:30, Donnerstag, 20. September 8:30 16:30, und Freitag, 21. September 8:30 12:00 (siehe auch Tagungsprogramm). At the conference registration: You are kindly requested to pay in cash at the registration. The registration times are as follows: Tuesday, 18 th September 9:00 16:30, Wednesday, 19 th September 8:30 16:30, Thursday, 20 th September 8:30 16:30, and Friday, 21 st September 8:30 12:00 (see also program). 10

13 Reisekostenzuschuss für studentische ÖPG-Mitglieder Studentische ÖPG-Mitglieder können einen Reisekostenzuschuss mittels des im Tagungsbüro aufliegenden Formulars beantragen (Befürwortung durch Betreuer notwendig). Die Höhe der Zuschüsse richtet sich nach den zur Verfügung stehenden Mitteln, der Zahl der Ansuchen sowie der tatsächlichen Höhe der Reisekosten. Travel support for student members of the ÖPG Student members of ÖPG can apply for travel support via the form available at the registration. The signature (approval) of the applicants tutor is necessary on the form. The amount of support depends of the funds available, the number of applications and the actual travel costs. Unterbringungsmöglichkeiten Unterkünfte in Graz können über oder über Graz Tourismus, Tel , gebucht werden. Accommodation Hotels can be booked via or the Tourist Office Graz, Tel , Hörsäle und Ausstattung Alle Hörsäle sind mit einem PC und einem Beamer ausgestattet, sodass die Mitnahme eines USB-Sticks genügt. Das Betriebssystem ist MS Windows XP mit PowerPoint als Standard-Präsentations-Software. Sollten Sie ein anderes Betriebssystem bzw. eine andere Präsentations-Software benötigen, so ist ein eigenes Notebook mitzubringen. Technische Unterstützung vor Ort ist möglich. Die Erfahrung zeigt, dass es bei den Beamer-Präsentationen immer wieder zu zeitlichen Verzögerungen beim Ablauf der Sitzungen kommen kann (Inkompatibilitäten von Soft- und Hardware, Nicht-Standard-Schriftsätze, etc.). Für einen reibungslosen Ablauf der Fachsitzungen sind die Vorsitzenden der Fachausschüsse verantwortlich. 11

14 Lecture rooms and equipment All lecture rooms are equipped with computer and video projector for which you only need to bring your USB-stick. The operating system is MS Windows XP with PowerPoint as standard presentation software. Should you need another operation system resp. another presentation software it is recommended to supply your own laptop. Technical assistance will be available in the lecture rooms. Experience has proved that there are always delays with preparation of lectures due to incompatibility of software, etc. The chairmen of the topical sessions are responsible for the smooth operation of the session. Poster Format: Breite max. 97 cm, Höhe max. 147 cm, bzw. A0 Format. Posters können bei Beginn der Tagung (Dienstag, 18. Sept. 2012) angebracht werden, und sollten möglichst bis zum Abend des 20. Sept ausgestellt bleiben. Bei der allgemeinen Postersitzung am Mittwoch, 19. Sept. 2012, ab 17:45 Uhr, sollte mindestens ein Autor beim Poster anwesend sein. Der Gewinner des Posterpreises, zur Verfügung gestellt von EPL, wird zu Beginn des Plenarvortrages am Donnerstag um 11:30 bekanntgegeben. Posters Format: Width: 97 cm, height 147 cm (A0 format). You can fix your poster on the first of day of the conference (Tuesday, 18 Sept. 2012). On Wednesday, 19 th Sept. 2012, at 17:45 there should be at least one author presenting the poster at the general poster session. The cash prize for the best poster will be announced on Thursday, at the beginning of the plenary talk at 11:30. 12

15 Buffets und Erfrischungen Das Buffet wird während der Poster Session am Mittwoch von 17:45 20:00 Uhr geöffnet sein. Am Donnerstag, von 18:00 20:00 Uhr, werden im Museum der Karl- Franzens-Universität Erfrischungen zur Verfügung stehen. Buffets and Refreshments During the poster session on Wednesday, 17:45 20:00, food and drinks will be provided. Refreshments will be also provided at the University Museum (Uni- at the end of the Thursday sessions. 13

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17 2 Plenary Sessions HS Tuesday, 18 th September 2012, HS Time Presenter Title 16:30 Opening 17:00 James Cronin (Nobel Laureate) Spontaneous Ionization to Subatomic Physics: Some Vignettes from Cosmic Ray History Wednesday, 19 th September 2012, HS Time Presenter Title 09:00-10:00 John Swain Cosmic Rays: An Ongoing Clear Window into New Physics 10:00-11:00 Franz Gießibl Simultaneous atomic force- and scanning tunneling microscopy a new view on two distinct aspects of the atomic structure of matter 11:20-12:30 Prize Award Session 12:30-13:30 Lunch Break Time Presenter Title 13:30-13:40 13:40-13:50 13:50-14:10 14:10-14:30 Alexander Jesacher Joint Fritz Kohlrausch Prize Daniel Kiener Joint Fritz Kohlrausch Prize Giuseppe Mercurio Max Auwärter Prize Nicolette Doblhoff-Dier Roman Ulrich Sexl Prize Enhancing image contrast in wide-field CARS microscopy by tailored phase matching Advances in understanding small-scale plasticity through in-situ TEM Unfolding Molecule-Metal Interactions using X-ray Standing Waves Physik erfahren, Physik erleben auf vielen Wegen zur Physik 14:30-15:30 Hans Briegel 15:30-16:00 Coffee break Quantum physics, simulation and computation 15

18 Wednesday, 19 th September 2012, HS Time Presenter Title 16:00-16:30 Wolfgang Adam The Higgs Boson search at the LHC - results and perspectives 16:45-17:45 ÖPG General Assembly of Members 17:45-20:00 Poster Session (see chapter Posters) 20:15 Theatre (see page 22), HS 05.01, Physics Building Thursday, 20 th September 2012, HS Time Presenter Title 11:30-12:30 Vahid Sandoghdar On the efficient interaction of single photons and single emitters 16

19 Tue, 17:00-18:00, HS Tue, 17:00, Plenary Spontaneous Ionization to Subatomic Physics: Some Vignettes from Cosmic Ray History James Cronin 1,2 1 The University of Chicago,The Kavli Institute for Cosmological Physics, 933 East 56th Street, Chicago, IL USA 2 Enrico Fermi Institute, University of Chicago, 5640 S. Ellis Avenue, RI-183, Chicago, IL USA In the 1879 Crookes discovered that air seemed to ionize spontaneously. With the discovery in 1896 of radioactivity by Henri Becquerel it appeared that the mystery was solved. However a number of physicists sought a quantitative agreement between the spontaneous ionization and the radioactivity in the earth. The persistence of these physicists led to the discovery of another source of radiation which appeared to come from the heavens. The nature of this cosmic radiation involved phenomena that were completely unknown. Coming to an understanding of the nature of this cosmic radiation took about 40 years between 1912 and This history involves extraordinary scientists and the invention of dramatic new detection techniques. The story finishes with a remarkable conference organized by Patrick Blackett and Louis Leprince-Ringuet 1953 in the Pyrenees town of Bagneres de Bigorre. James Cronin and co-researcher Val Logsdon Fitch were awarded the 1980 Nobel Prize in Physics for a 1964 experiment that proved that certain subatomic reactions do not adhere to fundamental symmetry principles. Specifically, they proved, by examining the decay of kaons, that a reaction run in reverse does not merely retrace the path of the original reaction, which showed that the interactions of subatomic particles are not indifferent to time. Thus the phenomenon of CP violation was discovered. Cronin received the Ernest Orlando Lawrence Award in 1976 for major experimental contributions to particle physics including fundamental work on weak interactions culminating in the discovery of asymmetry under time reversal. He is Professor Emeritus at the University of Chicago and a spokesperson emeritus for the Auger project. The Pierre Auger Observatory, which he proposed, is an international cosmic ray observatory spread over 3000 square kilometers in Argentina, designed to detect ultra-high-energy cosmic rays. Wed, 09:00-10:00, HS Wed, 09:00, Plenary Cosmic Rays: An Ongoing Clear Window into New Physics John Swain 1 1 Northeastern University, Physics Department, 360 Huntington Ave, 111 Dana Research Center, Boston, MA 02115, USA Since Victor Hess s pioneering work in 1912, cosmic rays have provided not only a window into energetic processes in space, but also the first glimpses of many aspects of particle physics. This talk reviews and highlights some of the major achievements in the field, what has been learned, and what major scientific puzzles remain, emphasizing the uniqueness of cosmic rays as a probe of both exotic objects in the far reaches of the universe, and into the deep heart of matter beyond the reach of even modern terrestrial particle accelerators. An outlook for the future is given showing that cosmic ray physics will continue to provide key insights into nature unavailable through any other means. 17

20 Wed, 10:00-11:00, HS Wed, 10:00, Plenary Simultaneous atomic force- and scanning tunneling microscopy a new view on two distinct aspects of the atomic structure of matter Franz Gießibl 1 1 University of Regensburg, Faculty of Natural and Applied Physics II - Physics, Universitätsstrasse 31, D Regensburg, Germany Frequency-modulation AFM can be combined with scanning tunneling microscopy, yielding a simultaneous data set for current and average force gradient. Ternes et al. [1] have shown that for some metallic contacts, force and current are proportional. The figure below [2] shows an example, where combined AFM/STM reveals two strongly distinct aspects of the atomic structure of matter. The gray veil depicts the inverted tunneling current between a CO molecule adsorbed on Cu(111) and a tungsten tip, while the colored surface shows the corresponding force profiles, where the left image corresponds to a W tip oriented in a 100 direction, the right to a 110 direction and the bottom to a 111 direction [3]. While the simultaneous acquisition of current and force can reveal new information about the atomic and electronic structure of matter, the tunneling current can modify the atomic forces. This phantom force [4,5], a modification of the electrostatic attraction between tip and sample, originates in an alteration of the effective potential difference between tip and sample caused by strongly localized voltage drop induced by the tunneling current. The talk discusses the merits of combined STM/AFM as well as the challenges, in particular with respect to tip preparation and characterization. [1] M. Ternes et al., Phys. Rev. Lett. 106, (2011). [2] Created by Joachim Welker (2012). [3] J. Welker, F.J. Giessibl, Science 326, 444 (2012). [4] A.J. Weymouth et al. Phys. Rev. Lett. 106, (2011). [5] T. Wutscher et al. Phys. Rev. B 85, (2012). Wed, 11:00-11:20, Coffee break Wed, 11:20-12:30, HS 15.03, Prize Award Session Fritz Kohlrausch Prize, Victor Franz Hess Prize, Anton Paar Prize, Max Auwärter Prize, Roman Ulrich Sexl Prize, Young Physicists Tournament, Physics Olympiad, Physik-Fachbereichsarbeiten 18

21 Wed, 12:30-13:30, Lunch break Wed, 13:30-14:30, HS 15.03, Prize Winner Talks Wed, 13:30, Joint Fritz Kohlrausch Prize Winner Enhancing image contrast in wide-field CARS microscopy by tailored phase matching Alexander Jesacher 1, Clemens Roider 1, Saranjam Kahn 1, Gregor Thalhammer 1, Stefan Bernet 1, Monika Ritsch-Marte 1 1 Innsbruck Medical University, Division of Biomedical Physics, Müllerstrasse 44, 6020 Innsbruck, Austria Coherent anti Stokes Raman scattering (CARS) is a four-wave mixing process that allows identifying the chemical composition of target substances by recording their molecular vibrational spectra. Combined with microscopy, this technique opens a door to investigating specimens at micrometer scale. A sensitivity limit in CARS microscopy is commonly set by the non-resonant backgrounda parasitic signal component that arises from off-resonantly driven molecular vibrations and/or electronic transitions. In particular for the application of investigating small particles, the non-resonant background generated in the immersion liquid can easily overwhelm the signal of the particles. We introduce a wide-field CARS microscope implementation that allows for effective suppression of the solvent signal by precisely controlling the pump/probe beam incidence angles. Our method relies on the fact that the importance of phase-matching for CARS increases with the size of the target object. Thus, de-tuning these angles by only as much as a degree can lead to a significant loss in the undesired solvent signal while leaving that of the particles almost unaltered. We present experimental results where the ratio of the signals of 500nm polystyrene beads and the surrounding solvent was improved by a factor of about 100. Wed, 13:40, Joint Fritz Kohlrausch Prize Winner Advances in understanding small-scale plasticity through in-situ TEM Daniel Kiener 1 1 Montanuniversität Leoben, Franz-Josef Strasse 18, 8700 Leoben, Austria The uncommon mechanical properties of small volumes, in particular their size-dependent strength and hardening behavior, have received significant interest over the last few years. To exploit these effects for future design of nano-structured materials, it is detrimental to understand the underlying deformation mechanisms that govern the observed sample size effects in micronand sub-micron dimensions. Miniaturized tensile and compression samples were fabricated using a focused ion beam microscope and tested in-situ in a transmission electron microscope. Besides providing precise mechanical data, such highly localized in-situ experiments allow to directly observe the dynamics of crystal defects in real time, and to correlate them to the mechanical signature, thereby delivering valuable insight regarding the governing strengthening mechanisms. It is shown that plastic deformation is governed by the operation of spiral dislocation sources at high stresses. The hardening behavior correlates directly to the exhaustion of such dislocation sources and the ability to create new sources by dislocation interaction. Finally, it is demonstrated that an internal micro-structural length scale smaller than the sub-micron sample size causes a transition from size-dependent to size-independent material properties, allowing to measure bulk properties from nano-scale samples. 19

22 Wed, 13:50, Max Auwärter Prize Winner Unfolding Molecule-Metal Interactions using X-ray Standing Waves Giuseppe Mercurio 1,2 1 Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, Jülich, Germany 2 Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, Jülich, Germany Functional surfaces based on monolayers of organic molecules are currently subject of an intense research effort due to their applications in molecular electronics, sensing and catalysis. Because of the strong dependence of organic-based devices on the local properties of the molecule-metal interface, a direct investigation of the interface chemistry is of paramount importance. In this context, the bonding distance, measured by means of the normal incidence x-ray standing wave technique (NIXSW), provides a direct access to the molecule-metal interactions. At the same time, NIXSW adsorption heights are used to benchmark different density functional theory (DFT) schemes and determine the ones with predictive power to be employed for similar systems. The talk will focus on three molecule-metal interfaces pointing out the physical properties common to other metal-organic systems. The study of a multifunctional organic molecule (perylenetetracarboxylic acid dianhydride, PTCDA) adsorbed on the Ag(110) surface reveals the presence of two distinct bonding channels which depends on the affinity of the respective part of the molecule towards the substrate. The coupling between these bonding channels is probed by means of a local modification of the Ag(110) surface through alkali induced reconstruction. The delicate balance of intermolecular and molecule-substrate interactions for terephthalic acid adsorbed on Cu(100) is investigated by a combined NIXSW-DFT study that suggests the presence of a substrate-mediated interaction, besides the intermolecular H-bonding, as stabilizing force of the molecular islands. Finally, with the aim to better understand the switching properties of photo-active molecules (azobenzene derivatives) adsorbed on metal surfaces, a novel NIXSW analysis scheme, developed to determine the bonding conformation of complex organic molecules adsorbed on single metal crystals with unprecedented accuracy, is presented. Wed, 14:10, Roman Ulrich Sexl Prize Winner Physik erfahren, Physik erleben auf vielen Wegen zur Physik Nicolette Doblhoff-Dier 1 1 AHS-Professorin für Physik, Mathematik und Informatik, Gymnasium Maria-Regina, 1190 Wien Physik im Unterricht soll Interesse, ja sogar Begeisterung hervorrufen, Neugier wecken, genaues Beobachten lehren, logisches Denken fördern, zum Nachdenken und Fragen anregen, Diskussionen vom Zaun brechen und Begreifen ermöglichen. Physik im Unterricht soll neue Welten eröffnen, Zusammenhänge zeigen und Brücken schlagen. SchülerInnen wollen in ihren Interessen angesprochen werden und erkennen, dass Physik überall ist, in der Geschichte, Kunst und Religion (Projekt Physik im Stephansdom ), in der Musik und Mathematik ( Was macht das Klavier wohltemperiert? ), in der Medizin ( Hochenergie und Med-Austron ), ja sogar beim Vereinbaren von Terminen ( Von Sonnenuhren über die gregorianische Kalenderreform bis zur Atomuhr ). Einen Schwerpunkt des Vortrags bildet das Projekt Die vielen Gesichter des Sir Isaac Newton, in Kooperation mit der Österreichischen Akademie der Wissenschaften, im Rahmen dessen zahlreiche wissenschaftliche Plakate entstanden, sowie fiktive Zeitungsartikel, Fernsehdiskussionen und Rätsel, die das Leben von Newton aus unterschiedlichen Blickwinkeln betrachten. Die SchülerInnen schauten staunend durch die gebastelten Fernrohre und Mikroskope und diskutierten heftig über die von ihnen übersetzten Originaltexte von Isaac Newton aus dem Trinity-College und Voltaires Buch Les elémens de la philosophie de Neuton. Ich möchte zeigen wie wichtig es ist, den SchülerInnen viele unterschiedliche Wege zur Physik zu ermöglichen. Ich möchte sie lehren zu fragen und zu staunen! 20

23 Wed, 14:30-15:30, HS Wed, 14:30, Plenary Quantum physics, simulation, and computation Hans Briegel 1 1 Universität Innsbruck, Institut für Theoretische Physik, Technikerstrasse 25, 6020 Innsbruck, Austria The ultimate scope and power of computers will be determined by the laws of physics. Quantum computers exploit the rules of quantum mechanics, using quantum coherence and entanglement for new ways of information processing. Up to date, the realization of these systems requires extremely precise control of matter on the atomic scale and a nearly perfect isolation from the environment. The question, to what extent quantum information processing can also be exploited in natural and less controlled systems, including biological ones, is exciting but still open. In this talk, I will present some of our recent work on (quantum) physically and biologically motivated models of information processing. Wed, 16:00-16:45, HS Wed, 16:00, Plenary The Higgs Boson search at the LHC - results and perspectives Wolfgang Adam 1 1 Austrian Academy of Sciences, Nikolsdorfergasse 18, 1050 Vienna, Austria Two experiments have recently announced the discovery of a new boson with a mass near 125 GeV at the CERN LHC. This new particle matches the expectations for the Higgs boson, the missing piece of the Standard Model of particle physics, which has been one of the main targets of experiments in the last decades. This talk will give details on the experimental evidence, focussing on results of the Compact Muon Solenoid (CMS) experiment. First measurements of the properties of the new particle will be compared to the expectations of the Standard Model. The fundamental implications of the existence of a Higgs boson for particle physics will be explained. The plans for further measurements of the properties of this boson and the implications for discovery of Physics beyond the Standard Model will be discussed. 21

24 Wed, 20:15, HS (Physics Building) Wed, 20:15, HS (Physics Building), Theatre Play Kosmische Strahlen - Das Leben des Victor F. Hess Klaus Reitberger 1, Stadttheater Kufstein Insights into the eventful life and scientific struggle of Victor F. Hess are presented in this one-hour play. Based on historic accounts and personal letters, the unique character of the much acclaimed scientist is portrayed through several key episodes of his life. From the famous balloonflight in 1912 to the research at the Hafelekar-observatory high above Innsbruck, from receiving the Nobel prize in physics to the dramatic escape from Nazi-Germany on the eve of World War II. Written and directed by a physicist and performed by actors of the Stadttheater Kufstein [1], this project attempts to let history and science meet on stage. The play has already been performed in Vienna, Innsbruck and Kufstein. Further performance are foreseen in Pöllau, Siegen, Berlin and Hamburg. A six-minute video-trailer of the play can be viewed on [2]. The play will be performed in German. An English translation will soon be published by University Press Innsbruck. The German script is already available. [1] strahlen.php [2] embedded&v=4 8Udh2HoW8. 22

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26 Thu, 11:30-12:30, HS Thu, 11:30, Plenary On the efficient interaction of single photons and single emitters Vahid Sandoghdar 1 1 Max-Planck Institut, Günther-Scharowsky-Strasse 1 / Bau 24, Erlangen, Germany In the 1990s, many pioneering experiments demonstrated the potential of single organic molecules embedded in solids as quantum mechanical two-level systems. However, coherent interactions were not studied because those experiments relied on recording the fluorescence signal, which only accesses populations of the excited state and not the coherences. Recently, we showed theoretically that in the linear excitation regime, an atom can block a propagating light beam by up to 100% if it is confined to an area comparable with its scattering cross section [1]. I will present an overview of our recent experimental work on the efficient interaction of light and single organic molecules both in the near and far fields [2, 3]. We will see that at T<2K, a single molecule can attenuate [2, 3], transmit, amplify [4] or phase-shift [5] a focused laser beam. Furthermore, I will report on the first direct long-distance communication of two optical emitters via single photons [6]. I will then discuss strategies for the optimization of the interaction between single photons and single emitters via, e.g. ultra-high collection efficiency [7, 8] or enhancement of spontaneous emission [9] by using plasmonic and dielectric antennas. [1] G. Zumofen, et al., Phys. Rev. Lett. 101, (2008). [2] I. Gerhardt, et al., Phys. Rev. Lett. 98, (2007). [3] G. Wrigge, et al., Nature Phys. 4, 60 (2008). [4] J. Hwang, et al., Nature 460, 76 (2009). [5] M. Pototschnig, et al. Phys. Rev. Lett. 107, (2011). [6] Y. Rezus, et al., Phys. Rev. Lett. 108, (2012). [7] K-G. Lee, et al., Nature Photonics 5, 166 (2011). [8] X-W. Chen, S. Götzinger, V. Sandoghdar, Opt. Lett. 36, 3545 (2011). [9] X-W. Chen, M. Agio, V. Sandoghdar, Phys. Rev. Lett. 108, (2012). 24

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29 3 Energy (AKE): Energietag Mehr Licht! HS AKE: Norbert Pillmayr, Tuesday, 18 th September 2012, HS Time Presenter Title 10:00-10:15 Norbert Pillmayr Mehr Licht! Das Vorwort zum Energietag :15-10:45 Helmut Tributsch Bio-analoge Energie- und Materialwirtschaft 10:45-11:15 Robin Hirschl Strom für die Welt und wie uns die Sonne dabei helfen kann 11:15-11:45 Thomas Posch Bedarfsgerecht und energieeffizient beleuchten 11:45-12:15 Johann Gerstmann Das kann Sonnenschutz: Energie, Licht und Wärme zum Nulltarif! 12:15-12:45 Günther Leising Leuchtdioden verändern unsere Welt 12:45-13:30 Lunch 13:30-13:50 HAK/HAS Mistelbach Oma Glühbirne, Enkerl LED und der wilde Onkel Scheinwerfer erzählen 13:50-14:20 Dieter Parth LED Die Lichtquelle der Zukunft revolutioniert auch die Automobilindustrie! PHOTO-TEKTUR: Qualitativer 14:20-14:50 Gregor Radinger Lichteintrag und photobiologische Grundlagen für ArchitektInnen 14:50-15:20 Wilfried Pohl Licht und Energie im Gebäude 15:20-15:50 Mathias Schaffer Smart Lighting for Smart Citizens Mehr Licht!? und innovative Beleuchtungskonzepte für Smart Cities 15:50-16:00 Norbert Pillmayr Schlussworte Tue, 10:00-12:45, HS

30 Tue, 10:00 Mehr Licht! - Das Vorwort zum Energietag 2012 Norbert Pillmayr 1 1 KELAG - Kärntner Elektrizitäts-Aktiengesellschaft, Klagenfurt, Austria Nach den Energietagen 2010 in Salzburg (Thema: Realisierung der Klimaziele) und 2011 in Wien mit dem Schwerpunkt Energie effizient nutzen ist 2012 in Graz die oftmals unterschätzte Thematik der Lichtenergie das Hauptthema des Energietags. Licht macht ca. 20% des weltweiten und 14% des europäischen Stromverbrauchs aus. Diverse Innovationen in der Lichttechnik können bei der Erreichung der Kyoto-Ziele helfen, da Kosten gespart, die Umwelt geschützt und die Beleuchtungsqualität verbessert werden. Licht kommt eine wesentliche Bedeutung für Komfort, Emotion, Motivation und Leistungsbereitschaft zu. In gewerblich genutzten Gebäuden wie Produktions-, Verkaufs- und Bürogebäuden entfallen zwischen 30% und 40% auf Energiekosten. Hier können durch eine effiziente Lichtgestaltung Energieeinsparungen erzielt und somit Betriebskosten gesenkt werden. Energieeffiziente Beleuchtung leistet damit einen wesentlichen Beitrag zur Erreichung der Klimaziele. Die Umwelt wird durch verringerten Energieverbrauch und einer Reduktion der Kohlendioxydbelastung geschont, Kosten werden gesenkt und die Lichtqualität für das Wohl des Menschen wird gleichzeitig verbessert. Der Arbeitskreis (AK) Energie ist ein sehr aktiver Arbeitskreis in der Österreichischen Physikalischen Gesellschaft (ÖPG), der Interessensvertretung der Physiker in Österreich. Ein dreiköpfiger Vorstand vertritt gleichberechtigt Wissenschaft, Industrie und Lehre. Zentrales Thema des AK Energie ist die Behandlung der physikalischen Aspekte und Perspektiven von Energiefragen unter besonderer Berücksichtigung der österreichischen Situation. Diese sollen in Zusammenarbeit mit Vertretern aller relevanten Fachrichtungen diskutiert werden. Es wird vor allem Konsens in der Einschätzung der naturwissenschaftlich technologischen Aspekte der Energieproblematik angestrebt. Tue, 10:15 Bio-analoge Energie- und Materialwirtschaft Helmut Tributsch 1,2 1 Freie Universität Berlin, Takustraße 3, Berlin, Germany 2 Helmholtz-Zentrum Berlin für Materialien und Energie Kekuléstrasse 5, Berlin, Germany Die Menschheit hätte eine reelle Chance, durch massive Forschung, über eine solar betriebene Energie-Wirtschaft, längerfristig ins Gleichgewicht mit der Natur zurück zu finden. Das von der Natur vorgegebene und über Hunderte von Jahrmillionen Jahren bewährte Vorbild beinhaltet die Spaltung von Wasser mit Licht und die Anhaftung des freigesetzten Wasserstoffs an einen Kohlenstoff-Träger, Kohlendioxid, zur Bereitstellung von Energieträgern und Baustoffen. Die Umsetzung dieser Produkte durch die Pflanzen- und Tierwelt führt zu geschlossenen, nachhaltigen Energie-Stoff-Kreisläufen. Sie wird wirksam unterstützt durch eine Reihe bisher von unserer Technik nicht beherrschte beziehungsweise nicht erschlossenen Technologien. Sie reichen von kinetisch funktionierenden Solarzellen, zu photo-katalytischer Wasserspaltung, Kohlendioxid-Fixierung, zu effektiver Energie-Katalyse und tensiler Wasser-Technologie. Es wird analysiert, wie die Menschheit sich diesen von der Natur realisierten Zielen mit zunächst vereinfachten Techniken schrittweise annähern könnte. Angelpunkt wäre anfangs die massive Bereitstellung von billigem Wasserstoff, der dann mit vergaster Biomasse zu nachhaltigen Brenn- und Rohstoffen verbunden werden könnte. Die gegenwärtige Brennstoff-Infrastruktur bliebe im Wesentlichen erhalten. Der Einstieg in diese Natur-nahe Strategie besteht darin, die Quellen höchster nachhaltiger Energiedichte, die stürmischen Meere, für die Wasserstoff-Gewinnung zu nutzen. Dies wäre über eine Unter-Wasser- Technologie denkbar, bei der nur die sich mit den Wellen bewegenden, energiewandelnden Bojen an die Wasseroberfläche reichen. Diese Wasserstoff- Technologie sollte in zwei bis drei Jahrzehnten realisierbar sein. Weitere nötige und nützliche Technologien in Richtung einer bio-analogen, globalen Energiewirtschaft könnten innerhalb dieses Jahrhunderts verfügbar sein. Die Herausforderungen und Vorteile werden diskutiert. 28

31 Tue, 10:45 Strom für die Welt und wie uns die Sonne dabei helfen kann Robin Hirschl 1 1 ENcome Energy Performance GmbH, Klagenfurt, Austria Die Sonne: Ein gigantischer Kernfusionsreaktor, 150 Millionen Kilometer von der Erde entfernt. Und trotz der Entfernung liefert dieser Reaktor jährlich mehr als das fache des weltweiten Bedarfs an Primärenergie. Im Vortrag sollen zunächst die verschiedenen Möglichkeiten solare Energie zu nutzen diskutiert werden. Anschließend wird auf die physikalischen und wirtschaftlichen Details der Photovoltaik näher eingegangen. Sowohl der derzeitige Stand der Technik als auch die theoretischen Grenzen der Technologie werden beschrieben. In weiterer Folge soll mit einigen Vorurteilen rund um die Photovoltaik aufgeräumt werden, wie zum Beispiel dass die Photovoltaik bei der Erzeugung mehr Energie verbraucht als während der Lebensdauer der Anlagen produziert wird, oder dass die Photovoltaik nicht ohne Subventionen wirtschaftlich sein kann. Im zweiten Teil werden, ausgehend von den derzeitigen technischen und ökonomischen Auswirkungen der Implementierung von PV Anlagen in europäische Stromnetze, die Möglichkeiten und Herausforderungen von signifikanten PV Kapazitäten im Netzverbund behandelt. Insbesondere mangelt es noch an einer effizienten und langzeitstabilen Möglichkeit zur Energiespeicherung, um Photovoltaik in lokalen autarken Netzen exklusiv einsetzen zu können. Andererseits können größere Gruppierungen von PV Anlagen schon jetzt dazu beitragen, einige der technischen Schwierigkeiten heutiger Verteil- und Übertragungsnetze zu meistern. Abschließend soll ein Blick in die Zukunft helfen zu verstehen, welche Möglichkeiten realistisch in der Solarenergie stecken und in welchem Kontext eine echte Energiewende hin zu erneuerbaren Energien tatsächlich möglich erscheint. Tue, 11:15 Bedarfsgerecht und energieeffizient beleuchten Thomas Posch 1 1 Universität Wien, Universitätsring 1, 1010 Wien, Austria Künstliche Beleuchtung macht unser Leben (scheinbar) leichter: die Gestaltung unserer Arbeitsund Freizeit wird flexibler, sogenannte Angsträume verschwinden, Produktionsvorgänge können - auch ohne Mitternachtssonne - 24 Stunden und 7 Tage pro Woche aufrecht erhalten werden. Erst in den letzten Jahren hat sich durch wissenschaftliche Untersuchungen gezeigt, dass künstliches Licht nicht immer und in jeder Menge dem Menschen und der Natur gut tut. Chronobiologen, Entomologen, Ornithologen, aber auch Lichttechniker fanden heraus, dass künstliche Beleuchtung mit Maß und Ziel eingesetzt werden sollte - im Innen- wie im Außenraum. Das Glühlampenverbot der EU rückte Licht als bedeutenden Faktor im Energiekonsum in unser Bewusstsein (wenn auch auf unglückliche Weise!). Der Vortrag zeigt, dass und wie Beleuchtung nicht nach dem Gießkannenprinzip, sondern bedarfsgerecht erfolgen sollte. Es wird auch darauf aufmerksam gemacht, dass Energieeffizienz alleine nicht zu umfassend besserem Licht führt. Grundlage der Ausführungen ist das Buch Das Ende der Nacht Die globale Lichtverschmutzung und ihre Folgen von Thomas Posch, Anja Freyhoff, Thomas Uhlmann (Hg.) Wiley-VCH Verlag, Weinheim

32 Tue, 11:45 Das kann Sonnenschutz: Energie, Licht und Wärme - zum Nulltarif! Johann Gerstmann 1 1 Bundesverband Sonnenschutztechnik Österreich, Guntramsdorf, Austria Um solare Energie richtig nutzen zu können, muss die Kraft der Sonne je nach Tages- und Jahreszeit sowie entsprechend bautechnischer Parameter wie Raumnutzung, Bauweise, Glasqualität, Fensterflächen-anteil, Orientierung der Fassaden, bedarfsgerecht geregelt werden. So wie ein Thermostatventile die Heizung regelt, so sollte temporärer und intelligent gesteuerter Sonnenschutz den Wärmeeintrag über Fenster und Glasfassaden regeln. Im Gegensatz zur Notwendigkeit den Energieeintrag dem Außenklima anzupassen, gilt es diffuses Tageslicht maximal zu nutzen für eine hohe Tageslichtautonomie im Sinne der Energieeffizienz aber vor allem in Hinblick darauf, dass die Wirkung von Tageslicht auf den Menschen durch Kunstlicht nicht ersetzt werden kann. Vor Sonne schützen aber gleichzeitig Tageslicht nützen muss kein Widerspruch sein, ist aber eine spannende Herausforderung sowohl für die Architektur als auch für die Industrie! Sonnenschutz ist eine passive Technologie um thermischen und visuellen Komfort in Gebäuden bei geringstem Energiebedarf zu sichern. Neben Photovoltaik und Solarthermie ist die Sonnenschutztechnik - also das Managen des Energie- und Lichteintrages über transparente Flächen die dritte aber inoffizielle Säule solarer Energienutzung, die zum Erreichen der EU Ziele noch eine große Rolle spielen kann. Tue, 12:15 Leuchtdioden verändern unsere Welt Günther Leising 1 1 Technische Universität Graz, Petersgasse 16/1.Sotck, 8010 Graz, Austria Wir sehen mit unseren Augen Licht im Bereich von violett (400 nm) bis rot (750 nm). Da jeder Mensch ein individuelles Lichtempfinden hat, wurde für den technischen Vergleich ein Normauge festgelegt, das bei 555 nm (grün) die maximale Sehempfindlichkeit hat. Damit wir alle Farben eines Objekts tatsächlich wahrnehmen können, muss die Lichtquelle mit der es beleuchtet wird, Licht aller Farben im Bereich des Sichtbaren aussenden. Nur die Glühbirne (und die Halogenlampe) hatten bisher annähernd diese Eigenschaft. LED sind kleine (typisch 0.3x0.3 mm), dünn-schichtweise aufgebaute Festkörper-Lichtquellen die mit Spannungen einiger Volt betrieben werden. Mit einer blauen, grünen und roten LED oder mit einer blauen LED und neuartigen Farbstoffumhüllungen kann praktisch Licht aller Farben und auch weißes Licht mit hoher Farbwiedergabequalität erzeugt werden. Wichtige Eigenschaften neben der Farbwiedergabe einer Lichtquelle sind die Effizienz (Lumen/Watt) und die Farbtemperatur in Kelvin (K). Eine Glühbirne hat eine Effizienz von 10 bis 15 lm/w und je nach Betrieb Farbtemperaturen zwischen 2700K und 6500K. Die Effizienz einer Halogenlampe liegt bei 20 lm/watt. Energiesparlampen und Leuchtstoffröhren haben typischerweise um die 80 lm/w. Gute weisse LEDs liegen derzeit zwischen 70 und 100 Lumen/Watt und das erreichbare Ziel für LEDs liegt bei 200 Lumen/Watt. Die anvisierte Lebensdauer von LED Lichtquellen liegt weit über Stunden. Mit der LED Technologie erlebt die Lichttechnik und damit die Beleuchtung eine längst fällige Erneuerung und Bereicherung. 30

33 Tue, 12:45-13:30: Lunch Tue, 13:30-16:00, HS Tue, 13:30 Oma Glühbirne, Enkerl LED und der wilde Onkel Scheinwerfer erzählen Mistelbach HAK/HAS 1 1 HAK/HAS Mistelbach, Brennerweg 8, 2130 Mistelbach, Austria Vorstellung und Diskussion (Film der HAK/HAS Mistelbach) Tue, 13:50 LED Die Lichtquelle der Zukunft revolutioniert auch die Automobilindustrie! Dieter Parth 1 1 Infineon Technologies Austria AG, Application Specialist Power LED Drivers, Villach, Austria Die Verwendung von LEDs ist heute einer der Designtrends im Automobilbereich, um den Wiedererkennungswert unterschiedlicher Automarken zu steigern. Mittlerweile sind jedoch die Leuchtstärken der LEDs so hoch, dass auch Auf- und Abblendlichter und damit komplette Voll- LED Scheinwerfer Lösungen realisiert werden können. Der LED Trend beschränkt sich nicht nur auf die Fahrzeugaußenbeleuchtung. Im Fahrzeuginnenraum wird durch die Verwendung von RGB LEDs eine individuelle Anpassung der Innenbeleuchtung möglich. Aufgrund der kleinen Baugröße, der geringen Stoßempfindlichkeit sowie hohen Effizienzen werden völlig neuartige LED-Lichtdesigns möglich. Die Lebensdauer von LEDs ( Stunden) ist bei richtiger Handhabung um ein Vielfaches höher als bei gewöhnlichen Glühlampen (1000 Stunden). Gerade bei Heckleuchten profitiert man vom schnellen Ansprechverhalten der LEDs, welche beim Anzeigen des Bremsvorganges einen Sicherheitsvorteil bieten. Intelligente Halbleiterlösungen zur Ansteuerungen von Glüh- oder Halogenlampen haben bereits lange Tradition beim Villacher Chiphersteller Infineon - er ist seit Jahren Marktführer auf diesem Gebiet. Die Infineon AUTO LED Familie beinhaltet Produkte zur Ansteuerung von LED Licht-Funktionen. Deren Hauptaufgaben sind die genaue Regelung des zur Funktion benötigten Laststromes, die Diagnose und der Schutz der Lasten vor Übertemperatur und Boardnetzschwankungen. Dass sich der LED Trend auch im Automobil voll durchsetzt zeigen bereits zahllose Beispiele auf unseren Straßen. Laut Experten soll es im Jahr 2030 bereits keine Glühbirnen mehr im Auto geben. Infineon trägt maßgeblich zur Entwicklung und Markteinführung von LED-Beleuchtungslösungen im Automobil bei. 31

34 Tue, 14:20 PHOTO-TEKTUR: Qualitativer Lichteintrag und photobiologische Grundlagen für ArchitektInnen Gregor Radinger 1 1 Donau-Universität Krems, Department für Bauen und Umwelt, Dr.-Karl-Dorrek-Straße 30, 3500 Krems, Austria Hintergrund: Beim Durchgang durch Verglasungen werden wesentliche Bereiche des solaren Strahlungs-spektrums ausgefiltert. Natürliches Licht, das derart spektral ausgedünnt den Innenraum erreicht, ist aus humanphysiologischer Sicht reduziert oder gar nicht wirksam. Vor diesem Hintergrund werden tatsächliche Gegebenheiten der Tageslichtversorgung in Innenräumen, mit Focus auf den ultravioletten und sichtbaren Spektralbereich aufgezeigt. Planungsrelevanz: Aufbauend auf diesen Erkenntnissen werden Empfehlungen für photobiologisch notwendige Eigenschaften von transparenten Bauteilen und gesundheitsförderlicher Raumkonfigurationen erstellt. Darüber hinaus wird die Bedeutung direkter und diffuser Lichteinträge auf die qualitative Wahrnehmung von Räumen untersucht, um den wichtigen Stellenwert von Licht für die allgemeine Akzeptanz von Architektur zu unterstreichen. Vortragsthemen: Strahlungsangebot im Außenraum Strahlungsangebot im Innenraum Visuelle und nicht visuelle Lichtwahrnehmung Qualitative Raumwahrnehmung bei diffusem und direktem Lichteintrag Ableitungen für architektonische Entwurfsstrategien Tue, 14:50 Licht und Energie im Gebäude Wilfried Pohl 1 1 Bartenbach LichtLabor GmbH, Aldrans, Austria Im Vortrag wird die Rolle des Lichtes für den Energiehaushalt eines Gebäudes erläutert. Dabei spielt nicht nur die elektrische Beleuchtung sondern insbesondere auch die Tagesbelichtung eine wichtige Rolle. Es wird ein Überblick und Ausblick über energiesparende Beleuchtungstechnologien gegeben und der Zusammenhang mit visuellem Komfort und dem Wohlbefinden erläutert. Die Richtlinie 2010/31/EU des europäischen Parlaments und des Rates vom 19. Mai 2010 über die Gesamtenergieeffizienz von Gebäuden besagt, dass neue Gebäude ab 2021 als Niedrigstenergiegebäude errichtet werden sollen. In diesem Zusammenhang spielt der elektrische Energieverbrauch für Beleuchtung eine zunehmend wichtigere Rolle. Der Vortragende ist als Prokurist bei der Fa. Bartenbach LichtLabor in Aldrans für Forschung zuständig. Er ist in zahlreiche internationale Energieforschungsprojekte involviert, u.a. hat er im Auftrag des BMVIT Österreich im internationalen IEA- Projekt Energy efficient electric Lighting for Buildings vertreten und die Arbeitsgruppe Zukünftige Lichttechnologien geleitet (die Internationale Energieagentur IEA ist eine zwischenstaatliche Einrichtung zur Förderung energiesparender Technologien und Aktivitäten), sowie im EU-Projekt Commoncense (Comfort monitoring for CEN standard EN15251 linked to EPBD) die österreichische Beteiligung geleitet (ein Projekt der Intelligent Energy Europe, kurz IEE). Hier wird u.a. die Rolle der Beleuchtung (Kunst- und Tageslicht) für den Energieverbrauch von Gebäuden untersucht. 32

35 Tue, 15:20 Smart Lighting for Smart Citizens - Mehr Licht!? und innovative Beleuchtungskonzepte für Smart Cities. Mathias Schaffer 1 1 Energie Steiermark, Graz, Austria Die Energie Steiermark beschäftigt sich seit 2010 systematisch mit dem Thema Innovation bzw. Innovationsmanagement. Zielsetzung der Innovation ist dabei primär die Entwicklung neuer Ideen zu marktfähigen Produkten und Energie-Dienstleistungen im Kontext zum beginnenden Wandel der Energiesysteme sowie des gesellschaftlichen Wertewandels. Neben der aktuellen, kundenorientierten Entwicklung von innovativen Produkten und Dienstleistungen u.a. auch für den Bereich der Beleuchtung werden die Haupt-Innovationsthemen der Branche wie z.b. Smart Meter/Grid, dezentrale Erzeugung und Elektromobilität als Teil großflächiger Modellversuche sog. Smart Cities demonstriert. Energie und deren Verwendung bzw. Anwendung unter Einsatz neuester und hocheffizienter Technologie ist auch in der Stadt der Zukunft ein Schlüsselthema wie leben und arbeiten wir im Jahr 2050, welche Energieformen und Technologien stehen uns zur Verfügung? Eine (mögliche) Projektion der Vision 2050 einer Smart City für das Thema Licht... Tue, 15:50 Schlussworte Norbert Pillmayr 1 1 KELAG - Kärntner Elektrizitäts-Aktiengesellschaft, Klagenfurt, Austria 33

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37 4 Nuclear and Particle Physics (FAKT) Tue: HS 15.02; Thu, Fri: HS Nuclear and Particle Physics Kern- und Teilchenphysik Daniel Grumiller, Tuesday, 18 th September 2012, HS :30-16:00 Time Presenter Title 13:30-13:50 Tobias Jenke Gravity Resonance Spectroscopy within the qbounce experiments 13:50-14:10 Johann Marton New experiments on light kaonic atoms 14:10-14:22 Barbara Wünschek Comparison of the yields in kaonic helium-3 and helium-4 14:22-14:34 Clemens Sauerzopf Measuring the hyperfine-splitting of Antihydrogen 14:34-14:46 Martin Diermaier An apparatus for the production of a mono atomic hydrogen beam AMS Measurements of Supernova- 14:46-14:58 Jenny Feige Produced Radionuclides in Deep-Sea Sediment Cores 14:58-15:10 Edith Schmidt AMS detection of 10Be with a silicon nitride foil stack: higher efficiency, lower background 15:10-15:22 Jakob Liebl The age of olfactory bulb neurons in humans: an application of dating microgram DNA samples with the C14 bomb peak 35

38 Thursday, 20 th September 2012, HS :00-11:00 Time Presenter Title 09:00-09:20 Wolfgang Adam Recent results from the CMS experiment at the LHC 09:20-09:32 Wolfgang Waltenberger The CMS simplified models results interpreted for your favorite theory a how-to Search for Supersymmetry in final 09:32-09:44 Robert Schöfbeck states with b-jets and leptons with the CMS experiment 09:44-09:56 Ilse Krätschmer Measurement of Upsilon(nS) Polarization with CMS 09:56-10:08 Patrick Jussel Recent Heavy Flavour Results at the ATLAS Experiment at the LHC 10:08-10:20 Anna Usanova Search for rare Bs µ + µ decay with the ATLAS detector 10:20-10:32 Wolfgang Lukas Measurement of charged-particle multiplicities with the ATLAS detector at the LHC 10:32-10:52 Christoph Schwanda Physics at the Belle II experiment 10:52-11:04 Felicitas Thorne Study of B0s J/ψK + K decays at Belle experiment 11:04-11:30 Coffee break Thursday, 20 th September 2012, HS :30-15:30 Time Presenter Title Holographic dilepton and prompt photon 14:30-14:42 Stefan Stricker production in a thermalizing plasma 14:42-14:54 Richard Williams Status of the g-2 of the muon: trouble for the standard model or theorists overconfidence 14:54-15:06 Christian Kohlfürst Electron-Positron Pair Production in Structured Pulses of Electric Fields Zwei- und Dreipunktfunktionen zweidimensionaler 15:06-15:18 Markus Huber Yang-Mills-Theorie in Landau Eichung 15:18-15:30 Tina Herbst Polyakov-Loops and the QCD Phase Structure 15:30-15:50 Coffee break 36

39 Thursday, 20 th September 2012, HS :50-18:00 Time Presenter Title 15:50-16:02 Mario Mitter Consequences of an Infrared Divergent Quark 4-Point Function 16:02-16:14 Valentin Mader Renormalization in Functional Approaches 16:14-16:26 Andreas Windisch What is (not) a Glueball? 16:26-16:38 Markus Hopfer The Role of the Quark-Gluon Vertex Function in the QCD Phase Transition 16:38-16:58 Reinhard Alkofer Properties of the Delta and Omega Baryons from QCD Bound State Equations 16:58-17:10 Matthias Blatnik The sigma meson in a covariant Dyson- Schwinger - Bethe-Salpeter approach 17:10-17:22 Gernot Eichmann Nucleon Compton scattering in the Dyson-Schwinger approach 17:22-17:34 Harold Steinacker Matrix Models as unified models of fundamental interactions Friday, 21 st September 2012, HS :00-11:00 Time Presenter Title 09:00-09:12 Thomas Wieninger Producing a new in-house C-14 standard by irradiating graphite 09:12-09:24 Josef Buchriegler A multi-anode ionisation chamber for AMS at VERA 09:24-09:44 Gertrud Konrad Status Report on PERC Ein Neutronenspinresonator zur 09:44-09:56 Christoph Gösselsberger Erzeugung Wellenlängen-selektierter Neutronenpulse 09:56-10:08 Xiangzun Wang Magnetic Field System of PERC 10:08-10:20 Florian Teischinger Calibration of the ATLAS electromagnetic calorimeter at the per mill level 10:20-10:32 Elmar Ritsch The Integrated Simulation Framework A novel Detector Simulation Approach in the ATLAS Experiment 10:32-10:44 Bernhard Lutzer Radiation-hard silicon sensors for the CMS tracker upgrade 10:44-10:56 Edwin Frühwirth Development and Production of Silicon Particle Detectors in Austria 11:00-11:30 Coffee break 37

40 Friday, 21 st September 2012, HS :30-13:30 Time Presenter Title 11:30-11:42 Wolfgang Treberer-Treberspurg Monitoring of the radiation induced effects of the CMS Tracker 11:42-11:54 Immanuel Gfall Belle II Silicon Vertex Detector: Mechanics 11:54-12:06 Annekathrin Frankenberger Belle II Silicon Vertex Detector: Cooling 12:06-12:18 Jakob Lettenbichler Low-momentum track reconstruction in the vertex detector of Belle II 12:18-12:30 Winfried Mitaroff Forward Tracking in a Linear Collider Detector 12:30-12:42 Sebastian Frank Computational Uncertainties in Public BR(B X sγ) Codes 12:42-12:54 Lukas Gruber Recovery Time and Double Hit Resolution Measurements of SiPMs Using a Double Pulsed Laser 38

41 Tue, 13:30-16:00, HS Tue, 13:30 Gravity Resonance Spectroscopy within the qbounce experiments Tobias Jenke 1 1 Technische Universität Wien, Stadionallee 2, 1020 Wien, Austria Newton s Inverse Square Law of Gravity may be tested at micron distances deeply into the theoretically interesting regime by quantum interference with ultra-cold neutrons. Our newly developed method is based on a resonance spectroscopy technique related to Rabi spectroscopy, which has been adapted to gravitationally bound quantum systems: By coupling such a quantum system to mechanical vibrations, we observe resonant transitions, devoid of electromagnetic interaction. As Newtonian gravity and hypothetical Fifth Forces evolve with different phase information, the experiment has the potential to test the equivalence principle and Newton s gravity law at the micron scale. This experiment can therefore test speculations on large extra dimensions of submillimetre size of space-time or the origin of the cosmological constant in the universe, where effects are predicted in the interesting range of this experiment and might give a signal in an improved setup. Tue, 13:50 New experiments on light kaonic atoms Johann Marton 1, The LEANNIS network 2, The SIDDHARTA Collaboration 3 1 Österreichische Akademie der Wissenschaften, Boltzmanngasse 3, 1090 Vienna, Austria The antikaon interaction on nucleons and nuclei in the low-energy regime is neither simple nor well understood. Even the kaonic hydrogen and kaonic deuterium cases are complicated due to sub-threshold resonances most prominent is the Lambda(1405) resonance of still heavily debated nature. New experimental studies via x-ray spectroscopy of the lightest kaonic atomic systems (kaonic hydrogen and helium isotopes) have successfully performed by the SIDDHARTA Collaboration at LNF (Frascati, Italy) recently. Consequently new precision data on the strong interaction observables were delivered giving important impact for the theory. The talk will give an overview of the progress and present status of experimental studies and will provide an outlook to future perspectives in this fascinating research field. 39

42 Tue, 14:10 Comparison of the yields in kaonic helium-3 and helium-4 Barbara Wünschek 1, Tomoichi Ishiwatari 1, Eberhard Widmann 1, Johann Zmeskal 1, Michael Cargnelli 1, Johann Marton 1 1 Österreichische Akademie der Wissenschaften, Boltzmanngasse 3, 1090 Vienna, Austria Kaonic helium is an exotic atom where a kaon replaces a shell electron, well suited for the study of the strong interaction at low energies. The strong interaction between the kaon and the nucleus affects the low-lying atomic states in the kaonic helium atom by causing a shift compared to its purely electromagnetic value. This shift can be measured with spectroscopic tools, which was recently performed by the SIDDHARTA experiment. Via a measurement of the X-ray transitions to the 2p level, the X-ray transitions in kaonic helium-3 and helium-4 (at different densities) were measured with a complex SDD detector system. With the data set of these measurements, the X-ray yields (i.e. the net production of characteristic X-rays) of the kaonic helium gases have been determined for the first time. The absolute yields were obtained with inputs from a Monte Carlo simulation. Since the previous measurements on the kaonic helium X-ray transitions solely used liquid helium targets, these results give crucial information on theoretical calculations of the densitydependence of the yields. The evaluation procedure and the results are going to be presented in detail. Tue, 14:22 Measuring the hyperfine-splitting of Antihydrogen Clemens Sauerzopf 1, Martin Diermaier 1, Silke Federmann 1, Chloé Malbrunot 1, Oswald Massiczek 1, Barbara Wünschek 1, Johann Zmeskal 1, Eberhard Widmann 1, The ASACUSA Collaboration 2 1 Österreichische Akademie der Wissenschaften, Boltzmanngasse 3, 1090 Vienna, Austria 2 In our current understanding of the standard model of particle physics, the CPT (charge, parity, time) symmetry states that the laws of physics do not change under inversion. The ASACUSA Collaboration intends to test this fundamental property of the model by measuring a hyperfine transition in Antihydrogen, the antimatter pendant to ordinary matter Hydrogen, using a Rabi like experimental setup. Compared to the number of cosmic particles and background radiation from Antiproton annihilation a proper Antihydrogen event is quite rare. To accomplish a good measurement we need a fine discrimination between proper events and background hits. To this purpose, our counting system consists of a veto detector to single out upstream annihilations, a central segmented detector, and a hodoscope which provides a good detection probability for decay pions. In this talk I will discuss the development of the Antihydrogen counter and present first preliminary results of measurements at the CERN Antiproton Decelerator (AD). 40

43 Tue, 14:34 An apparatus for the production of a mono atomic hydrogen beam Martin Diermaier 1, Oswald Massiczek 1, Eberhard Widmann 1, Johann Zmeskal 1 1 Österreichische Akademie der Wissenschaften, Boltzmanngasse 3, 1090 Vienna, Austria CPT (charge, parity, time) symmetry plays a fundamental role in our understanding of physical laws under the simultaneous inversion of charge, parity and time the physics law do not change. The CPT symmetry will be tested by the ASACUSA collaboration at the CERN facility. This test will be done in a Rabi like experiment with antihydrogen atoms, the antimatter pendant to normal hydrogen atoms. Since the creation of antihydrogen atoms is very complicated the whole setup has to be tested and calibrated with hydrogen. Therefore an atomic hydrogen beam apparatus has been setup, using a microwave discharge source for the production and a quadrupole mass spectrometer for the detection of the mono atomic hydrogen beam. In this talk the apparatus and first test measurements will be discussed. Tue, 14:46 AMS Measurements of Supernova-Produced Radionuclides in Deep-Sea Sediment Cores Jenny Feige 1, Anton Wallner 2, Stephan Winkler 1, Silke Merchel 3, Keith Fifield 2, Gunther Korschinek 4, Georg Rugel 3, Robin Golser 1 1 University of Vienna, Währinger Strasse 17, 1090 Vienna, Austria 2 Australian National University,Building No. 57, The Australian National University, Canberra, ACT 0200, Australia 3 Helmholtz Institute Freiberg for Resource Technology, Halsbrücker Straße 34, Freiberg, Germany 4 Technische Universität München, James-Franck-Str. 1, Garching, Germany Accelerator Mass Spectrometry (AMS) provides the highest sensitivity for measurements of long-lived radionuclides with half-lifes in the order of million years. We apply this method to search for live supernova (SN)-produced radionuclides on Earth. An indication to recent SN activity in our solar neighborhood is the existence of a thin, hot cavity in the local interstellar medium, embedding our solar system. This so called superbubble, the Local Bubble, was produced by multiple SN explosions, starting 14 Myr ago. Nuclides, which are synthesized in massive stars and during their explosions, are then entrained in the SN shell and may be transported to the solar system and thus into Earth archives, if such an event happens within a short distance. Two deep-sea sediment cores originating from the Indian Ocean have been selected to search for the SN-produced radionuclides 26Al, 53Mn, 60Fe and 244Pu in the time range of 2-3 Myr. We aim to measure these isotopes at different laboratories with high time resolution with the goal to confirm a previously found SN signal in a ferromanganese crust from the Pacific Ocean. 41

44 Tue, 14:58 AMS detection of 10Be with a silicon nitride foil stack: higher efficiency, lower background Edith Schmidt 1, Peter Steier 1, Josef Buchriegler 1, Jenny Feige 1, Martin Martschini 1, Leonard Michlmayer 1, Alfred Priller 1, Anton Wallner 1, Eva-Maria Wild 1, Robin Golser 1 1 University of Vienna, Währinger Strasse 17, 1090 Vienna, Austria 10Be, with a half-life of 1.39 Ma, is a long-lived, naturally occurring radioisotope with versatile applications. It is a cosmogenic nuclide, produced in the atmosphere and in-situ in surface rocks. 10Be therefore carries valuable signals for climate research [1,2] and also is the primary tool for exposure dating [3] in geology. Accelerator Mass Spectrometry (AMS) with its outstanding abundance sensitivity is the only technique capable of measuring 10Be at natural levels and separating it from abundant isobaric 10B. Based on extremely homogeneous silicon nitride foils, we have developed a new AMS-method to detect 10Be at the Vienna Environmental Research Accelerator (VERA). The new method has a significantly higher overall efficiency, provides superior precision and is simpler to implement. For comparison, we also present the two other methods, which are available at VERA and commonly used at other facilities: absorption of 10B in a gas cell, and the use of a degrader foil followed by a magnetic separator. [1] RAISBECK et. al. (2006) 10Be evidence for the Matuyama-Brunhes geomagnetic reversal in the EPICA Dome C ice core. Nature 444, 82. [2] WILLENBRING, J.K., VON BLANCKENBURG, F. (2010) Long-term stability of global erosion rates and weathering during late-cenozoic cooling. Nature 465, 211. [3] JOHN, C., GOSSE, F., PHILLIPS, M.(2001) Terrestrial in situ cosmogenic nuclides: theory and application. Quaternary Science Reviews 20, Tue, 15:10 The age of olfactory bulb neurons in humans: an application of dating microgram DNA samples with the C14 bomb peak Jakob Liebl 1,2,3, Peter Steier 1, Olaf Bergmann 4, Jonas Frisén 4, Kirsty Spalding 4, Robin Golser 1, Klaus Mair 1, Alfred Priller 1, Eva-Maria Wild 1, Walter Kutschera 1 1 University of Vienna, Währinger Strasse 17, 1090 Vienna, Austria 2 MedAustron, Viktor Kaplan-Straße 2, 2700 Wiener Neustadt, Austria 3 Medizinische Universität Graz, Auenbruggerplatz 32, 8036 Graz, Austria 4 Karolinska Institutet, SE Stockholm, Sweden The determination of C14 levels in genomic DNA can be used to retrospectively establish the birth date of cells in the human body which was pioneered at the Karolinska Institute. Aboveground nuclear weapons testing between 1950 and 1963 doubled the atmospheric C14 content. After the Partial Nuclear Test Ban Treaty in 1963 the excess C14 decreased again by exchange of carbon dioxide between atmosphere, biosphere and the ocean. As a consequence all humans who lived in the second half of the 20th century have been labelled with this rapidly changing excess C14. During the last years the amount of carbon required for a C14 Accelerator Mass Spectrometry (AMS) measurement at the VERA Laboratory in Vienna was reduced to such an extent (mg to µg) that investigations of neurons of particularly interesting small sections of the human brain became possible. C14 measurements of < 5µg carbon DNA samples with an overall precision of 2.0 to 2.5% were achieved. This allowed to study neurogenesis in the human olfactory bulb [1], which turned out to take place primarily at birth with <1% of these neurons being exchanged at a later time. This identifies a fundamental difference in the plasticity of the human brain compared to other mammals. [1] O. Bergmann, J. Liebl, S. Bernard, K. Alkass, M.S.Y. Yeung, P. Steier, W. Kutschera, L. Johnson, M. Landén, H. Druid, K.L. Spalding, J. Frisén, The Age of Olfactory Bulb Neurons in Humans, Neuron 74, 634 (2012) 42

45 Thu, 09:00-11:00, HS Thu, 09:00 Recent results from the CMS experiment at the LHC Wolfgang Adam 1 1 Institut für Hochenergiephysik, Nikolsdorfer Gasse 18, 1050 Wien, Austria The CMS experiment is in its third full year of data taking at the LHC, recording proton-proton collisions at a record centre-of-mass energy of 8 TeV. The total integrated luminosity is expected to clearly exceed the 5 fb 1 available for the analysis of 2011 data. CMS pursues a wide research programme with highlights ranging from the search for the Higgs boson and supersymmetric particles to precision measurements in top- and b-quark physics. An overview of the most significant CMS results with emphasis on those obtained from the first part of 2012 data will be presented. Thu, 09:20 The CMS simplified models results interpreted for your favorite theory a how-to Wolfgang Waltenberger 1 1 Institut für Hochenergiephysik, Nikolsdorfer Gasse 18, 1050 Wien, Austria The year 2011 was a fruitful one for the CMS teams that searched for physics beyond the standard model. The results of many analyses have been interpreted in the context of simplified models, i.e. effective Lagrangians which introduce only a minimal set of hypothetical, new particles. In this talk, a description and summary of these simplified models results will be given. An application of these results that can be performed by physicists outside the CMS collaboration will be presented. Thu, 09:32 Search for Supersymmetry in final states with b-jets and leptons with the CMS experiment Robert Schöfbeck 1 1 Austrian Academy of Sciences, Nikolsdorfer Gasse 18, 1050 Vienna, Austria A large class of supersymmetric models predict an enhanced production of 3rd generation fermions at the LHC. In particular, the supersymmetric partners of bottom and top quarks could be among the lightest charged supersymmetric particles and would give rise to jets originating from the fragmentation of b-quarks. Results from searches for Supersymmetry with the CMS experiment using final states including with b-jets are reported based on proton-proton collision data at a centre-of-mass energy of 7 TeV and 8TeV. In particular, a searches for events with (b-)jets, isolated leptons and high missing transverse energy are presented. The results are also interpreted in the framework of simplified models. 43

46 Thu, 09:44 Measurement of Upsilon(nS) Polarization with CMS Ilse Krätschmer 1 1 Austrian Academy of Sciences, Nikolsdorfer Gasse 18, 1050 Vienna, Austria An introduction to the measurements of quarkonia polarization with the CMS detector at the LHC is presented. The measurement is based on the angular distributions of decays into muons. The polarization parameters λ θ, λ φ and λ θφ as well as a frame invariant quantity λ are determined. This frame-invariant quantity provides an intrinsic test of the reliability of the whole analysis chain and gives supplementary physical information. Results for the Y(1S), Y(2S) and Y(3S) mesons using data collected in 2012 are shown. Thu, 09:56 Recent Heavy Flavour Results at the ATLAS Experiment at the LHC Patrick Jussel 1 1 University of Innsbruck, Technikerstrasse 15, 6020 Innsbruck, Austria In 2011 data corresponding to an integrated luminosity of more than 5 fb 1 has been collected by the ATLAS experiment [1] at the Large Hadron Collider at CERN. The heavy flavour program covers the measurement of CP violation, the discovery of new B hadrons and very rare B meson decays. In this presentation recent results of the ATLAS heavy flavour physics program will be presented. [1] The ATLAS Collaboration; The ATLAS Experiment at the CERN Large Hadron Collider; JINST 3 (2008) S08003 Thu, 10:08 Search for rare Bs µ + µ decay with the ATLAS detector Anna Usanova 1 1 University of Innsbruck, Technikerstraße 15, 6020 Innsbruck, Austria A blind analysis searching for the decay Bs µ + µ has been performed [1] using protonproton collisions at a centre-of-mass energy of 7 TeV recorded with the ATLAS detector at the LHC in The Bs µ+µ branching fraction is measured with respect to the reference decay B± J/ψK±. The details of this analysis and the most recent results on the measurement of the branching fraction BR(Bs µ + µ ) will be presented. [1] The ATLAS Collaboration; Search for the decay B0s µ + µ with the ATLAS detector; to be published 44

47 Thu, 10:20 Measurement of charged-particle multiplicities with the ATLAS detector at the LHC Wolfgang Lukas 1, Emmerich Kneringer 1, Andreas Salzburger 2 1 University of Innsbruck, Technikerstraße 15, 6020 Innsbruck, Austria 2 CERN, 1211 Geneva 23, Switzerland Measurements of charged-particle distributions in particle collider experiments provide an essential insight into the understanding of soft QCD as well as high-pt phenomena, which are becoming increasingly important for high-energy physics at the LHC. The status of ongoing measurements of the charged-particle multiplicity in proton-proton interactions at the center-of-mass energy s = 8 TeV, depending on transverse momentum and pseudorapidity, and of the relationship between mean transverse momentum and charged-particle multiplicity, is presented for the ATLAS experiment. These measurements are compared to Monte Carlo models, particularly the Pythia6 and Pythia8 tunes. Finally the 8 TeV results are combined with previous measurements from 900 GeV to 7 TeV, in order to validate and improve the extrapolation of the central chargedparticle multiplicity per event and unit of pseudorapidity for tracks with transverse momentum pt > 100 MeV and pt > 500 MeV. Thu, 10:32 Physics at the Belle II experiment Christoph Schwanda 1 1 Austrian Academy of Sciences, Nikolsdorfer Gasse 18, 1050 Vienna, Austria The B factory at KEK in Japan is being upgraded to become a Super B factory: The new experiment, Belle II, will start data taking in the year 2015 and aims at increasing the B factory dataset by two orders of magnitude. This huge luminosity will allow to study B and tau decays with unprecedented precision and gain sensitivity to physics scenarios beyond the Standard Model of particle physics (so-called New Physics). We will present the planned measurements and give expected sensitivities in key observables. We will explain how different New Physics models can be probed with the upgraded detector. Thu, 10:52 Study of B0s J/ψK + K decays at Belle experiment Felicitas Thorne 1, Christoph Schwanda 1 1 Austrian Academy of Sciences, Nikolsdorfer Gasse 18, 1050 Vienna, Austria The Belle experiment in Tsukuba (Japan) has collected a unique 121/fb dataset near the Y(5S) resonance, which allows to study B0s meson decays. We will report a study of B0s J/ψK + K decays using this sample. This includes the measurement of the absolute branching fractions for B0s J/ψφ with φ K + K and B0s J/ψK + K, the search for the decay B0s J/ψf 2(1525) with f 2(1525) K + K and the determination of the s-wave contribution in the φ mass range. The decay B0s J/ψφ is an important mode for measuring the CP violating phase β s, which is particularly sensitive to physics beyond the Standard Model. This work is supported by the Austrian Science Fund (Grant Nr. P22742-N16). 45

48 Thu, 14:30-15:30, HS Thu, 14:30 Holographic dilepton and prompt photon production in a thermalizing plasma Stefan Stricker 1 1 Vienna University of Technology, Wiedner Hauptstrasse 8-10, 1040 Vienna, Austria We determine the out-of-equilibrium production rate of dileptons and prompt photons in strongly coupled N=4 Super Yang-Mills plasma using the AdS/CFT correspondence. Thermalization is achieved via the gravitational collapse of a thin shell of matter in anti-de-sitter spacetime and the subsequent formation of a black hole, which we describe in a quasistatic approximation. Prior to thermalization, the spectral functions of dileptons and photons are observed to oscillate as a function of frequency, but the amplitudes of oscillations decrease when thermal equilibrium is approached. Thu, 14:42 Status of the g-2 of the muon: trouble for the standard model or theorists overconfidence Richard Williams 1, Christian Fischer 2, Tobias Göcke 2 1 University of Graz, Universitätsplatz 5, 8010 Graz, Austria 2 Universität Giessen, Heinrich-Buff-Ring 16, Giessen, Germany A several year old discrepancy at the 2-3 sigma level between precision Standard Model computations of the muon s magnetic moment and experimental measurement defies theory. I quickly review the last measurements, the various contributions to the theory estimate that include a mindboggling 5-loop QED calculation as well as high-order QCD and electroweak corrections, and concentrate especially on the hadronic contributions I will show how progress in the Dyson-Schwinger formulation of Chromodynamics provides a cross-check, extension and improvement over future lattice and existing quark model and effective Lagrangian estimates, highlighting the strengths and weaknesses of the various approaches. Thu, 14:54 Electron-Positron Pair Production in Structured Pulses of Electric Fields Christian Kohlfürst 1, Florian Hebenstreit 1, Reinhard Alkofer 1 1 University of Graz, Universitätsplatz 5, 8010 Graz, Austria The non-perturbative electron-positron pair production (Schwinger effect) in time-dependent pulse-shaped electric fields is investigated. For pulses of experimental interest the employed quantum kinetic formalism reduces the equation for the electron (positron) density to a set of ordinary coupled differential equations of first order. The dynamical effect of electric fields with at least two different time scales within the pulse is studied. First results for an optimization of the particle density yield by pulse-shaping will be given. 46

49 Thu, 15:06 Zwei- und Dreipunktfunktionen zwei-dimensionaler Yang-Mills-Theorie in Landau Eichung Markus Huber 1, Axel Maas 2, Lorenz von Smekal 1 1 Technische Universität Darmstadt, Schlossgartenstrasse 9, Darmstadt, Germany 2 Friedrich-Schiller-University Jena, Max-Wien-Platz 1, Jena, Germany Gittersimulationen und nicht-perturbative Kontinuumsmethoden wie die funktionale Renormierungsgruppe und Dyson-Schwinger-Gleichungen haben unterschiedliche Stärken und Schwächen und ergänzen einander sehr gut. Da auf dem Gitter niedrige Impulse in zwei und drei Dimensionen leichter als in vier Dimensionen erreicht werden können, werden Rechnungen auch damit durchgeführt. Dabei stellte sich heraus, dass das Verhalten in zwei Dimensionen qualitativ anders ist als in drei und vier Dimensionen. Hier präsentieren wir analytische und numerische Ergebnisse von Dyson-Schwinger-Gleichungen, die diesen Unterschied erklären. Eines der Hauptergebnisse ist die Sensibilität der Ergebnisse auf den Bereich mittlerer Impulse, auf welchen Trunkierungen den meisten Einfluss haben. Um die Trunkierungsabhängigkeit zu verkleinern, lösen wir die Propagator- Gleichungen gemeinsam mit der Dyson-Schwinger-Gleichung des Geist-Gluon-Vertex. Thu, 15:18 Polyakov-Loops and the QCD Phase Structure Tina K. Herbst 1, Bernd-Jochen Schaefer 1, Jan Martin Pawlowski 2 1 University of Graz, Universitätsplatz 5, 8010 Graz, Austria 2 Universität Heidelberg, Philosophenweg 16, Heidelberg, Germany We discuss the impact of fluctuations on the chiral and deconfinement phase transition of QCD within an effective model. Thermal and quantum fluctuations are included via the functional renormalisation group. Special emphasis is put on the matter backcoupling to the gauge sector, which has a drastic influence on the phase structure. Thu, 15:30-15:50: Coffee break 47

50 Thu, 15:50-18:00, HS Thu, 15:50 Consequences of an Infrared Divergent Quark 4-Point Function Mario Mitter 1, Reinhard Alkofer 1 1 University of Graz, Universitätsplatz 5, 8010 Graz, Austria Based on the idea that a confining linear rising quark potential can be explained by a 1/k 4 divergence in the quark 4-point function, we find restrictions on the color tensor structure of this divergence. Furthermore, we investigate consequences on other Green functions. Thu, 16:02 Renormalization in Functional Approaches Valentin Mader 1, Reinhard Alkofer 1 1 University of Graz, Universitätsplatz 5, 8010 Graz, Austria In Functional Approaches, correlation functions are calculated self-consistently. Back-coupling effects lead to drastic modification in the renormalization program in quantum field theories. Using the Dyson-Schwinger equations of Yang-Mills theory we investigate the influence of quadratic and logarithmic divergences on the solution process of such equations. Thu, 16:14 What is (not) a Glueball? Andreas Windisch 1, Markus Huber 2, Reinhard Alkofer 1 1 University of Graz, Universitätsplatz 5, 8010 Graz, Austria 2 Technische Universität Darmstadt, Schlossgartenstrasse 9, Darmstadt, Germany We present a short review on what glueballs are and how they can be described theoretically. In particular we discuss a scalar glueball, which is described by the two-point function of the square of the Yang-Mills field strength tensor. The momentum-space operator corresponding to this correlator has been constructed such that dierent gluon-propagators in 2 and 4 dimensions can be plugged into the expression. While the gluon-propagators have been taken from non-perturbative studies, the correlator itself is of lowest order in the coupling. By analytic continuation we extend the solution to complex values of p 2, the square of the external momentum. The structure of the correlator in the complex plane encodes important information of the propagating degree of freedom, such as its mass or whether it is a bound state or not. We perform this investigation numerically by applying a specifically developed procedure which involves Graphics Processing Units to carry out this computationally intensive task [1]. This tool allows us to investigate a variety of gluon propagators of dierent origin, without having to deal with the limitations present due to their complicated integral representations. The aim of this talk is to present not only the procedure used throughout the study, but also to stress what is not sufficient to get a glueball, restricting the ingredients of this highly interesting, experimentally hard-to-prove objects. [1] A. Windisch, R. Alkofer, G. Haase and M. Liebmann, arxiv: [hep-ph]. 48

51 Thu, 16:26 The Role of the Quark-Gluon Vertex Function in the QCD Phase Transition Markus Hopfer 1, Mario Mitter 1, Bernd-Jochen Schaefer 1, Reinhard Alkofer 1 1 University of Graz, Universitätsplatz 5, 8010 Graz, Austria During the last years, intensive theoretical and experimental efforts towards a deeper understanding of the strong interactions between quarks and gluons, the fundamental fields in nature, have been made. In particular, the observed phenomena of confinement and dynamical mass generation were at the focus of many contemporary studies. Up to now, the emergence of these phenomena from the underlying fundamental theory, quantum chromodynamics (QCD), is not understood in detail. Moreover, the transition from the confined hadronic phase to the quark-gluon plasma phase induces a sudden change in the particle masses indicating a relation between these phenomena. As confinement and chiral symmetry breaking are intrinsic properties of the strong interaction in the infrared, they are not accessible by perturbation theory. By relating the Greens functions of the theory, the Dyson-Schwinger formalism offers a non-perturbative description of the dynamics including quantum fluctuations which are mandatory in the vicinity of phase transitions. The quark-gluon vertex is the central object in this context linking the quark with the Yang-Mills sector of the theory. Due to its complexity only models for this vertex are used up to now. The major focus is to replace these models by a detailed numerical investigation, including the relevant tensor structure and probing subsequently the phase diagram of QCD. Thu, 16:38 Properties of the Delta and Omega Baryons from QCD Bound State Equations Reinhard Alkofer 1, Helios Sanchis-Alepuz 1, Richard Williams 1 1 University of Graz, Universitätsplatz 5, 8010 Graz, Austria Based on rainbow-ladder truncated QCD bound state equations properties of the quark core of mesons and baryons are calculated from their respective Bethe-Salpeter and Poincare-covariant Faddeev amplitudes. Results on the spectrum and electromagnetic form factors of Delta/Omega baryons from light to heavy quarks are presented. To evaluate their dependence on the rainbowladder truncated, effective interaction calculations employing two different models have been performed. Thu, 16:58 The sigma meson in a covariant Dyson-Schwinger - Bethe-Salpeter approach Matthias Blatnik 1, Reinhard Alkofer 1, Richard Williams 1 1 University of Graz, Universitätsplatz 5, 8010 Graz, Austria We study the f(600) or σ, the lowest scalar meson resonance, in the framework of a Dyson- Schwinger - Bethe-Salpeter approach which is based on the non-pertubative Green s functions of QCD. The σ has exactly the same quantum numbers as the vacuum, and it plays an important role in dynamical chiral symmetry breaking and in nuclear physics. We investigate the σ starting with a q q state and aim in particular to include the decay into and coupling to two pions. We will give results for the bare, i.e., q q masses of the σ and the π and estimates for the σ mass and decay width. 49

52 Thu, 17:10 Nucleon Compton scattering in the Dyson-Schwinger approach Gernot Eichmann 1 1 University of Graz, Universitätsplatz 5, 8010 Graz, Austria Compton scattering on the nucleon provides a unique tool to probe the nonperturbative structure of the nucleon. It allows access to a range of observables that are subject to studies at major experimental facilities, including: the nucleon s generalized polarizabilities; two-photon contributions to form factors; nucleon structure functions and generalized parton distributions; and protonantiproton annihilation processes. A nonperturbative approach for investigating such phenomena is given by the combination of QCD s Dyson-Schwinger equations with covariant Bethe-Salpeter and Faddeev equations. The framework has been recently applied for describing nucleon and delta elastic and transition form factors, and its systematic extension to Compton scattering, pion electroproduction and nucleon-pion scattering has been outlined. I will discuss recent progress in this area and present first results for the nucleon s Compton scattering amplitude. Thu, 17:22 Matrix Models as unified models of fundamental interactions Harold Steinacker 1 1 University of Vienna, Boltzmanngasse 5, 1090 Vienna, Austria Matrix models have been proposed as a non-perturbative definition of string theory. Basic solutions and mechanisms are discussed for the so-called IKKT model. Space-time can arise as brane solution, while gauge fields arise from fluctuations around stacks of branes. This leads to a braneworld scenario, with many parallels but also differences to more conventional string theory constructions. A overview of recent progress and an outlook is given. 50

53 Fri, 09:00-11:00, HS Fri, 09:00 Producing a new in-house C-14 standard by irradiating graphite Thomas Wieninger 1, Klaus Mair 1, Johannes Sterba 2, Peter Steier 1, Robin Golser 1 1 University of Vienna, Währinger Strasse 17, 1090 Vienna, Austria 2 Vienna University of Technology, Stadionallee 2, 1020 Vienna, Austria Accelerator mass spectrometry (AMS) always performs measurements relative to a standard, which significantly improves the precision. C-14 measurements need a chemical treatment to transform carbon into graphite, to be used in the popular Cs-sputter sources. A homogeneous bulk of several gram of graphite containing C-14 would allow to study the performance of the mass spectrometer independent of sample preparation chemistry. Unfortunately, this material is not available so far. The aim was to produce such a new in-house standard for the VERA facility (University of Vienna). We started from dead (p.e. no C-14) graphite powder and irradiated it with thermal neutrons at the TRIGA Mark II reactor from the Institute of Atomic and Subatomic Physics (TU Vienna). Via the C-13(n, gamma)c-14 reaction we produced a C-14 isotopic abundance in the natural range of The challenge of this work was to deal with an inhomogeneous neutron flux and the low cross section for the mentioned above reaction, compared to the much more efficient N-14(n,p)C-14. The homogeneity of the produced material was successfully verified by measurements of small aliquots. Fri, 09:12 A multi-anode ionisation chamber for AMS at VERA Josef Buchriegler 1, Alfred Priller 1, Oliver Forstner 1, Martin Martschini 1, Peter Steier 1, Robin Golser 1 1 University of Vienna, Währinger Strasse 17, 1090 Vienna, Austria AMS (Accelerator Mass Spectrometry) is a technique to measure long-lived radionuclides with extreme abundance sensitivity below 1E-12. For sufficient isobar suppression at low energies (<1 MeV/amu) a high-resolution detector is required. Based on recent experimental results for the separation of 36Cl from 36S, a new gas ionisation chamber with a multi-anode design was built at VERA (Vienna Environmental Research Accelerator). It provides up to 8 energy loss signals for particle identification. In order to reduce electronic noise special low-capacitive conductors are used inside the gas volume; also the preamplifiers are mounted directly on the detector housing. The dimensions of the Frisch grid [1] and the distances between grid and electrodes were optimized both for short pulse rise times as well as minimum grid-inefficiency [2]. The flexibility of the design concerning the type of detector window, the configuration of anodes and the distances between grid and electrodes makes the detector also well suited for the measurement of heavy ions, e.g. 236U at low energies. Calculations and first experimental results of the detector s performance will be presented. [1] Bunemann O., Cranshaw T. E., Harvey J. A., Design of Grid Ionization Chambers, Canadian Journal of Research 27A (1949) [2] Göök A., Investigation of the Frisch-grid inefficiency by means of wave-form digitization, Dissertation, Örebro Universitet 51

54 Fri, 09:24 Status Report on PERC Gertrud Konrad 1, The PERC Collaboration 2 1 Technische Universität Wien, Stadionallee 2, 1020 Wien, Austria 2 Important open questions of particle physics and cosmology can be addressed with precision measurements in neutron beta decay. Main emphasis lies on the search for evidence of possible extensions to the Standard Model and searches for new symmetry concepts. In general, these measurements are complementary to direct searches in high-energy physics. Observables in neutron decay are abundant: Besides the neutron lifetime, angular correlations involving the neutron spin as well as momenta and spins of the emitted particles are characterized by individual coefficients. These coefficients can be related to the underlying coupling strengths of the weak interaction, including yet unobserved ones. Each coefficient in turn relates to an underlying broken symmetry. With the new facility PERC several symmetry tests based on neutron decay data become accessible. PERC (Proton Electron Radiation Channel) is a novel source of neutron decay products: these are collected by a strong longitudinal magnetic field of 1.5 T directly from inside a neutron guide. This combination provides highest phase space density of decay products. A magnetic mirror of up to 6 T serves to perform precise cuts in phase space, reducing related systematic errors. Altogether, the sensitivity of neutron decay studies will be improved by one order of magnitude. The new beam station PERC is currently under development by an international collaboration and will be installed at the FRM II in Garching, Germany. Besides the physics motivation, the concept, sensitivity, applications, and status of PERC are presented in this talk. Fri, 09:44 Ein Neutronenspinresonator zur Erzeugung Wellenlängen-selektierter Neutronenpulse Christoph Gösselsberger 1, Gerald Badurek 1, Erwin Jericha 1 1 Vienna University of Technology, Stadionallee 2, 1020 Vienna, Austria Im Rahmen dieses Beitrags stellen wir die erstmalige Entwicklung eines Wanderwellen-Neutronenspinresonators zur Erzeugung nahezu beliebig geformter wellenlängenselektierter, polarisierter Neutronenpulse vor. Das Grundprinzip dafür ist die räumliche magnetische Spinresonanz. Dabei werden die polarisierten Neutronen einem räumlich abwechselnden magnetischen Feld ausgesetzt, welches normal zur Polarisationsrichtung angelegt ist. Die Frequenz dieses alternierenden Magnetfeldes ist im Bezugssystem eines einzelnen Neutrons jeweils von dessen Geschwindigkeit und der räumlichen Periode des Resonators abhängig. Sofern diese Frequenz mit der Larmorfrequenz der Neutronen übereinstimmt, welche durch das orthogonal angelegte statische Führungsfeld (Selektorfeld) bestimmt wird, findet ein Pi-Spinflip statt. Durch eine geeignete Justierung dieses Selektorfeldes kann somit eine bestimmte Wellenlänge selektiert werden. Bei der Neuentwicklung wird ein sogenannter Wanderwellenmodus realisiert, bei dem ein wanderndes Magnetfeld, die zu erzeugenden Neutronenpulse durch den Resonator begleitet. Bei dieser Umsetzung erscheinen um 2 Größenordnungen kürzere Pulszeiten als bei einem traditionellen Resonator realisierbar. Der Aufbau aus Einzelelementen hat den wesentlichen Vorteil, dass die erzeugten Magnetfelder beliebig geformt und somit für den Betrieb ungewollte Nebenmaxima in den selektierten Wellenlängenspektren eliminiert werden können. Außerdem können durch bloßes Einstellen der Ströme sowohl die Wellenlängenverteilung als auch die Zeitstruktur nahezu beliebig justiert werden. Wir stellen hier sowohl die Designstudie als auch erste recht vielversprechende Mess- Resultate zweier Resonator-Prototypen vor und gehen auf mögliche zukünftige Anwendungen ein (Strahlpräparation bei PERC, neuartiges 3-Achsen-Spektrometer, Erzeugung von maßgeschneiderten Neutronenpulsen an der ESS). 52

55 Fri, 09:56 Magnetic Field System of PERC Xiangzun Wang 1 1 Vienna University of Technology, Stadionallee 2, 1020 Vienna, Austria The beam station PERC (Proton Electron Radiation Channel) is a new kind of spectrometer for neutron beta decay experiments, aiming to achieve precise measurements of energy spectra of electrons and protons (e-/p+) from free neutron decay, as well as various angular correlation coefficients that represent the properties of the weak and strong interactions. The main instrument of PERC provides a static magnetic field supported by a series of superconducting magnets, to collect and guide the charged decay e-/p+ particles from the decay to the detection area. To obtain high efficiencies and suppressed error levels, the strengths of the magnetic field have a functional distribution, with which the e-/p+ can be selected and defined due to their emission angles. In order to realize precise measurements, the decay e-/p+ are required to be transported with distortion of the observables below Hence the functional magnetic fields must be well defined and homogeneous. To fulfil the requirements of systematics and physics, the magnet system of PERC is delicately designed with a dromedary geometry. The properties of the magnetic fields, the e-/p+ behaviors and the systematic effects are well studied in the simulations. Additionally, the practical and experimental factors are considered in the design of PERC, including the manufacture requirements, the tolerances of the field functions due to external influences, the properties of superconducting wire, and the magnetic forces and torques on the components. Fri, 10:08 Calibration of the ATLAS electromagnetic calorimeter at the per mill level Florian Teischinger 1 1 Vienna University of Technology, Wiedner Hauptstrasse 8-10, 1040 Vienna, Austria ATLAS is one of the experiments built to explore new physics at the TeV with proton-proton collisions at the Large Hadron Collider. The ATLAS experiment will briefly described with emphasis on the ATLAS Liquid Argon electromagnetic calorimeter, this talk will concentrate on the performance and calibration of the electron reconstruction during the 2011 and 2012 data taking periods. Over the past years a calibration method for the energy scale of the liquid argon calorimeter using the distribution of the ratio of the electron energy measured by the calorimeter itself and the momentum measured by the Inner Tracking detector was developed. Results of this powerful calibration method using electrons from W and Z decays and combining the calorimetry and tracking information, will be presented. It will be shown how scale factors in fine pseudo-rapidity bins can be extracted with a precision at the per mill level. These results will be compared to other calibration methods used in ATLAS. It will be demonstrated how the linearity of the response of the electromagnetic calorimeter can be measured in situ and how the passive material in front of the calorimeter can be estimated. Finally, the impact of this precise calibration of the electromagnetic calorimeter on selected physics measurements will be presented. 53

56 Fri, 10:20 The Integrated Simulation Framework A novel Detector Simulation Approach in the ATLAS Experiment Elmar Ritsch 1, Anna Usanova 1, Peter Sherwood 2, Francisca Garay Walls 3, Andreas Schaelicke 3, Andreas Salzburger 4, Robert Duane Harrington Jr 3, Julia Fischer 5, Michael Duehrssen-Debling 4 1 University of Innsbruck, Technikerstraße 15, 6020 Innsbruck, Austria 2 University College London, Gower Street, London WC1E 6BT, UK 3 The University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ, UK 4 CERN, 1211 Geneva 23, Switzerland 5 Bergische Universität Wuppertal, Gaußstrasse 20, Wuppertal, Germany With the increasing amount of delivered luminosity by the Large Hadron Collider (LHC) at CERN, the demand for Monte Carlo simulated data grows accordingly. Given the computing resources of the ATLAS experiment this introduces strict requirements on detector simulation which is, in general, a very CPU intensive task. The Integrated Simulation Framework (ISF) is a completely new approach in optimizing ATLAS detector simulation given the need for high quality physics analyses on one side and restrictions on computing resources on the other. ISF builds a framework that allows to mix different simulation engines on a particle level for the same event. By doing so, a gain of simulation time per event can be achieved if particles which are less relevant for subsequent analysis are e.g. done using fast simulation approaches. ISF combines the existing simulation engines used in ATLAS, which contain the Geant4 toolkit, a fast parameterized calorimeter simulation and a fast track simulation. This talk will discuss fundamental concepts, occurred problems that were solved during the design process of this framework along with first results obtained using the new ISF prototype in ATLAS. Fri, 10:32 Radiation-hard silicon sensors for the CMS tracker upgrade Bernhard Lutzer 1 1 Austrian Academy of Sciences, Nikolsdorfer Gasse 18, 1050 Vienna, Austria The Compact Muon Solenoid (CMS) experiment at the LHC at CERN is currently in operation and delivering promising and outstanding results. This particle detector experiment consists out of different types of detectors of which the Tracker is a very important one. It is made out of silicon-based strip detectors which perform very well at the moment. But due to the radiation damage imposed on these detectors, caused by the high fluences in the near-to-interaction-point region these silicon strip detectors will loose their detection ability with time and need to be eventually replaced by new a new tracker. Also the upgraded LHC which is planned to be in operation in 2020 will deliver a higher luminosity which requires very radiation-hard materials for the new detectors. Therefore a campaign is undergoing to determine which material is the most suitable for such challenging experimental conditions. Different materials for the wafer with different thicknesses are characterized with test-structures and then irradiated with protons at Karlsruhe or with neutrons at TRIGA-reactors in Ljubljana or Vienna to simulate the conditions after several years of operation in the detector. These studies which are presented in this talk are conducted at HEPHY Vienna and will support the decision for the material used for building the upgraded CMS tracker. 54

57 Fri, 10:44 Development and Production of Silicon Particle Detectors in Austria Edwin Frühwirth 1 1 Austrian Academy of Sciences, Nikolsdorfer Gasse 18, 1050 Vienna, Austria In particle physics experiments such as the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) at CERN large numbers of silicon based strip sensors are needed. These sensors are able to precisely detect particles generated in high energy proton-proton collisions and therefore allow reconstructing particle tracks. So far only a few vendors were capable of producing silicon strip sensors with the quality needed in particle physics experiments. Together with an Austrian-based semiconductor manufacturer the Institute of High Energy Physics (HEPHY) (of the Austrian Academy of Sciences) developed such sensors. This talk presents the development, production and electrical characterization of the first silicon strip sensors produced in Austria. The results from the first measurements presented in this talk demonstrate the good quality of the newly developed sensors and offer the possibility to establish the Austrian-based semiconductor manufacturer as a high quality vendor for particle physics detectors. Fri, 11:00-11:30: Coffee break 55

58 Fri, 11:30-13:30, HS Fri, 11:30 Monitoring of the radiation induced effects of the CMS Tracker Wolfgang Treberer-Treberspurg 1 1 Austrian Academy of Sciences, Nikolsdorfer Gasse 18, 1050 Vienna, Austria The tracker of the CMS experiment at the LHC presents the largest silicon device ever built. Although its functionality is addressed to particle physics it also presents a unique opportunity to study well documented radiation damage effects under very specific circumstances. During their lifetime the silicon modules have to withstand up to E15 traversing particles per cm 2. However, the silicon sensor characteristic changes while ionizing radiation is damaging the crystal lattice. Each of the modules is featured with a detector control unit, recording amongst other things every single temperature, dark current and voltage value. Periodically dedicated runs are performed to determine the depletion voltage of each module. The dark current and its annealing behaviour in respect to temperature are measured as soon as the modules are turned on. All these data are used in simulations to expand existing models and deliver predictions concerning the tracker performance in the same time. The talk will present recent results, which have been considered in future constructions of the tracker, especially concerning cooling. Fri, 11:42 Belle II Silicon Vertex Detector: Mechanics Immanuel Gfall 1, Thomas Bergauer 1, Annekathrin Frankenberger 1, Markus Friedl 1, Christian Irmler 1, Manfred Valentan 1, Paul Doljeschi 1, Dusko Smiljic 1 1 Austrian Academy of Sciences, Nikolsdorfer Gasse 18, 1050 Vienna, Austria The Belle experiment at KEK in Tsukuba, Japan and its precision measurements have led to the justification of the Nobel Prize earned by Kobayashi and Maskawa in In June 2010, the machine was brought to a halt for a promising future, namely an upgrade to Belle II which will be completed until By this time all important components are to be exchanged for an unprecedented performance boost of the accelerator (KEKB) and the Belle Detector. With this upgrade, KEKB will become SuperKEKB and beat its own luminosity world record ( cm 2 s 1 ) by a factor of 40. The core of the Belle II Experiment is composed of a DEPFET Pixel Detector, which is surrounded by the Silicon Vertex Detector (SVD). The SVD is located close to the beam pipe to allow high precision vertex reconstruction. The proximity to the beam pipe and the high beam currents result in a very high level of background radiation for the SVD that both, the electronics and the mechanics have to cope with. The Origami sensor design was developed to provide a fast readout system at a very good signal to noise ratio. This design comes with a great performance increase that is able to fulfill with the new Belle II requirements. Nevertheless it is important to implement a light and yet stable mechanical construction that can withstand the radiation and temperature conditions without compromising the detector capabilities. 56

59 Fri, 11:54 Belle II Silicon Vertex Detector: Cooling Annekathrin Frankenberger 1, Markus Friedl 1, Thomas Bergauer 1, Immanuel Gfall 1, Manfred Valentan 1, Christian Irmler 1, Paul Doljeschi 1, Dusko Smiljic 1 1 Austrian Academy of Sciences, Nikolsdorfer Gasse 18, 1050 Vienna, Austria At the KEK, the High Energy Accelerator Research Organization in Tsukuba, Japan, currently the B-Factory KEKB and its experiment, the Belle detector get upgraded, aiming a higher luminosity. The improved Super B-Factory will reach a luminosity of cm 2 s 1 which is 40 times higher than the previous luminosity world record achieved there. For precise decay vertex measurements, a new silicon vertex detector (SVD) is required. The newly designed Belle II SVD comes along with a modern cooling system. The new Belle II SVD with its new Origami readout scheme requires an efficient cooling system for thermal control of the front-end electronics inside the detector volume. One of the most important figures of merit for vertex detectors is the amount of material seen by particles traversing the detector, therefore the material budget has to be kept as low as possible. To minimize the material budget, an evaporative CO2 cooling system has been chosen. CO2 provides excellent thermo-dynamical properties regarding its high heat transfer capability of evaporating CO2. This leads to a much smaller tube diameter and therefore lower mass inside the detectors active volume, compared to using fluorocarbons like conventional cooling systems do. The 2PACL (Two-Phase Accumulator Controlled Loop) developed at Nikhef provides a stable and easily controllable detector cooling system, completely fulfilling the experiments requirements. Integrating the cooling system into the heart of the Belle II detector is difficult and investigations are ongoing to meet the required material budget and space constraints. Fri, 12:06 Low-momentum track reconstruction in the vertex detector of Belle II Jakob Lettenbichler 1, Rudolf Frühwirth 1, Moritz Nadler 1 1 Austrian Academy of Sciences, Nikolsdorfer Gasse 18, 1050 Vienna, Austria The vertex detector of the Belle II experiment will consist of two pixel layers (PXD) and four double-sided strip layers (SVD). While tracks with a transverse momentum above 100 GeV/c are seen in the Central Drift Chamber (CDC), tracks with lower transverse momentum, which are important in certain physics channels, have to be reconstructed in PXD and SVD only. Online track reconstruction, required for data reduction in the PXD, is even more difficult, as only the four SVD layers can be used. We present the strategy for low-momentum track finding in the SVD and SVD/PXD system. It is based on a cellular automaton, which is preceded by several filter stages designed to reduce the combinatorics. The subsequent track fit is performed using the GENFIT toolbox, which has been adapted to the specific features of low-momentum pions and their interaction with the detector material. We present results from simulated data, including background from the detector and the accelerator. 57

60 Fri, 12:18 Forward Tracking in a Linear Collider Detector Winfried Mitaroff 1, Robin Glattauer 1, Rudolf Frühwirth 1 1 Austrian Academy of Sciences, Nikolsdorfer Gasse 18, 1050 Vienna, Austria The International Large Detector (ILD) is one of two approved experiments at ILC, the global project for a future linear e-e+ collider with center-of-mass energy up to 1 TeV. A modified version is under study for CLIC, an alternative project for e-e+ collisions up to 3 TeV. The forward tracking part of ILD (FTD) consists of silicon pixel and micro-strip disks between beam tube and central TPC. Precise track reconstruction in these regions relies on an efficient track search. For processing the measurements of FTD within ILD s software framework, we have developed a new and powerful stand-alone forward track search, based on 3 steps: a Cellular Automaton, a Kalman Filter, and a Hopfield Neural Network. We present this package, its methods and merits. Fri, 12:30 Computational Uncertainties in Public BR(B X s γ) Codes Sebastian Frank 1, Sabine Kraml 2, Nazila Mahmoudi 3,4, Shibi Rajagopalan 2 1 Austrian Academy of Sciences, Nikolsdorfer Gasse 18, 1050 Vienna, Austria 2 LPSC Grenoble 53, rue des Martyrs Grenoble, France 3 Laboratoire de Physique Corpusculaire Clermont-Ferrand, Campus des Czeaux 24, avenue des Landais BP Aubire Cedex, France 4 CERN, Office Building 53, 1211 Geneva 23, Switzerland The branching ratio BR(B X sγ) is a sensitive probe for physics beyond the SM and thus an important constraint for parameter fits of SUSY models. It is therefore highly important to have a good assessment of theoretical and computational uncertainties, including the differences in the implementations and/or approximations used in public computational tools. We perform a detailed comparison of the various public BR(B X sγ) codes, evaluating the differences of the SM and MSSM results and their dependence on relevant parameters. The impact on SUSY fits is demonstrated via a global Bayesian analysis using Markov Chain Monte Carlo (MCMC) techniques. 58

61 Fri, 12:42 Recovery Time and Double Hit Resolution Measurements of SiPMs Using a Double Pulsed Laser Lukas Gruber 1, Stefan Brunner 1, Catalina Curceanu 2, Johann Marton 1, Antonio Romero Vidal 3, Alessandro Scordo 2, Ken Suzuki 1, Oton Vazquez Doce 4 1 Österreichische Akademie der Wissenschaften, Boltzmanngasse 3, 1090 Vienna, Austria 2 NFN - LNF, Via E. Fermi 40, Frascati (Roma), Italy 3 Universidade de Santiago de Compostela, Ra Xos Mara Surez Nez, Santiago de Compostela, Spain 4 Technische Universität München, James-Franck-Str. 1, Garching, Germany The so-called Silicon Photomultiplier (SiPM) is a relatively novel type of semiconductor photo detector which consists of multiple pixels of Avalanche Photodiodes (APDs) working in Geigermode. One of the important parameters of photo sensors is the performance in high rate environments. For experiments like AMADEUS within the KLOE detector at LNF, where the detector system will be exposed to a very high rate shortly after the e+/e- injection, an overall rate capability is required. A charged kaon decay-mode tagging to distinguish K+ and K- is also very crucial to suppress the background. Therefore, a good double hit resolution is required. In order to characterize the rate capability and the double hit resolution, we performed an experimental study to determine the cell recovery time for various SiPMs of different vendors. The measurements are performed using a blue (407 nm) pulsed laser with 25 ps pulse width. We evaluated the recovery time constant by measuring the sensor response to two consecutive laser pulses, with a varying relative time difference of a few ns up to a few 100 ns, with a waveform digitizer (CAEN V1742, 5 GHz sampling). The two pulses are generated by splitting the laser signal, delaying one of the signals and merging again. The delay of the second pulse is done by coupling the light into optical fibers of different length (1 m to 200 m). The influence of the overvoltage on the recovery time is also studied. 59

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63 5 Physics Teachers (LHS) HS Physics in School Physik und Schule Leopold Mathelitsch, Wednesday, 19 th September 2012, HS :30-15:00 Time Presenter Title 14:30-15:00 Mario Müller Mikrokraftwerke Wednesday, 19 th September 2012, HS :00-16:15 SchülerInnen stellen vor Presenter Title Die Teslaspule in Theorie und Experimenten Stefan Mazuheli Nadine Schmalzer Materiewelleninterferometrie Halbleiter und Charakterisierung von Thomas Kamencek Halbleiternanostrukturen Nanobeschichtungen Nanotechnologie in Theorie und Praxis Thomas Mülleder Physikolympiade 2012 International Young Physicists Tournament 2012 Wednesday, 19 th September 2012, HS :15-17:00 16:15-16:30 Victor Franz Hess Prize 16:30-17:00 Fachausschuss Physik und Schule 61

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65 6 Acoustics (AKU) LS Acoustics Akustik Holger Waubke, Thursday, 20 th September 2012, LS :00-11:00 Time Presenter Title 10:00-10:20 David Pirró Alexander Wankhammer Acoustic Interface for Tremor Analysis Quellbreite von frontalen Phantomschallquellen: 10:20-10:40 Matthias Frank Wahrnehmung, Mes- sung und Modellierung 10:40-11:00 Franz Zotter Einfache, auf Kammfilter beruhende Phantomschallquellenaufweitung 11:00-11:30 Coffee break Thursday, 20 th September 2012, LS :30-15:50 Gaussian Closure Technik für die Bestimmung 14:30-14:50 Holger Waubke analytischer Lösungen für ein hysteretisches Modell von Bouc 14:50-15:10 Peter Balazs Frame Theory for Acoustical Applications 15:10-15:30 Thibaud Necciari Auditory time-frequency masking for stimuli with maximal concentration in the time-frequency plane 15:30-15:50 Coffee break 63

66 Thursday, 20 th September 2012, LS :50-18:00 15:50-16:10 Robert Baumgartner Modelle zur Vorhersage der Schallquellenlokalisation in Sagittalebenen Beschleunigung der numerischen 16:10-16:30 Harald Ziegelwanger Berechnung von Außenohrübertragungsfunktionen ExpSuite: Software Framework zur 16:30-16:50 Michael Mihocic Durchführung psychoakustischer Experimente mit akustischer, elektrischer und visueller Stimulusdarbietung 16:50-17:10 Christian Kasess Bayesian estimation of the area function of nasals 17:10-17:30 Wolfgang Kreuzer Wavelets on the sphere 17:30-17:50 Martin Pobitzer Eigenmoden Raummoden; theoretische Betrachtungen und Simulationen in COMSOL Multiphysics 64

67 Thu, 10:00-11:00, LS Thu, 10:00 Acoustic Interface for Tremor Analysis David Pirró 1, Alexander Wankhammer 1, Alois Sontacchi 1, Robert Höldrich 1 1 Universität für Musik und darstellende Kunst Graz, Inffeldgasse 10/3, 8010 Graz, Austria Tremor is the most common movement disorder. It is defined as a rhythmic and involuntary oscillation of a body part, caused by reciprocal nervous innervations of muscles. The most common forms include the essential tremor, parkinsonian tremor, dystonic tremor and psychogenic tremor. It is well-known that each different tremor form can be the symptom of a specific disease. Therefore, reliable classification and quantification of different tremor types is of strong clinical interest, as it could be crucial in order to provide adequate treatment and medication for the patient. In many cases a confident clinical diagnosis mainly based on the visual analysis of a tremor by highly specialized neurologists experienced in movement disorders is possible. Nevertheless, in some situations uncertainty remains. Therefore, further investigations based on structural and functional imaging, video analysis, accelerometry and other electrophysiological investigations can be necessary. Although such methods offer important additional information for a final diagnosis, the ex-post analysis and interpretation of recorded data is typically very time-consuming and expensive. The new sonification methods presented in this paper aim at extending established tremor analysis methods by an acoustical interface for tremor diagnosis. Based on real time sonification of acceleration data, detailed information on the temporal as well as spectral characteristics of tremor could be made audible to the neurologist while interacting with the patient. As sonification could provide an additional modality to perception, it would allow for a holistic analysis of the observed tremor avoiding the major drawbacks of ex-post analysis methods. Thu, 10:20 Quellbreite von frontalen Phantomschallquellen: Wahrnehmung, Messung und Modellierung Matthias Frank 1 1 Universität für Musik und darstellende Kunst Graz, Inffeldgasse 10/3, 8010 Graz, Austria Phantomschallquellen sind Hörereignisse, die an einem Ort wahrgenommen werden, an dem sich keine Schallquelle befindet. Die einfachste Art Phantomschallquellen mithilfe von Lautsprechern zu erzeugen stellt die Stereophonie dar. Phantomschallquellen unterscheiden sich in ihrer wahrgenommenen Qualität von realen Schallquellen. Einer dieser Unterschiede ist eine Aufweitung der wahrgenommenen Quellbreite. Dieser Beitrag beschäftigt sich mit der Quellbreite von frontalen Phantomschallquellen. Die Phantomschallquellen werden durch gleichzeitigen Betrieb von 2 bzw. 3 symmetrisch aufstellten Lautsprechern erzeugt. Neben der Anzahl an aktiven Lautsprechern wird auch der Abstand zwischen diesen variiert. Die Wahrnehmung der Quellbreite wird zunächst in einem Hörversuch evaluiert. Die Versuchsergebnisse werden anschließend mit zwei aus der Raumakustik bekannten Messgrößen für die Quellbreite (interauraler Kreuzkorrelationskoeffizient IACC und Seitenschallgrad LF) verglichen. Weiters wird eine angepasste Methode zur Messung des Seitenschallgrades vorgestellt, die die Eignung dieser Messgröße für simultanen Schalleinfall verbessert. Der Beitrag schließt mit einem einfachen physikalischen Modell zur Vorhersage der wahrgenommenen Quellbreite. 65

68 Thu, 10:40 Einfache, auf Kammfilter beruhende Phantomschallquellenaufweitung Franz Zotter 1, Matthias Frank 1 1 Universität für Musik und darstellende Kunst Graz, Inffeldgasse 10/3, 8010 Graz, Austria Die geeignete Ansteuerung eines symmetrisch zum Hörplatz stehenden Lautsprecherpaares kann ein Hörereignis variabler Breite erzeugen. Am schmalsten ist dieses Hörereignis, die so genannte Phantomschallquelle, wenn beide Lautsprecher mit dem selben Signal versorgt werden. Es ist allgemein bekannt, dass sich die wahrgenommene Richtung dieser Phantomschallquelle durch breitbandige Laufzeit- und Pegelunterschiede an variable Richtungen zwischen den Lautsprechern lenken lässt. Darüber hinaus beschreibt die Literatur über Stereophonie, dass entlang der Frequenz uneinheitliche Pegel- und Laufzeitunterschiede dazu geeignet sind, die Phantomschallquelle aufzuweiten. Eine kürzlich vorgestellte laufzeitbasierte Methode ist zwar effizient, scheint aber nur am zentralen Abhörplatz gut zu funktionieren. Dieser Beitrag stellt deshalb einen effizienten pegelbasierten Ansatz vor und vergleicht beide Ansätze an einem seitlichen Abhörplatz. 66

69 Thu, 14:30-15:30, LS Thu, 14:30 Gaussian Closure Technik für die Bestimmung analytischer Lösungen für ein hysteretisches Modell von Bouc Holger Waubke 1 1 Österreichische Akademie der Wissenschaften, Wohllebengasse 12-14, 1040 Wien, Austria Das Modell von Bouc wurde für die mathematische Beschreibung des hysteretischen Verhaltens von Gummi entwickelt [1]. Im Vortrag sollen weitgehend analytische Beschreibungen für die Momente einer mehrdimensionalen Normalverteilung der Zustandsgrößen des Modells von Bouc auf Basis der Gaussian Closure Technik [2] gewonnen werden. Dabei wird ein explizites Zeitschrittverfahren für den instationä ren Fall und ein implizites nichtlineares Gleichungssystem für den stationären Fall hergeleitet [3]. Das implizite Gleichungssystem läßt sich rasch lösen. Dabei treten keine Parameterkombinationen auf, die zu chaotischen Verhalten, wie bei der statistischen Linearisierung führen. [1] Bouc, R.: Forced Vibrations of a Mechanical System with Hysteresis (abstract), Proceedings of the 4th Conference on Nonlinear Oscillations, Prag, 1967, pp.315 [2] Caughey, T.K.; Dienes, J.K: Analysis of a Nonlinear First-Order System with a White Noise Input, Journal of applied Physics, Vol.33 No.11 Nov. 1961, pp [3] Waubke, H. : Moment-Closure Technik zur Abschätzung der elasto-plastischen Reaktion von Stockwerksrahmen auf zufällige Belastungen aus Windereignissen, Habilitation, Berichte aus dem konstruktiven Ingenieurbau, TU München, 1/1999 Thu, 14:50 Frame Theory for Acoustical Applications Peter Balazs 1 1 Österreichische Akademie der Wissenschaften, Wohllebengasse 12-14, 1040 Wien, Austria Application-oriented mathematics develops theoretical results and new mathematical concepts, motivated by application. The application-oriented approach produces results significant both for mathematics and the applied sciences. In this talk we will present an overview of new concepts in frame theory motivated by signal processing and acoustical applications. We will present a survey over general frame theory, time-frequency analysis and the theory of frame multipliers, as well a their applications in acoustics. 67

70 Thu, 15:10 Auditory time-frequency masking for stimuli with maximal concentration in the time-frequency plane Thibaud Necciari 1, Bernhard Laback 1, Peter Balazs 1, Sophie Savel 2, Sabine Meunier 2, Sølvi Ystad 2, Richard Kronland-Martinet 2 1 Österreichische Akademie der Wissenschaften, Wohllebengasse 12-14, 1040 Wien, Austria 2 Laboratoire de Mécanique et dacoustique, 31 chemin Joseph Aiguier, Marseille Cedex 20, France Many audio applications involving sound analysis-synthesis (e.g., virtual reality, sound design, perceptual audio coding) use time-frequency (TF) representations such as the Gabor and wavelet transforms. These transforms allow decomposing any natural sound into a set of elementary functions or atoms that are well localized in the TF plane. For such applications, it is often required that the signal representation matches human auditory perception. On that purpose, the present study investigated auditory TF masking using stimuli with maximal concentration in the TF plane. Stimuli (masker and target) were Gaussian-shaped sinusoids with an equivalent rectangular bandwidth of 600Hz and an equivalent rectangular duration of 1.7ms (0-amplitude duration of 9.6ms). The masker had a carrier frequency of 4kHz and a level of 60dB SL. The target was shifted either in time, in frequency, or both relative to the masker. The results of the TF shifts provide the TF spread of masking produced by a maximally-compact Gaussian TF atom. These results constitute a crucial basis for predicting masking in the TF representations of sounds. The results of the time and frequency shifts allowed to show that a simple superposition of frequency and temporal masking functions does not provide an accurate representation of the measured TF masking function. This reveals the inaccuracy of the simplistic models of TF masking currently implemented in some perceptual audio codecs. Thu, 15:30-15:50: Coffee break 68

71 Thu, 15:50-18:00, LS Thu, 15:50 Modelle zur Vorhersage der Schallquellenlokalisation in Sagittalebenen Robert Baumgartner 1, Piotr Majdak 1, Bernhard Laback 1 1 Österreichische Akademie der Wissenschaften, Wohllebengasse 12-14, 1040 Wien, Austria Die Fähigkeit, Schallquellen in Sagittalebenen zu lokalisieren, basiert auf spektralen Merkmalen, die aus der Filterung des einfallenden Schalls durch Torso, Kopf und Ohrmuschel resultieren. Obwohl diese Filterwirkung bereits seit langer Zeit bequem mittels sog. head-related transfer functions (HRTFs) beschrieben werden kann, erlauben derzeitige Modelle noch nicht die Vorhersage der Schallquellenlokalisation in Sagittalebenen. Dieser Beitrag beschreibt existierende Modelle zur Vorhersage der Schallquellenlokalisation sowie mögliche Erweiterungen für den verbesserten Vergleich mit psychoakustischen Experimenten. Es wird eine Methode zur Vorhersage der individuellen Lokalisationsleistung mit individuellen HRTFs vorgestellt. Weiters wird der Effekt der Einbettung verschiedener Modelle des peripheren Gehörs im Lokalisationsmodell auf die Vorhersage der Lokalisation unter diversen Bedingungen beschrieben. Thu, 16:10 Beschleunigung der numerischen Berechnung von Außenohrübertragungsfunktionen Harald Ziegelwanger 1, Wolfgang Kreuzer 1, Piotr Majdak 1 1 Österreichische Akademie der Wissenschaften, Wohllebengasse 12-14, 1040 Wien, Austria Außenohrübertragungsfunktionen (engl. head-related transfer functions, HRTFs) ermöglichen die Lokalisation von Schallquellen bei binauraler oder transauraler Wiedergabe und werden üblicher Weise in einem reflexionsarmen Raum unter Freifeldbedingung für eine begrenzte Anzahl an Positionen akustisch gemessen. Die Berechnung von HRTFs über die Randelementemethode stellt eine gut geeignete Alternative dar, da sie unter Ausnutzung der Reziprozität (Tausch von Quelle und Empfänger) effizient die Simulation des durch den Zuhörer gestörten Schallfeldes im Freifeld und somit die Berechnung der HRTFs für beliebige Positionen im Raum ermöglicht. Dafür genügt allein die Kenntnis der Geometrie von Pinna, Kopf und Torso, welche die Filterwirkung verursacht und durch bildgestützte Messverfahren (3D-Laserscan) oder durch bildgebende Messverfahren (Kernspintomographie) als 3D-Mesh erfasst werden kann. Um die HRTFs für den gesamten hörbaren Frequenzbereich berechnen zu können, muss das zugrundeliegende Mesh eine hohe Genauigkeit aufweisen (ca Elemente pro Wellenlänge). Eine höhere Genauigkeit bewirkt allerdings eine längere Rechendauer bei der Simulation. In diesem Vortrag werden verschiedene Ansätze zur Reduktion der Rechendauer bei der HRTF-Berechnung über die Randelementemethode vorgestellt. Es werden numerische Optimierungen wie zum Beispiel ein parametrisches Mesh, die Fast-Multipole- Methode oder H/H-Matrizen diskutiert. Aufgrund der optisch schwer erfassbaren und komplexen Struktur der Pinna wird vorgeschlagen ein strukturiertes Pinna-Modell zu entwickeln und an die individuelle Anthropometrie anzupassen. 69

72 Thu, 16:30 ExpSuite: Software Framework zur Durchführung psychoakustischer Experimente mit akustischer, elektrischer und visueller Stimulusdarbietung Michael Mihocic 1, Piotr Majdak 1, Bernhard Laback 1 1 Österreichische Akademie der Wissenschaften, Wohllebengasse 12-14, 1040 Wien, Austria In diesem Beitrag wird ExpSuite, eine Software zur Durchführung psychakustischer Experimente vorgestellt. ExpSuite besteht aus einem Framework und darauf basierenden Applikationen. Sie profitiert von der Rapid Application Development -Umgebung in.net, die eine schnelle Entwicklung der Experimente ermöglicht. Durch den modularen Aufbau können Applikationsprogrammierer die Eigenschaften der Applikationen selbst definieren: Generierung einer Item list mit Testparametern und Ergebnissen, Erzeugung und Wiedergabe der Stimuli, Ablauf des Experiments und Auswertung der Ergebnisse. Das Framework unterstützt prozedurale Eigenschaften wie zeitliche Struktur (adaptive und ineinander verschachtelte Abläufe), Parametrierung experimenteller Schritte, Steuerung über Joypad, Maus, Tastatur, Touchscreen, oder Positionserfassungsysteme. Damit kann sich der Applikationsprogrammierer auf die Entwicklung des experimentellen Designs konzentrieren. Mit der direkten Anbindung an Matlab steht ExpSuite- Applikationen eine Vielfalt von Matlab Funktionen zur Verfügung, die auch zur direkten Auswertung der Ergebnisse verwendet werden können. Die Ausgabe der Stimuli in vektororientierter Form kann über akustische Audiogeräte oder als elektrische Stimulation über ein Cochleaimplantat- Interface erfolgen. Das Programm Pure Data (pd) übernimmt die akustische Signalverarbeitung in Echtzeit (komplexe Filterung und Signalgenerierung), die Ausgabe der Stimulationsdateien, sowie die simultane Aufnahme und Wiedergabe mehrerer Audiokanäle. Zur Echtzeitdarstellung einer virtuellen visuellen Welt wird GEM unter pd verwendet. Die elektrische Stimulation zur Durchführung von Experimenten mit Cochleaimplantat-Trägern erfolgt über die Research Interface Boxen (RIBs), die eine binaural synchronisierte Stimulation von Implantaten unterstützen. Exp- Suite wird am Institut für Schallforschung entwickelt und ist unter frei verfügbar. Thu, 16:50 Bayesian estimation of the area function of nasals Christian Kaseß 1, Wolfgang Kreuzer 1 1 Österreichische Akademie der Wissenschaften, Wohllebengasse 12-14, 1040 Wien, Austria Computational acoustical models for speech production and analysis have been of major research for decades. Most commonly, one-tube models are employed which show a direct correspondence to all-pole filter models. However, such models are not an adequate representation for nasal stops and nasalized vowels due to the coupling to the nasal tract. Thus, at least one additional coupled tube is necessary to model the spectral dips typically appearing in nasal speech signals. Typically, the estimation of such branched-tube area functions is based on pole-zero models. Here, the tube model areas are estimated directly from the log-envelope of the spectrum of the speech signal. A variational Bayesian scheme under Gaussian assumptions is employed that utilizes probabilistic priors to enforce smoothness of the estimated area function. Different prior variances are tested on tokens of /m/ recorded from several speakers. Furthermore, results of an un-regularized non-linear scheme are compared to the Bayesian estimation. The model error and marginal likelihood show that mild smoothness assumptions yield the best results. The estimation error for the un-regularized scheme is in a comparable range, however, the reflection coefficients and thus the area functions vary considerably more within a subject than for the Bayesian scheme. 70

73 Thu, 17:10 Wavelets on the sphere Wolfgang Kreuzer 1 1 Österreichische Akademie der Wissenschaften, Wohllebengasse 12-14, 1040 Wien, Austria For numerous applications in acoustics a spatial representation of wave fields supporting a local other than a global resolution is advantageous. Such applications range from wave field synthesis to numerical methods like the fast multipole method. As an alternative to the often applied spherical harmonic analysis, wavelets or - more general - frames can achieve a more efficient representation. Although wavelet analysis has been proven to be useful in many applications in audio and signalprocessing and wavelets on the sphere have been of research interest in geophysics and computer vision for several years now, their potential for representing three-dimensional acoustic wave fields has not been fully explored yet. In this talk, a short overview of available methods to construct and use wavelets (and frames) on the sphere will be presented. Thu, 17:30 Eigenmoden - Raummoden; theoretische Betrachtungen und Simulationen in COMSOL Multiphysics Martin Pobitzer 1, Stefan Plagg 1, Gerhard Graber 1 1 Graz University of Technology (TU Graz), Inffeldgasse 16c/EG, 8010 Graz, Austria Dieser Beitrag beschäftigt sich mit der Ausbildung von stehenden Wellen im Raum. Da in diesem Zusammenhang die Begriffe Eigenmoden und Raummoden oft verwechselt werden, ist einer der Kernpunkte die Unterschiede beider Begriffe aufzuzeigen. Nach einer Einführung in die Thematik wird eine Eigenfrequenzanalyse für verschiedene Raumtypen durchgeführt und der Einfluss von verschiedenen Wand- und Deckenformen untersucht. Die Ergebnisse werden unter anderem mit Hilfe von Animationen präsentiert. Der zweite Teil behandelt die Frequenzbereichsanalyse, mit deren Hilfe der Einfluss von Quellposition und Beobachter- bzw. Mikrofonposition auf die Raummodenausformung untersucht wird. Die Arbeit wurde im Rahmen eines Bachelorseminars am Institut für Signalverarbeitung und Sprachkommunikation (spsc) der Technischen Universität Graz erstellt. 71

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75 7 Atoms, Molecules, Quantum Optics and Plasmas (AMP) LS Atoms, Molecules, Quantum Optics and Plasmas Atome, Moleküle, Quantenoptik und Plasmen: Hanns-Christoph Nägerl, Thursday, 20 th September 2012, LS :00-11:00 Time Presenter Title Carbohydrate-Aromatic Complexes 09:00-09:20 Thomas Betz Investigated by Broadband Microwave Spectroscopy 09:20-09:40 Andreas Hauser The calculation of ESR line shifts of alkali-metal atoms (Li, Na, K, Rb) on helium nanodroplets 09:40-10:00 Thorsten Schumm Non-linear atom optics with Bose- Einstein condensates 10:00-10:20 Michele Sclafani Absolute single molecule detection efficiency for a superconducting nanowire 10:20-10:40 Christian Gruber Controlled coupling of quantum dots to nanowire plasmons 10:40-11:00 Franz Schmidt EEL-mapping of plasmon modes on a silver nano disk 11:00-11:30 Coffee break Thursday, 20 th September 2012, LS :30-15:50 Time Presenter Title 14:30-14:50 Laurin Ostermann Superradiance and cascaded decay of regular arrays of trapped atoms Rubidium atom Rydberg states perturbed 14:50-15:10 Florian Lackner by superfluid helium nan- odroplets 15:10-15:30 Carolina Matias Laser induced acoustic desorption of biomolecules 15:30-15:50 Coffee break 73

76 Thursday, 20 th September 2012, LS :50-18:00 Time Presenter Title Roughness and crystallinity contributions 15:50-16:10 Andreas Hohenau to surface-enhanced light- molecule interactions Fano resonances in photoionization 16:10-16:30 Andreas Kautsch spectra of chromium in helium nanodroplets 16:30-16:50 Katrin Tanzer Electron Interactions with Explosives 16:50-17:10 Johann Pototschnig Quantum chemical studies of Cr atoms on superfluid He nanodroplets 17:10-17:30 Laurentius Windholz Combination of Fourier transform- and laser spectroscopy to find unknown atomic energy levels 17:30-17:50 Bettina Gamper New energy levels of the neutral Pr atom in the IR region 74

77 Thu, 09:00-11:00, LS Thu, 09:00 Carbohydrate-Aromatic Complexes Investigated by Broadband Microwave Spectroscopy Thomas Betz 1,2, David Schmitz 1,2, Alvin Shubert 1,2, Melanie Schnell 1,2 1 Center for Free-Electron Laser Science, Notkestrasse 85, Hamburg, Germany 2 Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, Heidelberg, Germany A new broadband microwave spectrometer for the structural investigation of biologically relevant molecules in the gas phase is presented. The set up will be used to study the recognition of cyclic carbohydrates and aromatic molecules. This interaction is of significant importance in biological systems, for example, the recognition of cells by lectins. The carbohydrate partners will be represented by gluco-, galacto and fucopyranose, whereas benzene, indole, and tryptophan serve as model molecules for the aromatic recognition sites. The complexes will be formed by simultaneously seeding them into a supersonically expanding noble gas. The rotational spectra of these complexes will be recorded by employing the novel Chirped Pulse Fourier Transform Microwave (CPFTMW) spectroscopy technique1. This will allow the fast acquisition of the molecular response to microwave radiation in the range of 2 to 8 GHz and thus enables the comparison of different molecular Earlier investigations used infrared ion dip (IRID) vibrational spectroscopy to characterize the involved binding mechanism of these systems2. Measuring the rotational spectra will complement this work by allowing the direct investigation of the structure of the molecular complexes. This knowledge will deepen the understanding of the conformational properties and changes involved in the recognition process. Thu, 09:20 The calculation of ESR line shifts of alkali-metal atoms (Li, Na, K, Rb) on helium nanodroplets Andreas Hauser 1, Thomas Gruber 1, Wolfgang Ernst 1 1 Graz University of Technology, Petersgasse 16, 8010 Graz, Austria The line positions of electron spin resonance transitions (ESR) in alkali atoms are shifted for atoms attached to superfluid helium nanodroplets [1]. First attempts to describe the observed dependence of the hyperfine structure constant on the droplet size were based on a perturbational approach to the interaction between the He-cluster and the dopant, using the excited states of free alkali-metal atoms as basis sets for the matrix representation of the perturbation operator [2,3]. In an alternative approach we start from the analysis of the He-X dimers (X = Li, Na, K, Rb) with standard methods of quantum chemistry. Spin densities at the alkali atom, causing the isotropic part of the hyperfine interaction, can be calculated rather easily from most program packages at the Hartree-Fock (HF) level. Unfortunately, the weak van der Waals interactions between alkali atom and helium have to be treated at post-hf levels to obtain reasonable results. At least for Rb the inclusion of relativistic corrections is also indispensable. Furthermore, the experimental cluster sizes are out of range for any code based on molecular orbital theory. As a consequence, we try to reproduce the observed shifts by combining relativistic ab initio calculations for the He-X dimer systems with a simulation of full helium droplets based on density-functional theory. [1] Koch, M., Auböck, G., Callegari, C., Ernst, W. E., Phys. Rev. Lett. 103(3), (2009) [2] Koch, M., Callegari, C., Ernst, W. E., Mol. Phys. 108, (2010) [3] Callegari, C., Ancilotto, F., J. Phys. Chem. A 115, (2011) 75

78 Thu, 09:40 Non-linear atom optics with Bose-Einstein condensates Thorsten Schumm 1, Tarik Berrada 1, Jean-Francois Schaff 1, Sandrine Van Frank 1, Robert Bücker 1, Jörg Schmiedmayer 1 1 Technische Universität Wien - Atominstitut, Stadionallee 2, 1020 Wien, Austria Realizing building blocks of photon quantum optics for matter waves is a long-standing goal. We present an efficient source for twin-atom beams, in analogy to parametric down-conversion in non-linear optics. The source shows strong non-classical correlations in the population of the two beams, - 10dB below the classical limit. We also realized an integrated Mach-Zehnder interferometer for matter waves by combining a spatial beam splitter for BEC, a gravity-dependent phase-shifter and a recombined based on a pulsed Josephson tunnel junction. The intrinsic nonlinearity of the matter waves leads to number squeezing in the splitting process and to fundamental phase diffusion in the interferometer sequence. We will discuss performance limits towards matter wave metrology. Thu, 10:00 Absolute single molecule detection efficiency for a superconducting nanowire Michele Sclafani 1, Markus Arndt 1 1 University of Vienna, Boltzmanngasse 5, 1090 Wien, Austria We present a study of the absolute single-particle detection efficiency of a 100 nm wide 4 nm thick NbN meander for ions in the low kinetic energy regime (0.2-1 kev). We prove the capability of recording atomic and molecular ion signals in an energy range much lower than typically used in mass spectrometry and we show that up to a 100% detection efficiency can be achieved within our experimental setting. Superconducting nanowire devices have recently been proposed as an ideal alternative detection scheme for ionized [1,2] and neutral [3] particle beams. The detection process relies on the local suppression of superconductivity as the kinetic energy of the incoming particle is transferred to the electronic system of the wire. The impact of a molecule with the detector surface results in the rise of a resistive nanosecond voltage pulse when the wire is biased with a constant current. Finally we focus on the role of surface adsorbates in the detection process, which has remained neglected in all previous study so far, and we suggest new future strategies for optical spectroscopy on molecules, nanoparticles or helium nanodroplets. [1] M. Sclafani et al., Nanotechnology 23 (2012) [2] K. Suzuki et al., Rapid Communication Mass Spectrometry 24 (2010) [3] M. Marksteiner et al, Nanotechnology 20 (2009) 76

79 Thu, 10:20 Controlled coupling of quantum dots to nanowire plasmons Christian Gruber 1, Primoz Kusar 1, Andreas Hohenau 1, Joachim Krenn 1 1 University of Graz, Universitätsplatz 5, 8010 Graz The diameter of dielectric waveguides is limited by the wavelength of the guided light. In contrast, gold and silver nanowires can sustain propagating plasmon modes even for significantly smaller dimensions. Furthermore the strong field localization of the nanowire plasmon modes leads to a strong interaction with nearby quantum emitters such as quantum dots. We use electron beam lithography, first, to fabricate silver nanowires and, second, to position a few dots close to one nanowire end in a template-assisted process. Scanning a focused laser spot over the nanowire ends, we demonstrate both, the excitation of nanowire modes by quantum dots and the addressing of the same dots by plasmons. We use the fluorescence signals to quantify the quantum dots/plasmon coupling and show that part of the plasmon-induced dot fluorescence couples back to plasmonic modes. Thu, 10:40 EEL-mapping of plasmon modes on a silver nano disk Harald Ditlbacher 1, Franz Schmidt 2, Ulrich Hohenester 1, Andreas Hohenau 1, Ferdinand Hofer 2, Joachim Krenn 1 1 University of Graz, Universitätsplatz 5, 8010 Graz 2 Graz University of Technology, FELMI, Steyrergasse 17, 8010 Graz, Austria Localized surface plasmons are collective oscillations of the conducting electrons of metal nano structures coupled to an evanescent electromagnetic field. We study the plasmonic eigenmodes of a silver nano disk with laterally resolved electron energy loss spectroscopy (EELS) and observe beside the well-known dipolar, quadrupolar, hexapolar etc. modes a new type of modes which we name breathing modes analogous to acoustic vibrations. The surface charge distributions of dipolar and multipolar modes show radial node lines whereas the node lines of breathing modes are circles. These breathing modes are elementary plasmonic excitations of metal nano disks which have not been observed up to now as they do not couple to propagating light fields efficiently. This means these modes can hardly be detected by optical far field spectroscopy and they are therefore called dark modes. Nevertheless these modes affect the coupling of nano disks with molecular dipoles or other metal nano structures. Thu, 11:00-11:30: Coffee break 77

80 Thu, 14:30-18:00, LS Thu, 14:30 Superradiance and cascaded decay of regular arrays of trapped atoms Laurin Ostermann 1, Helmut Ritsch 1, Hashem Zoubi 1 1 University of Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria Lifetime and energy of collective optical excitations in regular arrays of atoms are significantly modified by dipole-dipole interaction. While the limiting cases of very closely positioned or infinite arrays of regularly spaced atoms can be approximated well by the Dicke superradiance or an exciton-based model, the situation of finite regular configurations is hard to access analytically. So far, most treatments are restricted to the lowest excitation manifold and a truncation of the interaction length We develop a general approach covering the complete decay cascade from the fully inverted to the ground state. We explicitly calculate all shifts and decay rates for the two generic cases of a 3-atom linear chain and an equilateral triangle and show their relation. In numerical calculations we show that despite fairly weak two-partite interactions, significant effects can build up in larger arrays through multi-particle interference. This changes the dephasing and decay properties in Ramsey experiments as well as the stability of superradiant lasers on narrow atomic lines as atomic clock transitions. Thu, 14:50 Rubidium atom Rydberg states perturbed by superfluid helium nanodroplets Florian Lackner 1, Günter Krois 1, Markus Koch 1, Wolfgang Ernst 1 1 Graz University of Technology, Petersgasse 16, 8010 Graz, Austria Spectroscopy of rubidium atoms on the surface of helium droplets (HeN) of different sizes gives information about the influence of a nanosized superfluid on rubidium Rydberg states. We present the excitation spectrum of the Rb-HeN system from the 5 2 D state manifold up to the ionization threshold, recorded by resonant three-photon-ionization time-of-flight spectroscopy [1, 2]. In addition to transitions from the 5 2 P 1/2 intermediate state into ns and nd states, transitions into np and nf states are observed. These transitions are allowed because of the reduced symmetry of the Rb-HeN system, which has a diatomic-like character. The observed transitions are broadened and shifted with respect to bare atom states, which is explained by a decreased quantum defect and a lowered ionization threshold within the scope of a Rydberg model. A set of six Rydberg series could be identified. Individual Rydberg states are observed with effective principle quantum numbers up to n 19 and l 3, for which the expectation value of the electron orbital radius is about 10 times larger than the droplet radius. [1] Lackner, F., Krois, G., Koch, M., Ernst, W.E., J. Phys. Chem. Lett. 3, (2012) [2] Lackner, F., Krois, G., Theisen, M., Koch, M., Ernst, W.E., Phys. Chem. Chem. Phys., 13, (2011) 78

81 Thu, 15:10 Laser induced acoustic desorption of biomolecules Carolina Matias 1, Johannes Postler 1, David Gschliesser 1, Marcelo Goulart 1, Paul Scheier 1, Stephan Denifl 1 1 University of Innsbruck, Technikerstrasse 25/3, 6020 Innsbruck, Austria When high energy radiation interact with living cells it creates, along the ionization track, a set of secondary species. Low energy (<20eV) electrons are the most abundant ones and can induce strand breaks in DNA. The investigation of the influence of secondary particles in biomolecular systems, whether in the gas phase or in condensed phase, is a rich research area which applies both to gain fundamental knowledge and application-oriented results. Previous mass spectrometry experiments with low energy electrons dealt with small DNA building blocks and protein in the gas phase. In this work we perform free electron attachment studies to more complex systems like nucleotides. Typical experimental setups use ovens in which a sample of a certain biomolecule is heated and thereby evaporated. With the increasing size of the molecules there is a high risk of thermal decomposition. The advantage of using laser induced acoustic desorption is that one can prevent thermal decomposition and evaporate large molecules unbroken. The sample is applied as a very thin film on a thin metal foil, and then the foil is irradiated at the backside with a pulsed laser. The laser pulses will create an acoustic wave, which propagates through the metal and desorbs the sample from the surface. Such a technique enables us to get large DNA building blocks or proteins into the gas-phase and makes it possible to investigate pure electron molecule interactions. This gives us important basic insight into the reactions happening in radiation damage. Thu, 15:30-15:50: Coffee break 79

82 Thu, 15:50-18:00, LS Thu, 15:50 Roughness and crystallinity contributions to surface-enhanced light-molecule interactions Andreas Hohenau 1, Joachim Krenn 1, Jean-Claude Tinguley 1 1 University of Graz, Universitätsplatz 5, 8010 Graz, Austria Noble metal nanoparticles show specific optical properties due to the excitation of localized surface plasmons that give rise to surface enhanced absorption, fluorescence or Raman scattering. The nanoparticle geometry the dielectric properties of the metal and nanoscale surface roughness play an important role for surface enhanced effects, however they not yet well understood for lithographically fabricated nanoparticles. We approach this question by analyzing the optical characteristics of lithographically fabricated nanoparticles with different crystalinity and roughness parameters. They are varied by thermal annealing and a thin gold film is applied as a model system to retrieve modifications in the dielectric function. We investigate, on one hand, extinction spectra of metal nanoparticles that reflect the far-field properties of the plasmonic excitation and, on the other hand, surface-enhanced Raman spectra that serve as a near-field probe. Our results provide improved insight into localized surface plasmons and their application in light-molecule interactions. Thu, 16:10 Fano resonances in photoionization spectra of chromium in helium nanodroplets Andreas Kautsch 1, Matthias Hasewend 1, Martin Ratschek 1, Markus Koch 1, Wolfgang Ernst 1 1 Graz University of Technology, Petersgasse 16, 8010 Graz, Austria Ultracold He nanodroplets (He N ) at 0.4 K serve as ideal matrix to isolate and analyze single atoms with supporting effects from the interaction with the surrounding He [1]. Resonance ionization mass spectroscopy (RIMS) is a versatile technique to selectively excite and detect atoms. We combined these methods and carried out resonant two-photon ionization (R2PI) measurements on Cr atoms in He N in the wavelength range from 350 to 361 nm ( cm 1 ). Possible pathways leading to ionization include a strong first step y 7 P a 7 S transition happening inside the droplet. This results in a broadening and a blue shift of about 7 nm enabling the possibility to obtain detailed information about the perturbation upon electronic excitation of the Cr atom in He N [2]. Subsequently, the Cr atom leaves the droplet and simultaneously relaxes into lower lying states, which are spin and parity forbidden transitions. With a second photon of the same colour the ionization is accomplished through either continuum or autoionization states. We characterized Fano type resonances in terms of laser fluence saturation to get further insight into the various processes. [1] Ratschek, M., Koch, M., and Ernst, W. E., J. Chem. Phys. 136, (2012). [2] Callegari, C., and Ernst, W. E., in Handbook of High-Resolution Spectroscopy, eds. Quack, M., and Merkt, F., John Wiley & Sons, Chichester,

83 Thu, 16:30 Electron Interactions with Explosives Katrin Tanzer 1, Benjamin Puschnigg 1, Violaine Vizcaino 1, Stephan Denifl 1, Paul Scheier 1 1 University of Innsbruck, Technikerstrasse 25/3, 6020 Innsbruck, Austria In recent years a considerable interest in improving methods for the detection of explosives has arisen since the threat of attacks on planes and high risk buildings has grown steadily. Two methods for the detection working with electron-molecule collisions and mass spectrometry are presented and compared. Electron attachment of low energy electrons often leads to dissociation. In the case of explosive substances, every single explosive has a rich characteristic fragmentation pattern. This has been measured in our group for the explosives RDX and PETN amongst others. Together with the resonance profiles of the fragments even the distinction between isomers is possible, as shown for the three DNB isomers. Another possible technique for the detection of explosives is electron ionization where cations are formed by impact of electrons of about 70 ev. Usually considered a hard ionization method, electron ionization also leads to rich fragmentation patterns. Together with the ion efficiency curves and especially the appearance energy they form a unique fingerprint for every explosive. Mass spectra and appearance energies have been determined for several explosives including RDX, PETN and TNB. Considerable differences have been found even for the DNB isomers. Thu, 16:50 Quantum chemical studies of Cr atoms on superfluid He nanodroplets Johann Pototschnig 1, Martin Ratschek 1, Andreas Hauser 1, Markus Koch 1, Wolfgang Ernst 1 1 Graz University of Technology, Petersgasse 16, 8010 Graz, Austria He nanodroplets (HeN) provide a superfluid quantum matrix at 0.4 K. Single atoms or molecules doped on HeN can be investigated and used to synthesize nanostructures that may be deposited on surfaces [1]. The location of the dopant on HeN affects the amount of spectroscopic perturbation and the formation of nanostructures on HeN. Cr has outstanding magnetic properties due to the septet ground state. In combination with He, a weak van der Waals molecule is formed which is challenging to describe theoretically. We calculated the Cr-He pair potential curve with different post Hartree-Fock methods. CCSD(T), CI, and multireference perturbation theory (RS) were applied, all including relativistic Douglas-Kroll corrections. After counterpoise correction we extrapolated to the basis set limit. The pair potential is applied to calculate the so-called Ancilotto parameter [2] and to DFT calculations for the He density [3]. Both methods indicate that Cr resides inside HeN. Our group also investigates the Cr-HeN complex experimentally by means of mass and laser spectroscopy. First experimental results will be reported besides the theoretical calculations. [1] Loginov E., Gomez L. F., Vilesov A. F., J. Phys. Chem. A 115, 7199 (2011) [2] Ancilotto F., Lerner P. B., Cole M. W., J. Low Temp. Phys. 101, 1123 (1995) [3] Dalfovo F., Lastri A., Pricaupenko L., Stringari S., Treiner J., Phys. Rev. B 52, 1193 (1995) 81

84 Thu, 17:10 Combination of Fourier transform- and laser spectroscopy to find unknown atomic energy levels Laurentius Windholz 1 1 Graz University of Technology, Petersgasse 16, 8010 Graz, Austria Opposite to common assumptions, still not all energy levels of chemical elements are known. Thus it is quite often not possible to explain even strong spectral lines as transitions between certain energy levels. For elements which nuclei possess a spin quantum number I>0, the hyperfine structure constants can be used additional as finger print for a level. The hyperfine pattern predicted for a certain level combination then can be compared with the pattern in a highly resolved Fourier transform spectrum, and the line can be classified. Lines which can not be explained as combinations of known levels can be excited by laser light. The information gained from the observed hyperfine pattern (angular momenta J of the electron shell and hyperfine constants) together with excitation and fluorescence wavelengths can be used to find the properties of the up to now unknown energy levels. The existence of such level can be verified by the Fourier spectrum since such level must explain other lines with respect to hyperfine pattern and center of gravity wave number. A computer program which allows to handle data bases for spectral lines and levels of an element is presented. Thu, 17:30 New energy levels of the neutral Pr atom in the IR region Bettina Gamper 1, Imran Siddiqui 1, Uddin Zaheer 2, Laurentius Windholz 1 1 Graz University of Technology, Petersgasse 16, 8010 Graz, Austria 2 Yanbu University College, Yanbu Industrial City , P.O.box 31387, Kingdom of Saudi Arabia With the help of the new Fourier transform spectra (FTS) of Pr [1] and with laser-induced fluorescence (LIF) spectroscopy it was possible to find a big amount of new energy levels in the past year [2], [3] and [4]. In the IR region we still do not have a suitable laser to perform LIF spectroscopy. Nevertheless for some well-resolved lines, we were able to investigate their structure and hence to introduce 21 new energy levels of the neutral Pr atom. All of them have odd parity and their J-value differs from 1/2 to 19/2. The appearance of the line in the FTS, the small components have to be resolved, gives us the J-value and the hf constants could be determined by fitting the hf pattern of the investigated line. All of the newly presented atomic levels explain a lot of so far not classified lines. As an example we discuss the line with the cg wavelength and the so determined level with an energy of (5) cm 1, a J-value of 15/2 and a hf constant A of 959(9) Mhz (the hf constant B is assumed to be zero). [1] B.Gamper et al.; J. Phys. B. 44, (2011) [2] K.Shamim et al.; Eur. Phys. J. D 64, (2011) [3] T.I.Syed et al.; Phys. Scr. 84, (2011) [4] Z.Uddin et al.; Journal of Physical Science and Application, in press 82

85 8 Solid State Physics (FKP) & Research with Neutron and Synchrotron Radiation (NESY) HS Solid State Physics and Research with Neutrons and Synchrotron Radiation Festkörperphysik: Physik an Neutronen- und Synchrotronstrahlungsquellen Gottfried Strasser, Ernst Bauer, Thursday, 20 th September 2012, HS :00-11:00 Time Presenter Title 09:00-09:30 Armando Rastelli Electro-elastic control of excitons in single quantum dots 09:30-09:45 Roland Brunner Imaging of classical trajectories and quantum mechanical states in open quantum dots 09:45-10:00 Benedetta Marmiroli What can be obtained by bringing together small angle X-ray scattering and deep X-ray lithography? 10:00-10:15 Rainer Lechner Core/shell profile of nanocrystals determined by anomalous SAXS Supercrystals formed by monodisperse 10:15-10:30 Dominik Kriegner nanocrystals investigated by X-ray diffraction 10:30-10:45 Mario Keplinger Investigations of radial and axial heterostructured nanowires using x-ray diffraction 10:45-11:00 Walter Pötz Quantum Dot Cavity Spin Entanglement at a Distance - A Theoretical Analysis 11:00-11:30 Coffee break 83

86 Thursday, 20 th September 2012, HS :30-15:30 Time Presenter Title 14:30-14:45 Martin Kaltenbrunner Anton Paar-Prize 14:45-15:00 Christian Ertler 15:00-15:15 Benjamin Stickler 15:15-15:30 René Hammer 15:30-15:50 Coffee break Power Supply, Generation and Storage in Stretchable Electronics Disorder effects on resonant hole tunneling transport in (Ga,Mn)As/GaAs heterostructures Prediction of room-temperature spin filtering in (CrAs/GaAs) heterostructures Dynamics of Dirac Fermions on Surfaces of Topological Insulators Thursday, 20 th September 2012, HS :50-17:35 Time Presenter Title 15:50-16:05 Peter Reininger Enhancing the detectivity of photonic crystal photodetectors by quality factor tuning 16:05-16:20 Benedikt Schwarz Optimization of intersubband devices for dual-color emission, absorption and detection 16:20-16:35 Lukas Burgstaller Substrate emitting ring cavity quantum cascade lasers 16:35-16:50 Ronald Meisels Studies on the Coupling of Dielectric and Plasmonic Waveguides using FEM and FDTD Simulations 16:50-17:20 Michael Reissner Superconducting properties of multifilamentary MgB2 wires Combining SQUID magnetometry with in-situ cyclic voltammetry to 17:20-17:35 Stefan Topolovec study the electrochemical charginginduced variation of the magnetic moment of γ-fe 2 O 3 nanoparticles 17:35-17:50 Thomas Franosch Transport beyond Brownian Motion Colored noise 17:50 FKP & NESY member meeting 84

87 Friday, 21 st September 2012, HS :00-11:00 Time Presenter Title Comparison of MOS and Schottkybarrier 09:00-09:15 Mattia Capriotti structure in AlGaN/GaN HEMTs 09:15-09:30 Alfred Neuhold Interface Morphology of an Orthogonal Soluble Polymer Transistor Temperature Induced Wetting 09:30-09:45 Michael Dohr and Dewetting Effects of Dioctylbenzothieno-benzothiophene on Silicon Oxide Surfaces 09:45-10:00 David Geist Metastable structures and phases of intermetallics produced by severe plastic deformation 10:00-10:30 Benedetta Marmiroli Quantitative analysis of liquid jets breakup with SAXS Direct measurements of reversible 10:30-10:45 Martin Luckabauer free-volume formation in bulk Zr 56 Al 7 Cu 24 Ni 10 Co 3 glass below the glass transition temperature Positron annihilation spectroscopy 10:45-11:00 Peter Parz on LiCoO2-electrodes with different lithium content 11:00-11:30 Coffee break Friday, 21 th September 2012, HS :30-12:45 Time Presenter Title 11:30-12:00 Heinz Amenitsch Self Assembly of Mesoporous Materials in the Gas-Phase: An in situ SAD Study Mechanical properties of carbon 12:00-12:15 Markus Hartmann nanostructures investigated by Monte Carlo simulations 12:15-12:30 Maria Daghofer Topologically nontrivial and nearly flat bands in multi-orbital models 12:30-12:45 Jörn Venderbos Itinerant electrons in a 2-dimensional spin-ice system: Kondo-Lattice model on the checkerboard lattice Thu, 09:00-11:00, HS

88 Thu, 09:00, Invited Electro-elastic control of excitons in single quantum dots Armando Rastelli 1,2, Rinaldo Trotta 1,2, Eugenio Zallo 2, Paola Atkinson 2, Oliver Schmidt 2 1 Johannes Kepler Universität Linz, Altenberger Straße 69, 4040 Linz, Austria 2 IFW Dresden, Helmholtzstrasse 20, Dresden, Germany Optically active semiconductor quantum dots (QDs) can be made as epitaxial nanoinclusions of a low energy bandgap material in a matrix with larger energy bandgap. Many recent experiments have demonstrated that these QDs are excellent quantum emitters, which can be used as sources of triggered single photons, indistinguishable photons and polarization entangled photon pairs. The structural properties of self-assembled QDs are affected by unavoidable fluctuations, which make it difficult to obtain QDs with electronic and optical properties which meet the - sometimes very stringent - requirements for their use in advanced quantum optics experiments. Post-growth techniques are therefore needed to fine-tune the optical properties of QDs. In this talk we will discuss QD-based devices in which the semiconductor structures are integrated on top of piezoelectric actuators made of PMN-PT. This combination allows us to study in detail the effects produced by variable strains (up to about 0.3%) on the excitonic emission of single QDs and to manipulate reversibly and in a broad range the excitonic emission of single dots. In particular, by using diodelike nanomembranes we can simultaneously use elastic deformation and electric fields to control the electronic structure of QDs. This allows us e.g. to achieve independent control of emission energy and charge-state of a QD and to realize wavelength-tunable single-qd light-emitting diodes. Possible future extensions and applications of this technology will be discussed. Thu, 09:30 Imaging of classical trajectories and quantum mechanical states in open quantum dots Roland Brunner 1, Ronald Meisels 1, Nobuyuki Aoki 2, Yuichi Ochiai 2, Richard Akis 3, Adam Burke 4, David Ferry 3 1 Montanuniversität Leoben, Franz-Josef-Straße 18, 8700 Leoben, Austria 2 Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba , Japan 3 Arizona State University, P.O. Box 9309, Tempe, AZ , USA 4 University of New South Wales, Sydney, NSW 2052, Australia In this work, we show classical and quantum mechanical simulations as well as scanning gate microscopy (SGM) to probe the ballistic motion of electrons within an open GaAs/AlGaAs quantum dot (QD). SGM, in combination with transport measurements, can provide an interesting tool to image the motion of electrons in quantum systems [1]. Recently, it has been theoretically argued for an open QD that, due to the induced perturbation of the SGM tip the imaging of the original open QD states is ambiguous [2]. However in this theoretical approach a system with a hard wall potential was used. Our model calculations are performed by using a soft-wall as opposed to a hard-wall potential. This potential is obtained from fully self-consistent calculations. From the classical and quantum mechanical simulations we are able to extract the electron trajectories and probability density, respectively. Conductance maps are recorded by using SGM. Here, a biased tip in a cryogenic SGM is scanned over the open quantum dot while a magnetic field is applied. We show that, for specific magnetic fields, the measured conductance images resemble the classical transmitted and backscattered trajectories and their quantum mechanical analogue [3]. The demonstrated direct imaging technique is essential for the fundamental understanding of wave function scarring and quantum decoherence theory. [1] M. A. Topinka et al., Science 289, 2323 (2000). [2] M. Mendoza and P.A. Schulz, Phys. Rev. B 71, (2005). [3] N. Aoki, R. Brunner et al., Phys. Rev. Lett. 108, (2012). 86

89 Thu, 09:45 What can be obtained by bringing together small angle X-ray scattering and deep X-ray lithography? Benedetta Marmiroli 1, Fernando Cacho-Nerin 1, Barbara Sartori 1, Paolo Falcaro 2, Luca Malfatti 3, Marco Faustini 4, Stefano Costacurta 5, David Grosso 4, Plinio Innocenzi 3, Heinz Amenitsch 1 1 Österreichische Akademie der Wissenschaft, Schmiedlstrasse 6, 8042 Graz, Austria 2 CSIRO, Gate 5 Normanby Rd, Clayton VIC 3168, Australia 3 LMNT, Universitá di Sassari, Palazzo Pou Salit, Piazza Duomo, Alghero (SS), Italy 4 Universit Pierre et Marie Curie, 4 place Jussieu, Tour 54, E.5 Couloir 54-55, Paris Cedex 05, France 5 CIVEN, Via delle Industrie 5, Torre Hammon, Venezia-Marghera, Italy Micro-nanotechnology has melted away the borders between material science and biology. In fact, the miniaturization of chemical and biological assays, promoted by micro-nanofluidics, requires both a careful selection of the fabrication methods and the development of tailored materials for the specific applications. As a consequence, interdisciplinarity is becoming fundamental also in the combination of microfabrication and characterization techniques both aimed at the construction of new devices and at the development of novel materials for chemistry and biology applications. In this communication, we want to underline the advantages obtainable by combining two techniques: Deep X-ray Lithography (DXRL) for microfabrication and Small and Wide Angle X-ray Scattering (SAXS/WAXS) for investigation. On one hand DXRL makes it possible for SAXS to improve time resolution and create new sample environments. On the other hand SAXS permits the investigation of the nanostructural morphology of the microstructures fabricated by DXRL in order to tune the morphology for specific applications like nanosensors and biosensors or to determine the effect of irradiation on new materials. Examples will be presented to highlight both. First, microdevices fabricated for time resolved experiments of fast biological and chemical reactions, or for the study of the effect of confinement on crystal growth will be discussed. Then, the combination of bottom-up and top-down approaches for the development of new functionalized materials for which characterization with SAXS/WAXS is fundamental will be described. Thu, 10:00 Core/shell profile of nanocrystals determined by anomalous SAXS Rainer Lechner 1, Gerhard Fritz-Popovski 1, Maksym Yarema 2, Wolfgang Heiss 3, Oskar Paris 1 1 Montanuniversität Leoben, Franz-Josef-Straße 18, 8700 Leoben, Austria 2 Swiss Federal Laboratories for Material Science and Technology, Überlandstrasse 129, 8600 Dübendorf, Switzerland 3 Johannes Kepler Universität Linz, Altenberger Straße 69, 4040 Linz, Austria The infrared emission of lead chalcogenide nanocrystals (NCs) can be drastically increased stabilising the core with a hard protective shell [1]. In contrast to a shell growth on top of a core [2], we investigate in this study the CdS-shell growth on PbS NCs driven by Cd for Pb cation exchange [1]. We perform anomalous SAXS experiments at the synchrotrons HZB-BessyII and ESRF. Tuning the x-ray energy below the Pb-edge allows to record ASAXS spectra, where the contribution of Pb to the scattering signal is varied. This allows resolving the total electron density and the Pb-atom density inside the core/shell NCs independently. We derive the following results: During the exchange process applied to PbS spheres, the core shrinks, the CdS shell thickness increases, while the outer diameter as well as the size distribution remains constant. The CdS shell thickness ranges from 0.9 nm for 10 nm large PbS NCs to even 2 nm for 5 nm small NCs. The final shell thickness scales with 1/D of the sphere diameter, related to an increased surface to volume ratio for the smaller NCs. For the thin CdS shells we found no reaming Pb within the shell, whereas for thick shells we detect 2 Pb atoms per cubic-nm within the shell. [1] H. Zhao, M. Chaker, N. Wu and D. Ma, J. Mater. Chem., 21, (2011) [2] M. Yarema, S. Pichler, M. Sytnyk, R. Seyrkammer, R.T. Lechner, et al., ACS Nano 5, (2011) 87

90 Thu, 10:15 Supercrystals formed by monodisperse nanocrystals investigated by X-ray diffraction Dominik Kriegner 1, Maksym Yarema 2, Tanja Etzelstorfer 1, Mario Keplinger 1, Mykhailo Sytnyk 1, Wolfgang Heiss 1, Maksym Kovalenko 2, Julian Stangl 1 1 Johannes Kepler Universität Linz, Altenberger Straße 69, 4040 Linz, Austria 2 ETH Zurich, Department of Chemistry and Applied Biosciences, Wolfgang-Pauli-Str. 10, 8093 Zurich, Switzerland Colloidal nanocrystals are subject of intense research because of their high potential for applications in electronic, magnetic and optical devices. Furthermore they show a high tendency to form ordered two and three-dimensional superstructures ( supercrystals ). The precise ordering in those supercrystals affects the electronic coupling between the individual nanocrystals and it was shown to lead to new collective properties. These properties are related to, and hence strongly affected by the degree of ordering obtained in the supercrystals, which in turn depends on nanocrystal size, the capping ligands and chemical species of chosen nanocrystals, as well as the monodispersity of the used nanocrystal batch. Thus, quantifying the degree of ordering and perfectness of supercrystals is of major interest, in order to enable a quantitative correlation between ordering and the ordering-dependent physical properties. To judge the quality of self-assembly obtained in 3D nanocrystal superlattices, we use X-ray diffraction, applied to individual supercrystallites. The supercrystals have typical sizes of 10µm, whereas the nanocrystals are below 20nm in diameter. While for two-dimensional arrays of self-assembled nanocrystals, ordering can be quantified by inspecting electron microscope images, for faceted 3D nanocrystal supercrystals, much more efforts have to be undertaken to obtain characteristic numbers, which allow to assess the degree of ordering obtained by the self assembly process. 3D reciprocal space maps are recorded at a synchrotron source using a micrometer sized X-ray beam, from which we find that the quality of ordering is strongly anisotropic. Thu, 10:30 Investigations of radial and axial heterostructured nanowires using x-ray diffraction Mario Keplinger 1, Bernhard Mandl 1, Maria Messing 2, Dominik Kriegner 1, Julian Stangl 1, Vaclav Holy 3 1 Johannes Kepler Universität Linz, Altenberger Straße 69, 4040 Linz, Austria 2 Lund University, S Lund, Sweden 3 Charles University, Ke Karlovu 5, Prague, Czech Republic The unique electronic, optical, and structural properties of semiconductor nanowires (NWs) allow the fabrication of suitable building blocks for future nanoelectronic and nanophotonic devices. Such applications require complex NW structures with either axial or radial NW heterostructures to provide for carrier confinement and/or for the waveguiding of light. Therefore we investigated samples with InAs1-x Px heterostructured NWs. These heterostructured NWs consist of an InAs core with an InAs1-x Px shell and heterosegment on top. The structural and chemical properties were investigated depending on the growth conditions. For one series with varied arsine/phosphine flow, and one with varied growth temperature, the average chemical composition, i.e. the phosphorus content, the strain, and the dimensions were deduced using a combination of scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy, and X-ray diffraction (XRD). The XRD data evaluation was done by calculating the strain distribution in a NW using finite element simulations. From this simulations the diffusely scattered intensity distribution was then calculated for a NW ensemble with a simple Monte Carlo method to account for statistical variations of the NW properties. A dependency of the P to As ratio in the hetero-segment on the arsine/phosphine precursor ratio was found with a proportionality factor of 0.75, whereas the variation of the growth temperature gave no variation of the chemical composition, but a change of the NWs aspect ratio. 88

91 Thu, 10:45 Quantum Dot Cavity Spin Entanglement at a Distance - A Theoretical Analysis Walter Pötz 1 1 University of Graz, Universitätsplatz 5, 8010 Graz, Austria Measurement of conditional Faraday rotation has recently been proposed for entanglement generation at a distance.[1-3] In this talk we present a theoretical analysis of entanglement formation at a distance between two electron spins, each sitting in one of two distant quantum dot cavities. Entanglement is induced by measuring the conditional Faraday rotation of a non resonant laser pulse which has propagated through the two cavities. The basis for this scheme are two identical scatterers, such as an atom or a quantum dot, where each has two initial states, whereby only one of them is optically active, for example, by dipole selection rules. Here we investigate one sided cavities which avoid unintentional measurement in the reflected beam.[4] Frequency sweet spots are identified for which, in spite of dissipative action, good fidelity entanglement generation should be possible. We also predict that monitoring of the Faraday rotation allows the detection of single spin flips, similar to single non demolition photo-emission monitoring in atom quantum cavity systems.[5] The possibility of studying entanglement death and revival in this system is discussed. [1] T. D. Ladd et al., New Journal of Physics 8, 184 (2006). [2] J. Grond, W. Pötz, and A. Imamoglu, Phys. Rev. B 77, (2008). [3] W. Pötz, Physical Review B 77, (2008). [4] W. Pötz, J. Comp. Electr., Volume 8 (1), (2009). [5] M. Brune et al., Phys. Rev. Lett. 101, (2008). Thu, 11:00-11:30: Coffee break 89

92 Thu, 14:30-15:30, HS Thu, 14:30, Anton Paar-Prize Winner Power Supply, Generation and Storage in Stretchable Electronics Martin Kaltenbrunner 1 1 Johannes Kepler Universität Linz, Altenberger Straße 69, 4040 Linz, Austria Talk of the Anton Paar-Prize Winner. Thu, 14:45 Disorder effects on resonant hole tunneling transport in (Ga,Mn)As/GaAs heterostructures Christian Ertler 1, Walter Pötz 1 1 University of Graz, Universitätsplatz 5, 8010 Graz, Austria Recent experiments on heterostructures comprising (Ga,Mn)As quantum wells [1] have evoked strong debates about the near absence of ferromagnetic order observed in these structures [2]. Here, we present a theoretical examination of these experimental results, studying the self-consistent interplay between ferromagnetic order, structural defects, and the hole tunnel current [3]. The hole band structure is described by a four band Kohn-Luttinger Hamiltonian and the transport characteristics are obtained within the non-equilibrium Green s function approach. We show that disorder has a strong influence on the current-voltage (IV) characteristics in efficiently reducing or even washing out negative differential conductance, as found in experiment. The hole density in the quantum well is established through (tunneling) transport from the p-doped GaAs leads. We find that, for the Be lead doping levels used in experiment, the resulting spin density polarization in the quantum well only produces an exchange splitting of the order of a few mev, comparable to the experimental findings. We predict that the ferromagnetic order in the (Ga,Mn)As quantum well tends to be completely destroyed under resonance bias condition. This should lead to a characteristic bias-dependence of the spin-polarization (bias anomaly) of the tunnel current, available to experimental detection. Supported by FWF P21289-N16. [1] S. Ohya, K. Takata and M. Tanaka, Nature Physics, 7, 342 (2011). [2] T. Dietl and D. Sztenkiel, arxiv: (2011). [3] C. Ertler and W. Pötz, Phys. Rev. B 84, (2011). 90

93 Thu, 15:00 Prediction of room-temperature spin filtering in (CrAs/GaAs) heterostructures Benjamin Stickler 1, Christian Ertler 1, Liviu Chioncel 2, Enrico Arrigoni 3, Walter Pötz 1 1 University of Graz, Universitätsplatz 5, 8010 Graz, Austria 2 Zentrum für Elektronische Korrelationen und Magnetismus, Universität Augsburg, Augsburg, Germany 3 Graz University of Technology, Petersgasse 16, 8010 Graz, Austria Half-metallic materials are of profound interest in spintronic applications since, by definition, their density of states at the Fermi energy is 100 % spin polarized. Recent experiments as well as ab-initio calculations suggest that CrAs, grown epitaxially in the fcc structure on top of GaAs, is such a halfmetallic ferromagnet with a Curie temperature well above room temperature [1,2]. We present theoretical results, which suggest that spin-filtering in CrAs/GaAs heterostructures at room temperature could indeed be realized. Our theoretical approach consists of three crucial steps: In a first step we determine the spin-polarized band structure of lattice matched fcc bulk CrAs and a (GaAs) 6 /(CrAs) 6 supercell. From these calculations we determine the band offset between the two materials as well as their bulk electronic structure. Within the second step we map the electronic structure of the bulk materials onto an effective 20-orbtial sp3d5s* nearest neighbor tight-binding (TB) model. In a third step we calculate current-voltage (IV) characteristics for heterostructures consisting of thin layers of CrAs embedded in a GaAs environment. The characteristics are determined within the non-equilibrium Green s function formalism. The resulting IV characteristics provide an experimentally accessible fingerprint of the electronic structure of fcc CrAs and indicate that room temperature spin filtering should indeed be realizable in such systems. (Supported by FWF P N16) [1] H. Akinaga, T. Manago, M. Shirai, Jpn. J. Appl. Phys., 39 (2000) [2] L. Chioncel et al. Phys. Rev. B, 83 (2011) Thu, 15:15 Dynamics of Dirac Fermions on Surfaces of Topological Insulators René Hammer 1, Christian Ertler 1, Walter Pötz 1 1 University of Graz, Universitätsplatz 5, 8010 Graz, Austria Topologically protected states may form at the surface of insulators with strong spin-orbit interaction[1]. Near the Kramer s points, the electronic states can be mapped upon a mass-less 2+1 Dirac fermion Hamiltonian and the effective-mass term can be controlled by an external magnetic field (breaking time-reversal symmetry). In this talk we present some of our recent results from a theoretical study of the dynamics of 1+1 and 2+1 Dirac fermions simulated numerically on a lattice. For 1+1 dimensions we present and demonstrate perfect absorbing boundary conditions using algorithms which avoid fermion doubling. In 2+1 dimensions we present absorbing boundary conditions obtained from an imaginary potential in the asymptotic space regions[2]. For numerical examples we study several physical processes: wave packet propagation at a simple Klein step, a quantum interferometer[2], and a superlens realization. [1] M. Z. Hasan and C. L. Kane, Rev. Mod. Phys. 82, 3045 (2010). [2] Ren Hammer, Christian Ertler, and Walter Pötz, arxiv: (2012) 91

94 Thu, 15:30-15:50: Coffee break Thu, 15:50-17:35, HS Thu, 15:50 Enhancing the detectivity of photonic crystal photodetectors by quality factor tuning Peter Reininger 1, Stefan Kalchmair 1, Roman Gansch 1, Aaron Maxwell Andrews 1, Hermann Detz 1, Tobias Zederbauer 1, Werner Schrenk 1, Gottfried Strasser 1 1 Vienna University of Technology, Floragasse 7, 1040 Vienna, Austria An important figure of merit of photodetectors is the detectivity. A quantum well infrared photodetector (QWIP) has an inherent limitation to the detectivity at higher temperatures (above TBLIP), because an increase of the responsivity by higher doping increases the noise by about the same amount. Therefore, both effects cancel each other out. Another approach is to use a photonic crystal slab (PCS) as a resonant cavity in conjunction with a reduced doping concentration in the quantum wells. We have shown, that the noise due to dark current can be reduced significantly, while the high lifetime of photons in the PCS maintains a high responsivity. We present a PCS fabricated from a QWIP material. Under Globar illumination, an increase of the maximum operation temperature from around 110K for a standard QWIP up to 200K for a low-doped PCS-QWIP with a peak absorption at λ = 8µm was observed. The combined effect of responsivity enhancement and dark current noise reduction results in an enhanced specific detectivity D* of up to 20 times. Thu, 16:05 Optimization of intersubband devices for dual-color emission, absorption and detection Benedikt Schwarz 1, Peter Reininger 1, Oskar Baumgartner 2, Zlatan Stanohevic 2, Hans Kosina 2, Gottfried Strasser 1 1 Vienna University of Technology, Floragasse 7, 1040 Vienna, Austria 2 Vienna University of Technology, Gußhausstrasse 27-29, 1040 Vienna, Austria Quantum cascade lasers (QCL) and detectors (QCD) are powerful mid-infrared devices. A QCL can also act as a photovoltaic detector, but normally at a significant lower wavelength than the laser. Thus quantum cascade structures are commonly designed as either lasers or detectors. We have designed a dual wavelength quantum cascade structure that can act as coherent source and photovoltaic detector at the same wavelength. As a step towards monolithic integrated photonic circuits, such multipurpose devices open up new possibilities for on-chip applications by emitting, absorbing and detecting light on the same chip. Apart from typical real world applications, like chemical sensing, spectroscopy and free space communication, it can be used to study optical couplings, interaction of light and matter, as well as non-linear effects within one chip. Due to its complexity, such a device structure requires a careful quantum design to maximize performance, while matching the designed wavelength for both laser and detector operation. When a certain voltage is applied, the structure acts as a dual wavelength laser. At zero bias it acts as a photovoltaic detector or a. In this case, the injector states form a phonon ladder leading to a built-in electric field. After optical excitation the electrons can scatter via this phonon ladder to the lower level of the next period. The design fine tuning is done by an optimization algorithm based on a high efficient semi-classical Monte-Carlo quantum cascade simulator. 92

95 Thu, 16:20 Substrate emitting ring cavity quantum cascade lasers Lukas Burgstaller 1, Clemens Schwarzer 1, Sang Il Ahn 1, Werner Schrenk 1, William Charles 2, Claire Gmachl 3, Strasser Gottfried 1 1 Vienna University of Technology, Floragasse 7, 1040 Vienna, Austria 2 Phononic Devices, Inc., Raleigh, North Carolina 27606, USA 3 Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA Quantum cascade lasers (QCLs) evolved to versatile and reliable light sources in the midinfrared (MIR) and terahertz (THz) spectral region. Recently, our group reported the ring cavity surface emitting QCL. The ring-type resonator, in combination with a second order distributed feedback grating (DFB) grating provides collimated beam profiles, along with robust single-mode emission. DFB gratings also diffract a certain amount of light towards the substrate. Within this work we perform investigations regarding the emission direction of ring-qcls. A variation of the grating duty cycle (GDC) is performed to obtain an enhancement of the substrate emitted optical power. All devices showed single-mode operation at frequencies around 1296 /cm. Peak optical power values of 16.6 mw for surface emission and 9.25 mw for substrate emission were measured. When the GDC is not optimized for surface emission (around 70% ), a far greater amount of light is emitted through the substrate. Maximum values for substrate emission are found for GDCs around 56%. This agrees very well with the simulation results. When accounting for the substrate absorption and the transmission coefficient at the substrate-air interface, it is demonstrated that the whispering gallery modes are predominantly diffracted towards the substrate. The authors acknowledge the support by the Austrian projects IR-ON (FWF: F2503-N17) and PLATON, the GMe and MIRTHE (NSF-ERC, EEC ). Thu, 16:35 Studies on the Coupling of Dielectric and Plasmonic Waveguides using FEM and FDTD Simulations Ronald Meisels 1, Markus Humer 2, Oleksandr Glushko 1, Roland Brunner 1, Thomas Fromherz 2 1 Montanuniversität Leoben, Franz-Josef-Straße 18, 8700 Leoben, Austria 2 Johannes Kepler Universität Linz, Altenberger Straße 69, 4040 Linz, Austria An important goal for optimizing the transfer of light into and out of silicon based waveguides for integrated optics is the reduction of the footprint of the device on a chip. Therefore a hybrid dielectric/plasmonic coupling structure [1] is studied. The plasmonic modes of a gold strip of subskin-depth thickness couple symmetrically and asymmetrically to form long range (LRSPP) and short range surface plasmon polaritons (SRSPP) respectively. The dimensions of the gold strip are tuned to support effective-index-matching of the SRSPP mode and the fundamental mode of a SoI (Silicon on Insulator) based waveguide. Bringing the gold strip close to the dielectric waveguide results in a coupling of the individual modes forming two hybrid SRSPP/dielectric modes A and B which are nondegenerate, where their superpositions (A+B and A-B) are concentrated in the metal and in the dielectric, respectively. In accordance with coupled mode theory [2] optical power is transferred from the metal strip to the dielectric waveguide (or vice versa). The field distributions and phase velocities of the different structures are determined by the finite element method (FEM). The FDTD method is used to verify the coupling length. Because the SRSPP mode is so strongly confined to the metal strip very short coupling lengths were simulated, to use this device as an ultra-short coupler between plasmonic and dielectric structures. [1] Wan et al., Appl.Phy.Lett. 94, (2009) [2] Yariv & Yeh, Optical Waves in Crystals (2002), ISBN:

96 Thu, 16:50, Invited Superconducting properties of multi-filamentary MgB2 wires Michael Reissner 1, Stefan Sorta 1, Lukas Bulla 1, Tibor Melisek 2, Pavol Kovac 2 1 Vienna University of Technology, Wiedner Hauptstrasse 8-10, 1040 Vienna, Austria 2 Slovak Academy of Sciences, Dúbravská cesta 9, Bratislava, Slovak Republic Many efforts are underway to produce multi-filamentary wires of MgB2, where the superconducting filaments are embedded in good conducting material. Unfortunately strong chemical reactions between MgB2 and Cu deteriorate superconducting properties strongly. Therefore barrier sheaths between both materials are necessary. For these Nb and Ti are found to be useable. The important question is, how superconducting properties depend on the reduction of both filament diameter and barrier thickness. In this work we report on magnetic investigation of a series of MgB2 wires, with nineteen filaments. All samples were prepared in the same way, but with filament diameters between 58.8 and 17.7 µm. With decreasing filament diameter the width of superconducting transition increases, although superconducting transition itself is not changed. Critical current density and irreversibility line also decrease. From magnetic relaxation measurements mean effective activation energies U are determined. They are also decreasing with decreasing filament diameter. The temperature dependence of U points to the existence of a pinning energy distribution, which broadens with decreasing filament diameter. Thu, 17:20 Combining SQUID magnetometry with in-situ cyclic voltammetry to study the electrochemical charging-induced variation of the magnetic moment of γ-fe 2 O 3 nanoparticles Stefan Topolovec 1, Heinz Krenn 2, Roland Würschum 1 1 Graz University of Technology, Petersgasse 16, 8010 Graz, Austria 2 University of Graz, Universitätsplatz 5, 8010 Graz, Austria Electrical tuning of magnetic properties has emerged as an important topic of materials research in the last years. Recently, we could demonstrate that the magnetic moment of γ-fe 2 O 3 nanoparticles can be tuned reversibly by electrochemical charging [1]. In order to study the electrochemical processes taking place and their influence on the magnetic moment in more detail, we have now designed a special electrochemical cell, allowing the recording of cyclic voltammograms in-situ in a SQUID magnetometer. To charge the insulating γ-fe 2 O 3 nanoparticles, which were prepared by microwave plasma synthesis, a porous pellet of γ-fe 2 O 3 nanoparticles and Pt nanoparticles was formed. The charging of the pellet was performed in an aqueous electrolyte of 1M KOH. Reversible variations of the magnetic moment of γ-fe 2 O 3 nanoparticles up to several percent could be achieved. From the combined measurements of cyclic voltammograms and the magnetic moment it became obvious, that the charging coefficient s = m/ Q significantly depend on the examined potential range. The variation of the nanoparticles moment is considered to arise from reversible electrochemically induced reactions at the surface of the γ-fe 2 O 3 nanoparticles. In addition, charging induced variations of the magnetic surface anisotropy may play a role. Financial support by the FWF Austrian Science Fund is appreciated (project S10405-N16). [1] T. Traußnig et al., Phys. Status Solidi - Rapid Res. Lett. 5 (2011)

97 Thu, 17:35 Transport beyond Brownian Motion Colored noise Thomas Franosch 1, Matthias Grimm 1, Maxim Belushkin 1, Flavio Mor 1, Giuseppe Foffi 1, László Forró 1, Sylvia Jeney 1 1 Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstrasse 7, Erlangen, Germany Brownian motion is one of the pillars of statistical physics with applications ranging from astrophysics to biological physics. The theoretical foundation is well understood since Einstein and Smoluchowski introduced a probabilistic interpretation to derive diffusion as a macroscopic law. In modern language, the diffusion propagator follows from the central limit theorem. Although the mean-square displacement is dominated by the linear increase for long times and finite diffusion constant, persistent correlation underlying the transport may be unraveled by studying the corresponding velocity autocorrelation functions (VACF). I will discuss recent theoretical, simulation, and experimental advances highlighting power-law tails in the VACF which correspond to a colored component in the power spectrum of the force correlator due to hydrodynamic backflow [1,2]. [1] T. Franosch et al., Nature 478, (2011) [2] S. Jeney et al., Phys. Rev. Lett. 100, (2008) Thu, 17:50: FKP & NESY member meeting Fri, 09:00-11:00, HS Fri, 09:00 Comparison of MOS and Schottky-barrier structure in AlGaN/GaN HEMTs Mattia Capriotti 1, Alexander Alexewicz 1, Anil Parlar 1, Frank Brunner 2, Aaron Maxwell Andrews 1, Dionyz Pogany 1, Gottfried Strasser 1 1 Vienna University of Technology, Floragasse 7, 1040 Vienna, Austria 2 Ferdinand Braun Institut, Gustav-Kirchhoff-Strasse 4, Berlin, Germany GaN high electron mobility transistors (HEMTs) for power switching and digital applications require a low gate leakage current (Ig) and a high threshold voltage, allowing normally-off operation, but no common solution has been presented yet. It is known that engineering fixed charges at the barrier/oxide interface creates both normally-off and normally-on devices with the same heterostructure. In this work, we present a comparison between metal oxide semiconductors (MOS) and Schottky-barrier (SB) AlGaN/GaN HEMTs. We investigate devices with a heterostructure consisting of a 2 mm thick GaN buffer, 16 nm Al0:24Ga0:76N barrier and a 3 nm GaN:Si cap layer. In the MOSHEMT devices, after recessing the GaN cap layer below the gate, ZrO 2 layers of 10 and 15 nm are deposited by atomic layer deposition on the barrier. Depositions were performed at 150 C and at 2000 C. In SB devices the Ni/Au gate metallization is deposited directly on the barrier. The SB samples show an exponential increase of Ig for a forward gate bias Vgf > 3 V, while the inclusion of a ZrO 2 interlayer allows to increase the Vgf up to 8 V for the same Ig. Low values of Ig at a high gate bias indicate better gate oxide structural properties. Contrary to SB devices, the MOSHEMTs exhibit large hysteresis in the transfer characteristics, indicating charges at the interface ( cm 2 ). 95

98 Fri, 09:15 Interface Morphology of an Orthogonal Soluble Polymer Transistor Alfred Neuhold 1, Hannes Brandner 1, Simon Ausserlechner 1, Stefan Lorbek 2, Markus Neuschitzer 1, Egbert Zojer 1, Christian Teichert 2, Roland Resel 1 1 Graz University of Technology, Petersgasse 16, 8010 Graz, Austria 2 Montanuniversität Leoben, Franz-Josef-Straße 18, 8700 Leoben, Austria Understanding the interfacial properties of an organic multilayer arrangement is crucial when intending to use such structures in electronic devices. In this work we focus on the interface morphology of orthogonal soluble polymers in a solution processed polymer field effect transistor (PTFT). A water soluble poly-(4-styrenesulfonic acid) (PSSA) was solution deposited as a layer to modify the properties of the gate dielectric and on top of it the poly-(3-hexylthiophene) (P3HT) was spin cast as organic semiconducting polymer. Two relatively a-polar solvents (either chloroform or toluene), were used for the P3HT deposition. Gracing incidence X-ray diffraction was used to determine the orientation of the P3HT crystallites, which were face-on aligned for P3HT dissolved in chloroform and edge-on aligned for P3HT dissolved in toluene. The surface and interface roughness was investigated by X-ray reflectivity experiments and the surface roughness was cross-checked by atomic force microscopy. First experiments regarding the performance of these layers in thin-film transistors were conducted and revealed a one order of magnitude higher charge carrier mobility when spin-coating the P3HT film from toluene compared to the device for which chloroform has been used as solvent for P3HT deposition. This is assigned to the better defined PSSA/P3HT(toluene) interface morphology. Fri, 09:30 Temperature Induced Wetting and Dewetting Effects of Dioctylbenzothieno-benzothiophene on Silicon Oxide Surfaces Michael Dohr 1, Oliver Werzer 2, Quan Shen 3, Roland Resel 1, Christian Teichert 3, Yves Geerts 4, Michele Sferrazza 4, Ingo Salzmann 5 1 Graz University of Technology, Petersgasse 16, 8010 Graz, Austria 2 University of Graz, Humboldtstraße 46/I, 8010 Graz, Austria 3 Montanuniversität Leoben, Franz-Josef-Straße 18, 8700 Leoben, Austria 4 Université Libre de Bruxelles, CP 206/01 Campus de la Plaine, 1050 Bruxelles, Belgium 5 Humboldt-Universität zu Berlin, Unter den Linden 6, Berlin, Germany The excellent performance of the molecule dioctyl-benzothieno-benzothiophene (C 8 -BTBT) in organic thin film transistors is strongly influenced by heat treatment. Spin coating of the film at elevated temperatures (within the liquid-crystalline state), leads to an increase in charge carrier mobilities up to 3 cm 2 /V s. The structural properties of C 8 -BTBT thin films are investigated as a function of temperature in terms of crystallographic properties and morphology. Spatially resolved microscopic methods (AFM and optical microscopy) as well as integral characterisation methods (Grazing incidence x-ray scattering, x-ray reflectivity) are used. The disordered monolayer film (thickness 2.4 nm) remains unstable after the spin coating process. With increasing temperatures, dewetting of the monolayer is observed by the formation of crystalline islands with an average height of about 15nm. Approaching the transition temperature to the smectic state, at a temperature of 90 C, re-wetting is observed and a monolayer is formed on the substrate surface. This monolayer (thickness 2.9 nm) remains stable in the liquid crystalline state as well as after cooling back to room temperature. Also multilayer films show pronounced dewetting during heating by the formation of huge crystalline islands with a lateral size in the µm range. At 105 C a monolayer (thickness 2.9 nm), at 108 C a bilayer and at 115 C a triple layer has developed. Decreasing temperatures reveal the reversibility of the layer-by-layer formation. All found layered structures can be stabilized by rapid cooling. 96

99 Fri, 09:45 Metastable structures and phases of intermetallics produced by severe plastic deformation David Geist 1, Christoph Gammer 1, Peter Karnthaler 1, Christian Rentenberger 1 1 University of Vienna, Boltzmanngasse 5, 1090 Vienna, Austria Metastable solid structures and phases such as nanostructured or amorphous phases are of general high scientific and technological interest since they often exhibit properties different from their crystalline, coarse-grained counterparts. In order to obtain metastable structures with an increased free energy different methods can be applied. In the last decade methods of severe plastic deformation were established to produce bulk materials comprising metastable phases. In this work we show the structural analysis of metastable structures and phases on different length scales using scanning (SEM) and transmission electron microscopy (TEM) methods. The metastable structures were produced by high-pressure torsion of L12 long-range ordered intermetallic alloys (Ni 3 Al, Zr 3 Al, Co 3 Ti) based on the fcc lattice. The SEM and TEM analyses show that the metastable structures evolve heterogeneously during deformation [1]. Depending on the type of lattice defects induced by deformation different saturation structures are produced: a nanocrystalline structure showing the loss of chemical long-range order (Ni 3 Al) or an amorphous one. TEM methods reveal that in Zr 3 Al the amorphous phase contains residual nanograins of the initial phases whereas in Co 3 Ti devitrified nanocrystals of a structure different to the initial one are embedded in the amorphous phase. In the latter case devitrification occurs in the course of deformation of the amorphous phase. [1] D. Geist, C. Rentenberger, H.P. Karnthaler. Acta Mater. 59 (2011) This work was supported by the Austrian Science Fund (FWF):[P22440]. The authors acknowledge the use of the SEM of the Faculty Center for Nanostructure Research. Fri, 10:00, Invited Quantitative analysis of liquid jets breakup with SAXS Benedetta Marmiroli 1, Fernando Cacho-Nerin 1, Barbara Sartori 1, Javier Perez 2, Heinz Amenitsch 1 1 Österreichische Akademie der Wissenschaft, Schmiedlstrasse 6, 8042 Graz, Austria 2 Synchrotron SOLEIL, L Orme des Merisiers BP 48 Saint-Aubin, Gif sur Yvette Cedex, France The breakup of liquid jets represents a wide area of research in the field of multiphase flows, fully justified by their wide presence both in industrial and in scientific applications. Moreover, the recent development of microfluidic systems has raised great interest in understanding the flows in small spatial dimensions. Such interest has been further increased due to the evolution of free electron lasers and the consequent need to develop new, high throughput techniques to characterize biological macromolecules. Jet instability has been widely described both theoretically and by performing sumulations, however there is still need to have accurate sets of experimental data. In fact most of them are based on light scattering which is disturbed by reflection, absorption and multiple scattering of droplets and air interface morphology, and on camera imaging which is limited by the dimension of the phenomena that can be seen. In the present communication we want to show the potentiality of synchrotron SAXS in providing quantitative information on the dynamics of liquid jets at the nanoscale. To this purpose, we have investigated free liquid jets in air with circular nozzle geometry of different diameters (450µm-100µm), flow rates (2-10 ml/min), and solvents (water, ethanol, isopropanol and their mixtures). We determined their time dependent morphology and their breakup length in the Rayleigh and first wind-induced regimes. The resulting data are considered as basis for the use of free jet micromixers to examine the evolution of chemical and biological reactions by SAXS. 97

100 Fri, 10:30 Direct measurements of reversible free-volume formation in bulk Zr 56 Al 7 Cu 24 Ni 10 Co 3 glass below the glass transition temperature Martin Luckabauer 1, Rainer Wunderlich 2, Hans-Jörg Fecht 2, Wolfgang Sprengel 1 1 Graz University of Technology, Petersgasse 16, 8010 Graz, Austria 2 Universität Ulm, Albert-Einstein-Allee 47, Ulm, Germany Most models regarding the glass transition are based on information obtained from the supercooled liquid state, either by experiment or by simulation. The slowing down of molecular or atomic motion occurring at the glass transition makes the kinetics difficult to access for common measurement techniques at lower temperatures. However, possible changes around Tg regarding the structural dynamics are believed to yield key parameters in understanding the glass transition. We report the measurement of thermally activated reversible formation and disappearance of free volume in bulk Zr 56 Al 7 Cu 24 Ni 10 Co 3 glass by means of high-resolution laser dilatometry in the lower temperature regime around the glass transition. The measurement technique involving a 2-beam Michelson laser-interferometer is contactless and allows access to time constants of up to s. From isothermal length change measurements at different temperatures after fast temperature changes the underlying atomic processes were studied. According to a first analysis the behavior can be described by an Arrhenius relation with high activation energy. Financial support by the Austrian Science Fund (FWF) is appreciated (project P22645-N20). Fri, 10:45 Positron annihilation spectroscopy on LiCoO2-electrodes with different lithium content Peter Parz 1, Werner Puff 1, Roland Würschum 1, Bernd Fuchsbichler 2, Stefan Koller 2 1 Graz University of Technology, Petersgasse 16, 8010 Graz, Austria 2 VARTA Micro Innovation GmbH, Stremayrgasse 9, 8010 Graz, Austria LiCoO2 is widely used in Li-ion battery systems as an intercalation electrode material. Reversible charge/discharge cycling of LiCoO2 is only possible up to 50% of the available Li-ions, further removal of Li-ions drastically reduces the capacity and cycle stability. The extraction of lithium ions is expected to leave open volumes, which should act as positron traps. Therefore, Positron Annihilation Lifetime Spectroscopy (PALS) was applied on a LiCoO2 electrode material, to monitor the changes of the mean positron lifetime upon different discharge levels. The electrodes consist of LiCoO2 with addition of carbon for electrical conductivity and a polymer binder. These electrodes were then discharged to LixCoO2, with x = 1, 0.8, 0.7, 0.6, 0.55, 0.5, 0.4 and 0.3. The electrodes were disassembled, rinsed and dried in argon atmosphere and ex-situ investigated by positron lifetime spectroscopy. For a lithium content of the LixCoO2 of x = a linear increase of the mean positron lifetime could be monitored, which can be attributed to an increase in size and concentration of the free volume, due to missing lithium ions and in addition to a monoclinic distortion of the hexagonal structure, due to Coulomb repulsion of the remaining negatively charged CoO2 groups. Upon further removal of lithium x = a strong deviation from the linear increase of the mean positron lifetime could be monitored, which can be attributed to the dissolution of CoO2 from the electrode. 98

101 Fri, 11:00-11:30: Coffee break Fri, 11:30-13:00, HS Fri, 11:30, Invited Self Assembly of Mesoporous Materials in the Gas-Phase: An in situ SAD Study Heinz Amenitsch 1, Benedetta Marmiroli 1, Fernando Cacho-Nerin 1, Barbara Sartori 1, Karin Jungnikl 1, Ibrahimkutty Shyjumon 2, Peter Laggner 3, Michael Rappolt 1 1 Österreichische Akademie der Wissenschaft, Schmiedlstrasse 6, 8042 Graz, Austria 2 Institute for Synchrotron Radiation, Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen, Germany 3 Bruker AXS GmbH, Oestliche Rheinbrueckenstrasse 49, Karlsruhe, Germany Evaporation induced self assembly (EISA) provides an attractive method for the synthesis of mesostructured materials. A fast and economically interesting process for the production of mesostructured particles is the spray-drying process of aerosol droplets, in which the mesophase formation proceeds within a few seconds, but still, a high degree of control on the final mesostructure is possible by applying suitable process parameters. Besides the chemical composition, also the external conditions influencing the evaporation rate (e.g. temperature, relative humidity) have been identified as key parameters for the resulting structure of the mesophase. Most of the previous studies have been performed on the dried aerosol and provided information on the effect of such parameters on the final structure or at the end of the evaporation chamber. For the in situ study, various setups were designed that enables the gas-phase measurements during the evaporation process. In an elongated evaporation vessel temperature gradients from a starting temperature (e.g. 5 C) to final temperatures up to 400 C can be applied within a few centimetres in the axial direction and provoke a fast evaporation of the volatile components of the ESIA process. X-ray measurements can be taken at steps along the temperature profile in the dryer tube and the selfassembly process can be followed with SWAXS. This presentation should give an overview of the different experiments starting from the ex-situ deposition, in situ experiments of mesoporous materials and finally hierarchical assembly of more complex structures. 99

102 Fri, 12:00 Mechanical properties of carbon nanostructures investigated by Monte Carlo simulations Markus Hartmann 1, Melanie Todt 2, David Holec 1, Paul Mayrhofer 1, Oskar Paris 1, Franz Fischer 1, Franz Rammerstorfer 2 1 Montanuniversität Leoben, Franz-Josef-Straße 18, 8700 Leoben, Austria 2 Vienna University of Technology, Gußhausstrasse 27-29, 1040 Vienna, Austria Carbon nanostructures are a fascinating class of materials combining high stiffness with low weight and exceptional toughness that makes carbon a promising candidate for applications in structural mechanics. Understanding the mechanical behavior of carbon structures also on atomistic length scales is inevitable in describing the mechanical performance and stability of large, hierarchical structures like carbon onions and fibers. In the presented work ab initio calculations were used to extract classical potentials describing stretching, bending and torsion deformations of carbon bonds [1] that were used in subsequent Monte Carlo simulations to perform computational mechanical tests on graphene, carbon nanotubes and fullerenes. These tests included the application of hydrostatic pressure, the application of a ring load and the deformation of a fullerene between two plates. We analyzed the elastic response, as well as the stability limits and postbuckling behavior of the structures for different sizes. The simulation results were compared to the predictions of finite element methods to evaluate macroscopic parameters like elastic modulus or Poisson ratio of the investigated structures. In fullerenes special attention was paid to the influence of pentagons that are inherently present in these structures. It was observed that the pentagons deform less than the atomic bonds in hexagonal geometry. [1] Holec et al., Phys. Rev. B 81, (2010) Fri, 12:15 Topologically nontrivial and nearly flat bands in multi-orbital models Maria Daghofer 1, Stefanos Kourtis 1, Jörn Venderbos 1, Jeroen van den Brink 1 1 IFW Dresden, Helmholtzstrasse 20, Dresden, Germany For topologically nontrivial and very narrow bands, Coulomb repulsion between electrons has been predicted to give rise to a spontaneous fractional quantum-hall (FQH) state in absence of magnetic fields. We show that orbital degrees of freedom in frustrated lattice systems lead to a narrowing of topologically nontrivial bands for robust parameter ranges. We find that a strongly correlated t 2g system on a triangular lattice can support a spin-chiral magnetic ordering pattern with such topologically nontrivial and flat bands. In order to go beyond mean field and to study the impact of longer-range interactions, we map the low-energy electronic states onto an effective one-band model. Exact diagonalization is then used to establish signatures of a spontaneous FQH state. [1] J. W. F. Venderbos, M. Daghofer and J. van den Brink, Phys. Rev. Lett. 107, (2011); J. W. F. Venderbos, S. Kourtis, J. van den Brink and M. Daghofer, Phys. Rev. Lett. 108, (2012). 100

103 Fri, 12:30 Itinerant electrons in a 2-dimensional spin-ice system: Kondo-Lattice model on the checkerboard lattice Jörn Venderbos 1, Maria Daghofer 1, Jeroen van den Brink 1, Sanjeev Kumar 2 1 IFW Dresden, Helmholtzstrasse 20, Dresden, Germany 2 IISER Mohali, Knowledge city, Sector 81, SAS Nagar, Manauli PO , India We investigated the theory of the interplay of itinerant electrons and localized magnetic moments on the frustrated checkerboard lattice as function of the super-exchange interaction between the localized moments and the band filling of fermions. We find that at half filling a very robust magnetic flux phase is lowest in energy. The ordering of the localized spins induces an effective gauge field flux of π for the electrons. Consequently, this phase preserves time-reversal symmetry and the low-energy effective theory of the electrons is that of massless Dirac fermions, resembling the situation in graphene except that the spin degree of freedom is absent here. The robustness of this state originates from the geometrical frustration of the checkerboard lattice. In the crossover regime from this flux state and the saturated FM state at vanishing super-exchange coupling, these Dirac fermions become massive with opposite sign of the mass at the two degeneracy points. This chiral spin state is then equivalent to a time-reversal breaking anomalous Quantum Hall phase, precisely in the way once envisioned by Haldane in graphene. 101

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105 9 History of Physics (GEP) HS (Physics Building) History of Physics Geschichte der Physik Peter M. Schuster, Thursday, 20 th September 2012, HS :00-14:00 Time Presenter Title 13:00-13:20 Franz Sachslehner Franz Serafin Exner der Anfang des II. Physikalischen Institutes 13:20-13:40 Wolfgang Reiter Karl Przibram ( ) Pionier der nuklearen Festkörperphysik 13:40-14:00 Andreas Golob Graz physicists as agents of popular education. The role of physics in the Graz university-extension movement :00-14:20 Coffee break Thursday, 20 th September 2012, HS :20-15:20 Time Presenter Title The stony cosmos of Andreas 14:20-14:40 Reinhard Folk Pleninger Astronomy and Astrology in the 16 th century Joseph Liesganig und die geodätische 14:40-15:00 Bruno Besser Vermessung zweier Meridianbögen in Österreich-Ungarn 15:00-15:20 Armand Kraml Eine physikalische Reise durch Westeuropa im Jahr :20-15:40 Coffee break Thursday, 20 th September 2012, HS :40-16:20 Time Presenter Title 15:40-16:00 Franz Pichler Elektrisiermaschinen Ein Streifzug an Hand des Schrifttums von 1600 bis :00-16:20 Heinz Krenn Boltzmanns Bizykel ein mechanisches Analogon gekoppelter elektrischer Stromkreise 103

106 Thu, 13:00-14:00, HS Thu, 13:00 Franz Serafin Exner der Anfang des II. Physikalischen Institutes Franz Sachslehner 1 1 Universität Wien, Strudlhofgasse 4, 1090 Wien, Austria Franz Serafin Exner ( ) folgt 1891 auf Josef Loschmidt als Vorstand des Physikalisch- Chemischen Institutes der Universität Wien. Ihm gelingt es, mehr Raum und Personal zu erhalten und sein Institut allmählich besser zu versorgen. Nach dem Tod Josef Stefans (1893) wird versucht, Ludwig Boltzmann als Leiter des Physikalischen Instituts zu engagieren. Es tritt die Situation ein, dass im Physikalischen Institut niemand die experimentellen Praktika abhalten will, andererseits wurde im Physikalisch-Chemischen Institut nie wirklich physikalische Chemie gemacht. Exner übernimmt schließlich die Ausbildung in den experimentellen Praktika. So kommt es durch den Einfluss Ludwig Boltzmanns 1902 zur Neuordnung der physikalischen Institute, wobei Exners Institut als II. Physikalisches Institut hervorgeht. Aufgrund des baufälligen Hauses in der Türkenstraße 3 betreiben Exner, Boltzmann und Viktor v. Lang (sowie später Lechner) den Neubau für die physikalischen Institute in der Boltzmanngasse 5 (eröffnet 1913). Exner wirkte auch bei der Planung des Radiuminstitutes mit (1910 eröffnet) und war dessen Kurator zeit seines Lebens. Wissenschaftlich war er sehr vielseitig. Seine wichtigsten Gebiete waren: Elektrochemie, Luftelektrizität, Spektralanalyse und Farbenlehre. Er war auch ein Förderer der Erforschung der Radioaktivität. Weiters gibt es interessante erkenntnistheoretischen Arbeiten. Exner war ein beliebter und erfolgreicher Lehrer. Namen wie Hans Benndorf, Stefan Meyer, Egon v. Schweidler, Eduard Haschek, Marian Smoluchowski, Erwin Schrödinger und andere zeugen davon. Die späteren Nobelpreisträger Victor Franz Hess und Erwin Schrödinger waren jahrelang Mitarbeiter Exners. Thu, 13:20 Karl Przibram ( ) Pionier der nuklearen Festkörperphysik Wolfgang Reiter 1 1 Universität Wien, Spitalgasse 2-4, 1090 Wien, Austria Vor den Hintergrund der Rolle des liberalen jüdischen Wiener Bürgertums des ausgehenden 19. und beginnenden 20. Jahrhunderts für die Förderung und Entwicklung von Wissenschaft und Kunst werden die wissenschaftlichen Leistungen von Karl Przibram und seiner Arbeitsgruppe am Institut für Radiumforschung bis 1938 sowie dessen Wirken nach seiner Rückkehr aus dem belgischen Exil an der Universität Wien nach 1945 dargestellt. 104

107 Thu, 13:40 Graz physicists as agents of popular education. The role of physics in the Graz university-extension movement Andreas Golob 1 1 Universität Graz, Universitätsplatz 3, 8010 Graz, Austria When the idea(l)s of the university-extension movement reached Graz from Cambridge (1871) via Vienna (1895) in 1898, aspects of physics became regular topics of the so called Volkstümliche Vorträge, that is popular lectures. Numerous branches of the subject, like astronomy, experimental physics, geophysics and meteorology, were involved, links existed towards technical application, for example, the development of power stations, the electric grid and electric light was supported. On the other hand the dangers of this new energy source were illustrated by physicians. Representatives of the subject included less known local professors such as Leopold Pfaundler, Hans Benndorf and Heinrich Ficker von Feldhaus, but also some internationally renowned scientists like Victor F. Hess, Erwin Schrödinger and Alfred Wegener. The presentation, which is part of a work in progress on the local university-extension movement as a whole, will statistically show the contents of the relevant contributions and will demonstrate a handful of cases to show how knowledge was presented and which means, like pictures, films, experiments, were used to illustrate the talks. Correspondence with local organisers in and outside Graz can also highlight attitudes towards and, respectively, reactions of the audience and help to examine the impact of the lectures which should not only attract the educated bourgeoisie but also labourers and farmers, men and women alike. Early statistics will also shed some light on this question. Thu, 14:00-14:20: Coffee break 105

108 Thu, 14:20 The stony cosmos of Andreas Pleninger Astronomy and Astrology in the 16 th century Reinhard Folk 1 1 Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz, Austria In the years 1590 to 1607 six stony tables under the tile Calendarium Perpetuum were created by Andreas Pleninger. They demonstrate the topological order at that time. In particular on three of this tables (on the tables in the monastery Chremsminster, in the historical museum in Regensburg and in the museum in Kassel) one finds an astrolabe, on two of them a horoscope and on one the starmaps of the northern and southern celestial sphere. The sources of this artworks and their relation to the cosmic conceptions of that time will be discussed. [1] P. Altman Pötsch, Der ewigwährende Kalender im astronomischen Kabinett der Sternwarte genannt Astronomischer Tisch, Öffentliches Stiftsgymnasium Kremsmünster Jahresbericht, Thalheim [2] P. Altman Pötsch und R. Folk, Der astronomische Tisch des Andreas Pleninger aus dem Jahr 1603, eingereicht in: Anzeiger des Germanischen Nationalmuseums [3] R. Folk, Das Astrolabium am Kalendertisch im Historischen Museum in Regensburg Thu, 14:40 Joseph Liesganig und die geodätische Vermessung zweier Meridianbögen in Österreich-Ungarn Bruno Besser 1 1 IWF, Schmiedlstrasse 6, 8042 Graz, Austria Joseph Liesganig, 1719 in Graz geboren, studierte ab 1734 Mathematik, Physik und Astronomie an der Grazer Jesuitenuniversität. Daran anschließend studierte er Theologie an der Jesuitenuniversität Wien und wurde 1749 Prediger in Komarno (damals Ungarn, heute Slowakei). Nach einem einjährigen Aufenthalt als Mathematikprofessor am Jesuitenkolleg in Kaschau (heute Kosice, Slowakei) kehrte er 1752 als Mathematikprofessor an das Wiener Kolleg zurück und wurde auch verantwortlich für die dortige Jesuitensternwarte (unter der Führung von Maximilian Hell). Nach der Auflösung des Jesuitenordens im Jahr 1773 verließ Liesganig Wien und wurde Direktor der staatlichen Vermessung für Galizien und Lodomerien in Lemberg (heute Lwiw, Ukraine), wo er auch 1799 starb. Bereits 1761/2 wurde Liesganig von Erzherzogin Maria Theresia mit der Vermessung eines Meridians in Österreich-Ungarn beauftragt, woraufhin er den Meridian von Brünn (heute Brno, Tschechien) bis Warasdin (heute Varazdin, Kroatien) auswählte und mit Hilfe eines Triangulationsnetzes ausmaß. Für diese Arbeiten wurde je eine Basislinie im Marchfeld und zwischen Wiener Neustadt und Neunkirchen eingemessen. Die Arbeiten an der Meridianmessung brachten ihn auch wieder in seine steirische Heimat und 1767 waren die Arbeiten abgeschlossen. In den darauffolgenden zwei Jahren vermaß Liesganig auch einen Meridianbogen in Ungarn, zwischen Kistelek und Czurok (heute Curug, Serbien). 106

109 Thu, 15:00 Eine physikalische Reise durch Westeuropa im Jahr 1838 Armand Kraml 1 1 Sternwarte Kremsmünster, Stift Kremsmünster, 4550 Kremsmünster, Austria Im Sommer 1838 unternahmen drei österreichische Physiker eine wissenschaftliche Reise durch halb Europa. Die Reisegesellschaft setzte sich zusammen aus August Kunzek ( ), damals Professor für Physik in Lemberg, Andreas von Ettingshausen ( ), Professor für Physik an der Universität Wien und P. Marian Koller ( ), Direktor der Sternwarte Kremsmünster. Aus Kollers Aufzeichnungen soll diese Reise für die Geschichte der Physik jener Zeit ausgewertet werden. Die Reise ging über Prag nach Berlin, Hamburg und Altona, dann per Schiff nach London. Von dort begab man sich nach Paris und Brüssel. Am Schluss stand die Teilnahme an der Versammlung der Deutschen Ärzte und Naturforscher, die in diesem Jahr in Freiburg im Breisgau abgehalten wurde. Über München ging es dann wieder nach Hause. Im Vordergrund standen vor allem Besuche der Sternwarten sowie physikalischer Werkstätten und Laboratorien. Mit der Darstellung dieser Reise wird gleichsam ein Schnappschuss auf die aktuellsten Arbeitsbereiche von astronomischer und physikalischer Forschung im Jahr 1838 gemacht. Dieser Begriff aus der Fotografie bietet sich besonders an, da gerade junge Technologie auf die drei Reisenden damals eine besondere Anziehungskraft ausübte. Thu, 15:20-15:40: Coffee break 107

110 Thu, 15:40 Elektrisiermaschinen - Ein Streifzug an Hand des Schrifttums von 1600 bis 1800 Franz Pichler 1 1 Johannes Kepler University, Altenbergerstrasse 69, 4040 Linz, Austria Der Vortrag zeigt in einer Bilderfolge anhand von im Original vorliegenden Büchern die verschiedenen Konstruktionen und Bauformen von Reibungselektrisiermaschinen, wie diese vom Physiker, Instrumentenmacher und Schausteller im Zeitraum von 1600 bis 1800 behandelt wurden markiert das Jahr, in dem der englische Arzt und Wissenschaftler William Gilbert sein Werk De Magnete veröffentlichte, in dem zum erstenmal Elektrizität vorkommt. Das Jahr 1800 zeigt die Entdeckung des galvanischen Elementes durch Alessandro Volta an, eine Entdeckung, die für die Physik eine neue Orientierung in der Erforschung der Elektrizität ermöglichte. Wenn auch heute Reibungselektrisiermaschinen der vorgestellten Art keine große Bedeutung mehr haben, so haben deren Entwicklung und die daran durchgeführten Experimente dennoch einen wichtigen Beitrag zur Erforschung des physikalischen Phänomens der Elektrizität beigetragen. Thu, 16:00 Boltzmanns Bizykel ein mechanisches Analogon gekoppelter elektrischer Stromkreise Heinz Krenn 1 1 Universität Graz, Universitätsplatz 5, 8010 Graz, Austria Hermann Helmholtz hatte den Begriff der zyklischen Bewegung für stationäre Vorgänge in die klassische Mechanik eingeführt, womit er den Zustand einer Bewegung ohne sichtbare äußere Veränderung beschrieb: Die bewegten Massenpunkte eines rotierenden Körpers werden ständig durch zyklische Bewegung ersetzt, sodass der Körper keine geometrische Veränderung außer eine Rotation - erfährt. Dies gilt nicht nur für stationär fließende Strömungen, sondern auch für die fließende Elektrizität, den elektrischen Strom. Ludwig Boltzmann hat das Helmholtz sche Monozykel, das derartige zyklische Bewegungen beschreibt, auf das sogenannte Bizykel erweitert, einem mechanischen Apparat mit zwei gekoppelten Monozykeln. Ein ausgeklügelter Mechanismus beschreibt die Vorgänge gekoppelter Bewegungen und ist ein perfektes Analogon für gekoppelte elektrische Stromkreise, wie z.b. einem elektrischen Transformator. In Ermangelung geeigneter elektronischer Aufzeichnungsgeräte (wie z.b. einem Elektronenstrahl-Oszilloskop) stellte das Boltzmannsche Bizykel ein hervorragendes Demonstrationsobjekt dar, um elektrische Vorgänge zu veranschaulichen. Die Konstruktion des Bizykel verdeutlicht die hohe Kompetenz von Ludwig Boltzmann als hervorragenden Experimentalphysiker, was selbst in Fachkreisen zu wenig gewürdigt wurde. 108

111 10 Medical, Bio and Environmental Physics (MBU) SR Medical, Bio and Environmental Physics Medizinische Physik, Biophysik und Umweltphysik Günther Schauberger, Thursday, 20 th September 2012, SR :30-15:30 Time Presenter Title 14:30-14:40 Günther Schauberger Opening of the Topical Session MBU 14:40-15:00 Christina Hofstätter Monitoring of Radiation Exposure in the European Columbus Laboratory of the International Space Station 15:00-15:20 Otto Scheibelhofer (Multiawesome) Multispectral Multiprobe Monitoring 15:30-15:50 Coffee break Thursday, 20 th September 2012, SR :50-16:30 Time Presenter Title 100-year record of 236-U/238-U in 15:50-16:10 Stephan Winkler coral as a step towards establishing 236-U as oceanic tracer 16:10-16:30 Georg Pabst Stalk-free membrane fusion of cationic lipids via an interdigitated phase 109

112 Thursday, 20 th September 2012, SR minute Poster Presentations 16:30-17:00 Time Poster-ID Presenter Title Review and Crosscomparison of Matroshka 16:30-16:35 POS-45 Christina Hofstätter Phantom Measurements in Different Compartments of the International Space Station Bioequivalent Solid-State 16:35-16:40 POS-44 Michael Hajek Dosimetry: Current Trends and Future Developments Korrelation relativer 16:40-16:45 POS-46 Maryam Nikbakhti Feuchte und Stromumwandlungskoeffizient der Dünnschicht-Photovoltaik 16:45-16:50 POS-43 Carlos Armando Alberti Ground based MAX-DOAS observations of tropospheric trace gases in San Salvador, El Salvador 17:00 Wahl des Vorsitzenden des Fachausschusses MBU Please find the corresponding abstracts in the poster section of this book by looking up the Poster-ID Thu, 14:40-15:30, SR

113 Thu, 14:40 Monitoring of Radiation Exposure in the European Columbus Laboratory of the International Space Station Christina Hofstätter 1, Michael Hajek 1, Thomas Berger 2, Christine Körner 2, Günther Reitz 2 1 Vienna University of Technology, Stadionallee 2, 1020 Wien, Austria 2 German Aerospace Center, Linder Höhe, Köln, Germany Cosmic radiation and its secondaries created in interactions with spacecraft shielding structures constitute one of the most important hazards associated with human spaceflight. Crewmembers are facing exposures to radiation qualities that are known to produce distinct biological damage compared with radiation on ground, and dose levels that may easily exceed those routinely received by terrestrial radiation workers. DOSIS is a comprehensive and overarching international dosimetry programme coordinated by the German Aerospace Centre, supporting assessment of potential biological implications on the health of space crew. It maps the distribution of the radiation environment in the European Columbus laboratory of the International Space Station (ISS) using a comprehensive set of active and passive instrumentation to account for the cosmic-ray charge and energy spectrum. Passive detector packages accommodating luminescence and plastic nuclear track detectors (PNTD) measured absorbed dose and linear energy transfer (LET) spectra at eleven sites throughout Columbus for mission durations of 135 days (July to November 2009) and 191 days (November 2009 to May 2010). Discussion focuses on thermoluminescence dosimetry (TLD) results but strives exemplary the convolution of TLD and PNTD data to derive dose equivalent and evaluate the significance of the high-let ( 10 kev/µm) contribution to the TLD dose. The absorbed dose distribution determined by different luminescence phosphors showed a high degree of consistency and a distinct spatial pattern with variations of up to 22% between the sites. The decreased dose rate observed for the second mission is attributed to increasing solar activity and ISS altitude changes. Thu, 15:00 (Multiawesome) Multispectral Multiprobe Monitoring Otto Scheibelhofer 1, Roland Hohl 1, Stefan Sacher 1, José Menezes 1, Johannes Khinast 1,2 1 Research Center Pharmaceutical Engineering GmbH, Inffeldgasse 21a, 8010 Graz, Austria 2 Graz University of Technology, Inffeldgasse 21a, 8010 Graz, Austria In the food and pharmaceutical industry, near-infrared spectroscopy is a more and more frequently used tool for process monitoring. This is motivated by its fast and non-invasive nature. Further on, no extensive sample preparation is needed, enabling the use as an online process analytical tool. However, this comes with the drawback of large amounts of correlated data, often influenced by many external factors. Therefore, a lot of effort has to be invested in the correct use of mathematical tools to extract the information of interest. Here we put to use a new prototype NIR spectrometer (by EVK, Raaba, Austria), based on an established chemical imaging system, to enable the reading of several attached probes at the same time. However, even when investigating the same sample, there are slight differences from one probe to another. On the one hand, this is caused by their different field of view; on the other hand, these are to be avoided disturbances, on nominally similar probes. Therefore, it is necessary to identify these disturbances and consider them in the spectral interpretation. This should allow the monitoring of processes at different positions, as well as the simultaneous monitoring of different processes, with one measurement system. In this work, data from the prototype system are presented in use on a pharmaceutical process. It is shown how to overcome some of the appearing difficulties when dealing with a multiprobe system, in order to enable fast and robust process monitoring, and render process control. 111

114 Thu, 15:30-15:50: Coffee break Thu, 15:50-16:30, SR Thu, 15: year record of 236-U/238-U in coral as a step towards establishing 236-U as oceanic tracer Stephan Winkler 1, Peter Steier 1, Jessica Carilli 2 1 University of Vienna, Währinger Straße 17, 1090 Vienna, Austria 2 Australian Nuclear Science and Technology Organization, Lucas Heights, New South Wales 2234, Australia Since uranium is known to behave conservatively in ocean waters, 236-U has great potential in application as oceanic tracer. 236-U (t1/2=23.4ma) was introduced into the oceans by atmospheric nuclear weapon testing with amounts estimates ranging from 700kg to 1500kg. Thus a resulting initial average 236-U/238-U ratio of at least 5e-9 is expected for an oceanic mixed layer depth of 100m. This ratio is significantly higher than the natural pre-nuclear age background, which is expected to be at 1e-14 levels. However, even the elevated ratios of global stratospheric fall-out are beyond the capabilities of ICPMS and TIMS methods. However, the exceptional sensitivity and ultra-low background for 236-U of the Vienna Environmental Research Accelerators Accelerator Mass Spectrometry system allows us to measure down to 1e-13 detection limits. We present a year-by-year record of 236-U/238-U for a Caribbean coral core covering years 1944 to 2006, thus allowing to us put constraints on the oceanic input of 236-U by atmospheric testing. Moreover modelling of the results also demonstrates the capabilities of 236-U as oceanic tracer. 112

115 Thu, 16:10 Stalk-free membrane fusion of cationic lipids via an interdigitated phase Georg Pabst 1, Caroline Lonez 2, Michel Vandenbranden 2, Jacques Jestin 3, Aurel Radulescu 4, Jean-Marie Ruysschaert 2, Thomas Gutberlet 5 1 Austrian Academy of Sciences, Schmiedlstrasse 6, 8042 Graz, Austria 2 Faculte des Sciences, Universite Libre de Bruxelles, CP 206/2, Campus Plaine, Blvd. du Triomphe, 1050 Brussels, Belgium 3 Laboratoire Leon Brillouin, CEA/CNRS, C.E.A Saclay, Gif-sur- Yvette Cedex, France 4 Jülich Centre for Neutron Science, Lichtenbergstrasse 1, Garching, Germany 5 Helmholtz-Zentrum Berlin GmbH, Hahn-Meitner-Platz 1, Berlin, Germany Packaging of DNA is a central concept in gene therapy in order to overcome membrane barriers. One possibility is to use cationic lipids, which may form various aggregate structures when complexed with DNA, due to an intricate interplay of electrostatic interactions (see e.g.[1]). One highly promising lipid candidate is N-t-butyl-N -tetradecyl-3-tetradecylaminopropionamidine (dic14-amidine), which shows high fusion capabilities with target membranes. Interestingly and in contrast to other lipids, fusion of dic14-amidine vesicles is significantly enhanced in the gel phase. Therefore, we have performed a comprehensive X-ray and neutron small-angle scattering as well as dilatometry and ultrasound velocimetry study on dic14-amidine. We found an anomalously thin lamellar fluid phase at high temperatures, which transforms into a loosely packed interdigitated phase below the chain melting transition. Typical fusion pathways via point-like defects (stalks) can therefore be ruled out in order to explain amidine s unusual fusion behavior. Instead, we propose that the loose lipid packing leads to a significant exposure of the hydrophobic lipid core to the aqueous phase, reducing energy penalties from the removal of water during fusion. [1] A.V. Radhakrishnan, S. K. Ghosh, G. Pabst, V. A. Raghunathan, and A. K. Sood, Proc. Natl. Acad. Sci. 109: (2012). [2] G. Pabst, C. Lonez, M. Vandenbranden, J. Jestin, A. Radulescu, J.-M. Ruysschaert, and T. Gutberlet, Soft Matter, (2012), DOI: /c2sm25665g. 113

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117 11 Surfaces, Interfaces and Thin Films (OGD) HS Surfaces, Interfaces and Thin Films Oberflächen, Grenzflächen und dünne Schichten Christian Teichert, Thursday, 20 th September 2012, HS :00-11:00 Time Presenter Title 09:00-09:20 Erminald Bertel Surface Phases on 122 Fe Based Superconductors: An Indication of Charge Density Wave Fluctuations? 09:20-09:40 Bernhard Stöger Scanning Tunneling Microscopy study of single-crystalline Sr 3 Ru 2 O 7 09:40-10:20 Robert Schennach Paper - A Material with Unique Properties 10:20-10:40 Matus Milko Understanding the electronic structure of weakly bound nanohybrid systems 10:40-11:00 David Egger Reliably Modeling the Properties of a Complex Inorganic-Organic Hybrid System 11:00-11:30 Coffee break Thursday, 20 th September 2012, HS :30-15:30 Time Presenter Title 14:30-14:50 Marcus Rennhofer Growth of ZnO nano-rods solar-cell material on ITO investigated by X- Ray-diffraction 14:50-15:10 Franz Schmied Tip-enhanced Raman Spectroscopy challenges and opportunities 15:10-15:30 Herbert Reingruber New advanced microscopic methods for detailed analysis of strong asymmetric microfiltration membranes 15:30-15:50 Coffee break 115

118 Thursday, 20 th September 2012, HS :50-18:00 Time Presenter Title 15:50-16:20 Gregor Hlawacek UHV Helium Ion Microscopy a new tool for surface science? 16:20-16:40 Alexander Volk Deposition of Metal Clusters Formed Inside Superfluid Helium Nanodroplets 16:40-17:00 Martin Denk A novel two-dimensional Cu-tungstate (CuWOx) phase on Cu(110) 17:00-17:20 Mandy Grobosch Organic PCBM field effect transistors: Analysis of the contact properties by combined photoemission spectroscopy and electrical measurements 17:20-17:40 Roland Resel Surface Induced Crystal Structures: Crystal Growth and Structure Solution 17:40-18:00 Daniel Lüftner The electronic structure of pentacene monolayers on Ag(110) and Cu(110) Friday, 21 st September 2012, HS :00-11:00 Time Presenter Title 09:00-09:20 Joongil Jake Choi ZrO 2 ultra-thin films on Pd 3 Zr(0001): Structure and growth of metal clusters 09:20-09:40 Markus Kratzer AFM based electrical investigations on Ge nanodomes on Si(001) 09:40-10:20 Tomáš Šikola In situ observation of the growth of germanium nanofibres Ordered Array of Single Au Adatoms 10:20-10:40 Zbynek Novotny on Fe 3 O 4 (001) with Remarkable Thermal Stability 10:40-11:00 Josef Redinger Strain and structure driven complex magnetic ordering of a CoO overlayer on Ir(100) 11:00-11:30 Coffee break 116

119 Friday, 21 st September 2012, HS :30-13:40 Time Presenter Title 11:30-12:10 Peter Zeppenfeld Microscopy and Spectroscopy of ultrathin organic layers and nanocrystals 12:10-12:30 Eva Reinisch Cs doping of organic semiconducting monolayers: probing the electronic and geometric structure with angle resolved UPS The influence of venting on the island 12:30-12:50 Levent Tümbek size distribution observed for Hexaphenyl on mica 12:50-13:10 Margareta Wagner Growth and structure of Tetraphenylporphyrin on Cu(110)-p(2x1)O 13:10-13:40 Stefan Müllegger STM Studies of Surface-Supported Stable Hydrocarbon Radicals 117

120 Thu, 09:00-11:00, HS Thu, 09:00 Surface Phases on 122 Fe Based Superconductors: An Indication of Charge Density Wave Fluctuations? Erminald Bertel 1, Michael Cordin 1, Peter Amann 2, Alexander Menzel 1, Mikhail Baranov 1, Sebastian Diehl 1, Josef Redinger 3, Cesare Franchini 4 1 University of Innsbruck, Innrain 52a, 6020 Innsbruck, Austria 2 Vorarlberg University of Applied Sciences, Hochschulstrasse 1, 6850 Dornbirn, Austria 3 Vienna University of Technology, Gußhausstrasse 25-25a, 1040 Vienna, Austria 4 University of Vienna, Sensengasse 8/12, 1090 Vienna, Austria On the cleavage planes of 122 Fe based superconductors two different long-range ordered structures can be found, i.e. a (2 1) phase prevalent after cleavage at low temperature and a 2 2 phase found after cleavage at room temperature. The majority of groups attributes these structures to an adlayer of earth alkali metal atoms. The existence of different long-range ordered structures corresponding to the same coverage in different temperature regimes is extremely rare in surface systems and requires an active role of the substrate in the ordering process. The adsorbate system Br/Pt(110) exhibits analogous phases, namely a (2 1)4-Br/Pt(110) structure at T < 50 K and a c(2 2)-Br/Pt(110) structure at room temperature. The phase transition is associated with the removal of a periodic lattice distortion (PLD) and an accompanying charge density wave (CDW) in the substrate as T is increased. At sufficiently low temperature the fluctuating CDW/PLD order parameter is stabilised by the adsorbate in a lock-in type mechanism. A similar mechanism can account for the observations on the 122 Fe pnictide surfaces suggesting the presence of CDW fluctuations at low temperature. Thu, 09:20 Scanning Tunneling Microscopy study of single-crystalline Sr 3 Ru 2 O 7 Bernhard Stöger 1, Zhiming Wang 1, Marcel Hieckel 1,2, Florian Mittendorfer 1, Raimund Podloucky 2, Josef Redinger 1, David Fobes 3, Zhiqiang Mao 3, Michael Schmid 1, Ulrike Diebold 1 1 Vienna University of Technology, Wiedner Hauptstrasse 8-10/134, 1040 Vienna, Austria 2 University of Vienna, Sensengasse 8/7, 1090 Vienna, Austria 3 Tulane University, 2001 Percival Stern Hall, 6400 Freret St, New Orleans, LA, USA Perovskite oxides play an important role as cathodes in solid oxide fuel cells (SOFC) and in catalysis. Investigating surface defects such as oxygen vacancies and the adsorption of relevant molecules helps gaining more insight into the physics behind SOFCs and catalytic processes. Highquality Sr 3 Ru 2 O 7 (SRO) single crystals were grown using the floating zone technique. The SRO samples were cleaved at 150 K under UHV conditions and subsequently investigated by STM at 78 K and 6 K. To determine which species are imaged in STM, doped SRO samples were investigated and STM simulations were performed. Furthermore, we have characterized the defects that are present at the as-cleaved surfaces, and how reactive they are if exposed to CO and O 2. STM shows that CO binds to some defects at the surface and, possibly, also to apical oxygen atoms at the perfect surface. The interaction between the clean surface and CO was also investigated by DFT calculations. This work was supported by the Austrian Science Fund (FWF project F45). 118

121 Thu, 09:40, Keynote Paper - A Material with Unique Properties Robert Schennach 1 1 Graz University of Technology, Petersgasse 16/2, 8010 Graz, Austria Paper is one of the oldest man made materials, which one is using on a daily basis for things like writing, printing, wrapping or carrying goods. However, one hardly stops to think about this quite unique material. Paper has several unique properties due to its very hierarchical structure from the cellulose molecules via the paper fibers up to the paper network. The current view of the surface structure and surface chemistry of paper fibers will be presented, which play an important role in the formation of the bonds between the individual fibers in the paper network. The nature of the fiber - fiber bond in paper is still under discussion, but researchers agree that mechanical interlocking, inter diffusion, hydrogen bonds, Van der Waals bonds and Coulomb interactions do play a role. However, it is not yet clear to which extend these bonding forces play a role in paper strength. In addition, the influence of capillary bridges will be discussed. While it is agreed that they play an important role during bond formation (as paper is simply made by spraying a suspension of paper fibers in water on a sieve and then drying the sheet of paper), it is an open question whether or not capillary bridges still play a role in dry paper. Recent experimental results concerning this questions will be discussed. Thu, 10:20 Understanding the electronic structure of weakly bound nanohybrid systems Matus Milko 1, Claudia Draxl 2, Peter Puschnig 1 1 University of Graz, Universitätsplatz 5, 8010 Graz, Austria 2 Humboldt-Universität zu Berlin, Newtonstraße 15, Berlin, Germany We present an ab initio study on the formation of electronic states at the interface in weakly bound hybrid nanostructures. As an example, we study the polymer poly-para-phenylene embedded in a zig-zag nanotube, for which we vary the diameter up to the limiting case of graphene. It turns out, that besides the anticipated electronic level alignment with respect to the vacuum potential, three additional factors impact the electronic structure of the combined system. First, we observe a difference in the electrostatic potential outside and inside the nanotube, which is associated with its curvature. Second, an interface dipole arises from the charge redistribution within the sub-units. Finally, mutual polarization effects of the polymer and its host are shown to play an important role in the level alignment. We investigate in detail, how these three factors depend on size and spatial arrangement of the constituents, and the fact whether the nanotube is metallic or semiconducting. Based on this knowledge, we propose a simple scheme to predict the nanohybrid s electronic structure from the bands of its constituents alone. 119

122 Thu, 10:40 Reliably Modeling the Properties of a Complex Inorganic-Organic Hybrid System David Egger 1, Victor Ruiz 2, Wissam Al-Saidi 3, Tomas Bucko 4, Alexandre Tkatchenko 2, Egbert Zojer 1 1 Graz University of Technology, Petersgasse 16, 8010 Graz, Austria 2 Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, Berlin, Germany 3 University of Pittsburgh, Pennsylvania 15261, USA 4 Comenius University, mlymska dolina, Bratislaba, Slovakia When different materials align to form hetero-structures, the final electronic properties are often determined by the connecting interface. In nowadays organic-electronic devices, where several semiconductor/metal and semiconductor/semiconductor interfaces are an integral part of common device geometries, controlling these interfaces is not only necessary to maintain device functionality, but might even be exploited towards designing electronic features from the bottom-up. In this presentation, we seek for a microscopic insight into these interfaces and the relevant physical and chemical processes. A prototypical metal-supported organic double-layer system copper phtalocyanine (CuPc) on 3,4,9,10-perylene tetracarboxylic dian-hydride (PTCDA) adsorbed on Ag(111) is investigated by means of semilocal density-functional theory (DFT) based band-structure computations. Including van der Waals (vdw) interactions through PBE+vdWsurf, a recently developed scheme where dispersion-corrected DFT is combined with the Lifshitz-Zaremba-Kohn theory to account for the polarizability within the metallic surface [Phys. Rev. Lett. 108, (2012)], we underline the importance of dispersive interactions and physisorptive bonding at the interfaces in CuPc@PTCDA@Ag(111). Comparing our results to recent experimental data [Phys. Rev. Lett. 108, (2012)], we find very good agreement for adsorption distances and CuPc-induced shifts in the electronic structure of the PTCDA/Ag(111) interface. These findings are rationalized by vdw-interactions, thus highlighting their consideration as being imperative for a microscopic understanding and quantitatively accurate modeling of interfaces in complex metal-organic systems. Thu, 11:00-11:30: Coffee break 120

123 Thu, 14:30-15:30, HS Thu, 14:30 Growth of ZnO nano-rods solar-cell material on ITO investigated by X-Ray-diffraction Marcus Rennhofer 1, Herwig Peterlik 1, Johanna Akbarzadeh 1, Erhard Schafler 1, Stephan Abermann 2, Antun Peić 2, Theodorus Dimopoulos 2, Hubert Brueckl 2 1 University of Vienna, Strudlhofgase 4, 1090 Vienna, Austria 2 Austrian Institute of Technoloy, Donau-City-Strasse 1, 1220 Vienna, Austria ZnO is a wide bandgap ( 3.2 ev) semiconductor, crystallizing in the hexagonal wurtzite form. It is natively n-type doped and possesses favorable properties such as high transparency, high electron mobility and strong room temperature-luminescence. In the last years great interest was attracted towards ZnO nanostructures such as nanorods (NR). ZnO NR arrays have been investigated for various applications in a number of emerging areas one of them solar cells. This work focuses on the controlled electrochemical growth of ZnO NRs on Sn-doped In 2 O 3 (ITO)-coated glass substrates. The structural development of NRs on the initial stages of growth was analyzed by different XRD techniques. The formation of the crystalline ZnO-structure could be measured using WAXS-geometry. The WAXS measurements show that ZnO-structure peaks of the ZnO-NR on the ITO substrate occur for deposition times longer than 1 min. Peaks of the directions (100), (002), (101), (102) and (110) could be identified. The formation of the (002) peak being the favorable direction for producing well aligned ZnO-NR is the strongest pronounced. The formation of the single peaks is linear in time. There was no shielding of the ITO peaks visible. The FWHM of all peaks was nearly stable for all deposition steps as was the position of the peaks. The results imply that the use of preparation techniques known from chemical industry and industrial scale allow to manufacture cheap and efficient solar cells. Thu, 14:50 Tip-enhanced Raman Spectroscopy challenges and opportunities Franz Schmied 1,2, Tatiana Perova 1, Silvia Giordani 1, Paula Colavita 1, Robert Schennach 2,3 1 University of Dublin, Trinity College Dublin, College Green, Dublin 2, Ireland 2 CD-Laboratory for Surface Chemical and Physical Fundamentals of Paper Strength, Graz University of Technology, Petersgasse 16/2, 8010 Graz, Austria 3 Institute of Solid State Physics, Graz University of Technology, Petersgasse 16/2, 8010 Graz, Austria Tip-enhanced Raman Spectroscopy (TERS) is a new technique that combines the scanning capabilities of atomic force microscopy (AFM) with Raman spectroscopy on the nanometer scale. Here, a metal-coated AFM tip acts as nanoantenna, which enhances the weak Raman signal of the Near Field by orders of magnitude and allows for overcoming the optical diffraction limit. A crucial role in reaching optical resolution down to 10nm plays the nanoantenna. Here, we present techniques (vapor-coated, electroless chemical deposition) to metal-coated commercially available AFM probes suitable for TERS measurements on opaque samples in upright configuration. Further, we address interpretation of signal blinking in TERS spectra that belongs to carbonaceous contamination and live-time issues of the used coating. The financial support of Mondi, Science Foundation Ireland, and the Austrian Federal Ministry of Economy, Family and Youth and the National Foundation for Research, Technology and Development is gratefully acknowledged. 121

124 Thu, 15:10 New advanced microscopic methods for detailed analysis of strong asymmetric microfiltration membranes Herbert Reingruber 1, Armin Zankel 1, Peter Pölt 1 1 Graz University of Technology, Steyrergasse 17, 8010 Graz, Austria Filtration is a very essential technology in various fields of science. Concerning the water shortage of many countries the importance of filtration technology gets clear. For many of these applications microfiltration membranes are used. Modern filtration membranes are high tech products delivering high flux rates compared with well defined retention properties, due to their special asymmetric pore structure. For membrane optimization new techniques of characterizing them are essential. This work shows the development and results of two new characterization methods based on electron microscopic methods. One method allows a three dimensional (3D) reconstruction of the membrane structure. This was accomplished by automated serial sectioning and subsequent imaging of the membrane cross-section. The achieved image stack was used for 3D reconstructions. From the reconstruction, parameters like the inner membrane surface, the local porosity or by means of fluid simulations the water was flux calculated. The obtained data are in agreement with experimental data. However the properties of the pore walls (whether they are hydrophilic or hydrophobic) cannot be measured with this method. Therefore the microscopic membrane structure was studied additionally under wet conditions. For this aim the microscope sample chamber can be used as micro- laboratory in order to establish environmental conditions. By cooling of the membrane water can condensate and the interaction of the pores with water can be observed. The number and size distribution of wet and dry pores during such a wet- drying experiment can be obtained. Thu, 15:30-15:50: Coffee break 122

125 Thu, 15:50-18:00, HS Thu, 15:50, Invited UHV Helium Ion Microscopy a new tool for surface science? Gregor Hlawacek 1, Vasilisa Veligura 1, Raoul van Gastel 1, Harold Zandvliet 1, Bene Poelsema 1 1 University of Twente, Carré CR 2.213, P.O. Box 217, 7500 AE Enschede, Netherlands Helium Ion Microscopy (HIM) is a new tool that allows high resolution imaging of a wide range of materials. The fact that the technique is not limited to conductive materials and the many different contrast mechanisms make it a promising tool for nano structure research. HIM has demonstrated unprecedented resolution both on conductive and isolating materials. It is wellknown for its high surface sensitivity when using secondary electrons generated by the impinging ions. Chemical sensitivity is possible via the backscattered He. Both qualitative element contrast maps as well as quantitative localized Rutherford Backscattering are possible. In addition Ionoluminescence allows to obtain information on the bandstructure and defects, such as color centers, by analyzing the emitted photons. The extension of the method to UHV conditions and the high surface sensitivity allow to investigate surface and interface properties with a high spatial resolution. Investigated systems of interest to surface science include self assembled monolayers and thin films of conjugated molecules. However, I will also show results on the visualization of buried interfaces and demonstrate how crystallographic information can be obtained. In all cases the relevant contrast mechanisms will be discussed. This research is supported by the Dutch Technology Foundation STW, which is the applied science division of NWO, and the Technology Programme of the Ministry of Economic Affairs. Thu, 16:20 Deposition of Metal Clusters Formed Inside Superfluid Helium Nanodroplets Alexander Volk 1, Markus Koch 1, Evelin Fisslthaler 2, Werner Grogger 2, Wolfgang Ernst 1 1 Graz University of Technology, Petersgasse 16, 8010 Graz, Austria 2 Graz University of Technology, Steyrergasse 17/III, 8010 Graz, Austria We have recently successfully synthesized silver (Ag n) and chromium (Cr n) nanoclusters inside superfluid helium nanodroplets (He n) and deposited these metal clusters on an amorphous carbon (a-c) surface. Transmission electron microscope (TEM) images shall be presented as well as microbalance measurements. During the past decade, He n turned out to offer a unique experimental environment, combining both a least perturbing superfluid quantum matrix at 0.4 K and a well defined local confinement, given by the droplet radius of a few nanometres. Therefore these nanocryostats are well suited for the synthesis of metal nanoclusters. The first surface deposition of nanoclusters (Ag n) assembled inside He n has only recently been demonstrated [1]. We were now able to deposit Cr n using the same method. The comparison of Ag n and Cr n measurements indicates a strong oxidation of Cr n, while this is not the case for Ag n. In the next step we want to form bimetallic core shell structures in Hen by sequential particle pickup. Due to the formation process in the favourable superfluid environment, we expect a radial symmetric structure of these bimetallic nanostructures, where a shell of silver atoms encloses and therefore passivates the chromium core. Besides the TEM images and microbalance investigations, we seek to present more detailed chemical information obtained from X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDX) and electron energy loss spectrometry (EELS) measurements. [1] E. Loginov, L. F. Gomez, and A. F. Vilesov; J. Phys. Chem. A 115, (2011) 123

126 Thu, 16:40 A novel two-dimensional Cu-tungstate (CuWOx) phase on Cu(110) Martin Denk 1, David Kuhness 1, Margareta Wagner 1, Svetlozar Surnev 1, Fabio Negreiros 2, Luca Sementa 2, Giovanni Barcaro 2, Alessandro Fortunelli 2, Falko Netzer 1 1 University of Graz, Universitätsplatz 5, 8010 Graz, Austria 2 CNR-IPCF, Istituto per i Processi Chimico-Fisici del CNR, I-56124, Pisa, Italy We explore the feasibility to fabricate W-oxide nanostructures on metal surfaces via selfassembly and condensation of (WO 3 ) 3 clusters, deposited directly from the gas phase: here we report the formation of a novel two-dimensional Cu-tungstate CuWOx phase on Cu(110). A beam of (WO 3 ) 3 cluster molecules, formed by sublimation of WO 3 powder at C in a thermal evaporator, has been directed onto a Cu(110)2 1-O surface oxide at low temperature and the surface has been annealed subsequently at 600 K. At low temperature (<15 K) the (WO 3 ) 3 clusters adsorb in intact molecular form, albeit in a somewhat distorted cluster geometry. Upon heating to 600K, the (WO 3 ) 3 molecules dissociate and react with the Cu-O(2 1) surface oxide, forming a wetting monolayer with a well ordered incommensurate structure. The latter has been structurally characterized by high-resolution STM imaging and LEED. The chemical nature and electronic structure of this novel 2-D W-O-Cu layer has been investigated by high-resolution XPS core level spectroscopy, NEXAFS, and valence band spectra. The unusually sharp W 4f core level spectra, the specific NEXAFS fingerprint and the evolution of the valence band all suggest that this 2-D W surface oxide is of a Cu-tungstate CuWOx type. Density functional calculations are in progress to help elucidating the physical and chemical nature of this unusual surface oxide phase. Thu, 17:00 Organic PCBM field effect transistors: Analysis of the contact properties by combined photoemission spectroscopy and electrical measurements Mandy Grobosch 1, Ingo Hörselmann 2, Susanne Scheinert 2, Martin Knupfer 3, Gernot Paasch 3 1 University of Graz, Universitätsplatz 5, 8010 Graz, Austria 2 Technische Universität Ilmenau, Ehrenbergstrasse 29, Ilmenau, Germany 3 IFW Dresden, Helmholtzstraße 20, Dresden, Germany Source/drain contacts in OFETs based on a solution prepared modified PCBM were characterized by combined X-ray and ultra violet photoemission spectroscopy (XPS, UPS) and electrical measurements of the OFET. Thereby the sample preparation for the different measuring principles has been realized in parallel, differing only in the layer thickness of the polymer. By means of UPS a reduced work function could be demonstrated for differently prepared, sputtered, and as-received Au and Al contacts in agreement with previous publications [1]. On top of the Al contacts a natural AlOx layer could be identified. For both the PCBM/Au and PCBM/Al systems UPS a hole injection barrier of 1.8 ev has been determined by UPS in agreement to previous published data. Considering the energy gap of 2.0 ev [2] for PCBM the electron injection barrier would be the same of 0.2 ev. In addition, the metal/organic interface Au/PCBM/Al has been investigated by means of combined XPS and UPS. The deposition of Au on the PCBM films results in a growth of gold clusters and a non-closed Au film. In contrast to the identical hole injection barriers for Au and Al bottom contacts as following from UPS, the OFET currents differ by more than two orders of magnitude. A possible origin of this striking discrepancy will be presented. [1] M. Grobosch et al., Adv. Mater. 19 (2007) 754. [2] Z.-L. Guan et al., Organic Electronics 11 (2010)

127 Thu, 17:20 Surface Induced Crystal Structures: Crystal Growth and Structure Solution Roland Resel 1, Armin Moser 1, Ingo Salzmann 2, Raphaele Della Valle 3, Michele Sferrazza 4, Yves Geerts 4 1 Graz University of Technology, Petersgasse 16, 8010 Graz, Austria 2 Humboldt-Universität zu Berlin, Newtonstrasse 15, Berlin, Germany 3 Universitá di Bologna, Via Zamboni, Bologna, Italy 4 Université Libre de Bruxelles, Campus de la Plaine, 1050 Bruxelles, Belgium A large number of organic semiconductors exhibits polymorphism and well-known phenomena are specific crystallographic phases which are present exclusively in thin films. Such crystallographic phases are often denoted as surface induced phases, since the presence of a surface during the crystallisation is of primary importance for their formation. In general, such thin-film polymorphs do not exist as macroscopic free standing single crystals. A number of surface induced crystal structures of conjugated molecules have been solved during the last years, examples are in particular application relevant molecules like pentacene. Within the talk the crystallisation behaviour of different calamitic conjugated molecules will be described: pentacene, sexithiophene and dihexyl-terthiophene. It is found that surface induced phases are formed by various techniques of thin film preparation. Solution based methods as well as physical vapour deposition can yield surface induced phases. Important parameters for preparation are the type of surface, the evaporation rate (or deposition rate) of the solvent during the thin film preparation and the temperature of the substrate during the crystallisation process. Similarities and differences in the molecular packing between known crystal structures and surface induced phases will be discussed. Of particular importance for the formation of surface induced crystal structures is the formation of the first molecular monolayer on a surface. Based on the experimental observations, thermodynamic issues will be finally discussed, especially if surface induced crystal structures are metastable phases or thermodynamically stable phases due to the presence of a surface. Thu, 17:40 The electronic structure of pentacene monolayers on Ag(110) and Cu(110) Daniel Lüftner 1, Thomas Ules 1, Michael Ramsey 1, Georg Koller 1, Peter Puschnig 1 1 University of Graz, Universitätsplatz 5, 8010 Graz, Austria We present a combined theoretical and experimental study of ordered monolayers of pentacene (5A) on Ag(110) and Cu(110). Theoretically, we have performed ab-initio calculations within the framework of density functional theory for the adsorbed monolayers and analyzed their electronic structure in terms of projected density of states and photoemission cross sections within the planewave final-state approximation. In addition, we have undertaken GW-calculations for isolated pentacene, bulk pentacene and a freestanding layer of pentacene to emphasizing that G 0 W 0 corrections greatly improve DFT band gaps. Thereby, we also demonstrate that the G 0 W 0 gaps are strongly dependent on the local environment of the pentacene molecule, an effect which is absent in DFT. Experimentally, the valence electronic structure of pentacene monolayers are studied by angle-resolved photoemission spectroscopy. Thereby, an extensive data set of the photocurrent I as a function of parallel momenta (k x,k y) and binding energy E b has been obtained. This data cube is compared with simulated momentum maps of various pentacene molecular orbitals of an isolated molecule. Thereby, we can unambiguously identify four molecular states between the Fermi level and the top of the Ag d-band. By including the substrate in momentum map calculations, we are able to detect possible modifications of molecular states due to the interaction with the substrate. On comparing monolayer on Ag(110) and Cu(110), we find that 5A is oriented parallel to the substrate [1-10]-direction on Cu(110) and perpendicular to it on Ag(110). 125

128 Fri, 09:00-11:00, HS Fri, 09:00 ZrO 2 ultra-thin films on Pd 3 Zr(0001): Structure and growth of metal clusters Joongil Jake Choi 1, Ulrike Diebold 1, Michael Schmid 1 1 Vienna University of Technology, Wiedner Hauptstrasse 8-10/134, 1040 Vienna, Austria Despite its importance in many areas of industry such as catalysis, fuel cell technology and microelectronics, the surface structure and physical properties of ZrO 2 are yet not well understood. We report a STM, AES and XPS study of ultra-thin ZrO 2 films prepared by oxidation of a Pd 3 Zr(0001) crystal. A clean Pd 3 Zr(0001) surface with wide terraces ( nm) was obtained by the Ar sputtering and annealing at 900 C. A homogeneous ZrO 2 film was grown by 30 minutes of oxidation of Pd 3 Zr(0001) at 450 C in an oxygen pressure of Torr and annealing at 900 C for 10 minutes in UHV. The film has a fluorite trilayer (O-Zr-O) structure with an in-plane lattice constant of ± nm and a ( 43 43)R7.6 superstructure cell with respect to the substrate (a subst. = nm). Electron bombardment results in oxygen vacancies with a desorption cross-section of 170 pm 2. When depositing small amounts of Au, we find single Au ad-atoms and clusters of various sizes (1 1.5 nm). The single Au atoms disappear at 470 K and larger clusters diffuse through the oxide to substrate at > 600 K. Pd clusters behave similar to Au, but diffuse through the oxide at a lower temperature ( > 500 K). Fri, 09:20 AFM based electrical investigations on Ge nanodomes on Si(001) Markus Kratzer 1, Christian Prehal 1, Maria Rubezhanska 2, Yury Kozyrev 2, Sergey Kondratenko 3, Christian Teichert 1 1 Montanuniversität Leoben, Franz-Josef-Strasse 18, 8700 Leoben, Austria 2 O. O. Chuiko Institute of Surface Chemistry, 17 Generala Naumova St., 03164, Kyiv, Ukraine 3 Taras Shevchenko National University of Kyiv, Physics Dept. pr. Acad. Glushkova 2, Kyiv, Ukraine The potential application of nanodots, nanowires, and nanodomes (NDs) in optoelectronics and photovoltaics has triggered intensive research on such low-dimensional nanostructures. In this work, we report on the electrical characterization of individual Ge nanodomes utilizing conductive atomic force microscopy (C-AFM), and photoconductive AFM (PC-AFM. The Ge ND samples were prepared by means of molecular beam epitaxy (MBE) on Si(001) substrates under ultra-high vacuum (UHV) conditions. Facetted islands exhibiting {113} and { } facets could be identified via AFM topography measurements. The AFM based electrical characterizations were performed under ambient conditions in dark and under illumination. Two-dimensional current maps revealed a higher conductivity of the NDs compared to the surrounding. Conductivity variations within single NDs could be observed, which will be discussed with respect to Ge ND facets an silicon intermixing. Local current-to-voltage (IV) measurements on top of individual NDs revealed a dependence of the IV characteristics on the ND size. Additionally, the generation of a photovoltage due to light exposure has been observed. Support in the framework of the Ukrainian-Austrian projects M/ and UA-11/2009 is acknowledged. 126

129 Fri, 09:40, Keynote In situ observation of the growth of germanium nanofibres Tomáš Šikola1, Miroslav Kolíbal 2 1 Brno University of Technology, Technická 10, Brno, Czech Republic 2 Brno University of Technology, Technická 2, Brno, Czech Republic Although several routes for fabrication of NWs exist, the vapor-liquid-solid (VLS) process is the most versatile approach in the production of group IV and III-V semiconductor NWs. In this method the metallic droplet has to be fed with the growth material, which is supplied in the form of gas molecules (CVD) or an atomic beam (PVD). The CVD method is used more frequently in fabrication of NWs than the PVD one, however, the latter method is more useful for in situ monitoring of the growth as its operation pressure is lower and, hence, more characterization techniques can be applied. In the contribution, in situ monitoring of 110 oriented Ge nanowire growth by SEM will be discussed. It will be shown that germanium nanowires can be grown by a vapor-liquid-solid process in 110 directions both on Ge(100) and Ge(111) substrates if very low supersaturation in the collector droplet is ensured. This is also supported by in-situ observations of nanowire kinking towards 111 direction occurring more frequently at higher evaporation rates. Further, it will be demonstrated that the hexagonal cross-section of germanium nanowires grown in the 110 direction by physical vapor deposition is a consequence of minimization of surface energy of the collector droplet. If the droplet is lost or solidified, two {001} sidewall facets are quickly overgrown and the nanowire exhibits a rhomboidal cross-section. This process can be controlled by switching between the liquid and solid state of the droplet, enabling the growth of nanowires with segments having different cross-sections. These experiments will be supported by a theoretical model. In the end basic principles of the fabrication of regular arrays of nanowires by the guided growth of metallic droplets on substrates pre-patterned by focused ion beam will be discussed. Fri, 10:20 Ordered Array of Single Au Adatoms on Fe 3 O 4 (001) with Remarkable Thermal Stability Zbynek Novotny 1, Giacomo Argentero 1, Zhiming Wang 1, Michael Schmid 1, Ulrike Diebold 1, Gareth Parkinson 1 1 Vienna University of Technology, Wiedner Hauptstrasse 8-10/134, 1040 Vienna, Austria We present a scanning tunneling microscopy investigation of gold deposited at the magnetite Fe 3 O 4 (001) surface at room temperature. This surface forms a reconstruction with c(2 2) symmetry [1], where pairs of Fe and neighboring O ions are slightly displaced laterally, forming undulating rows with narrow and wide adsorption sites. At fractional monolayer coverages, single Au adatoms adsorb exclusively at the narrow sites, with no significant sintering up to annealing temperatures of 400 C[2]. The strong preference for narrow site is possibly related to charge and orbital ordering within the first subsurface octahedral layers of the reconstructed Fe 3 O 4 (001) surface[3]. Because of their high thermal stability, the ordered Au atoms at Fe 3 O 4 (001) reconstructed surface should provide useful insights into the chemical reactivity of single atomic species. This material is based upon work supported as part of the Center for Atomic-Level Catalyst Design, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number #DE-SC [1] Pentcheva, R. et al. Phys. Rev. Lett 2005, 94, [2] Novotny, Z. et al., Phys. Rev. Lett. 108, (2012) [3] Lodziana, Z. Phys. Rev. Lett. 2007, 99,

130 Fri, 10:40 Strain and structure driven complex magnetic ordering of a CoO overlayer on Ir(100) Josef Redinger 1, Florian Mittendorfer 1, Michael Weinert 2, Raimund Podloucky 3 1 Vienna University of Technology, Wiedner Hauptstrasse 8-10/134, 1040 Vienna, Austria 2 University of Wisconsin Milwaukee, P.O. Box 413, 2200 E. Kenwood Blvd., Milwaukee, WI , USA 3 University of Vienna, Sensengasse 8/7, 1090 Vienna, Austria The magnetic ordering in the ultrathin c(10 2) CoO(111) film supported on Ir(100) has been investigated on the basis of ab-initio calculations. A close relationship between the local structural properties of the oxide film and the induced magnetic order was found, which leads to alternating ferromagnetically and anti-ferromagnetically ordered CoO segments. While the local magnetic order is directly related to the geometric position of the Co atoms, the mismatch between the CoO film and the Ir substrate leads to a complex long-range order of the oxide. Fri, 11:00-11:30: Coffee break 128

131 Fri, 11:30-13:40, HS Fri, 11:30, Keynote Microscopy and Spectroscopy of ultrathin organic layers and nanocrystals Peter Zeppenfeld 1, Lidong Sun 1, Thorsten Wagner 1, Johannes Gall 1, Daniel Queteschiner 1, Michael Hohage 1 1 Johannes-Kepler-Universität, Altenbergerstrasse 69, 4040 Linz, Austria We report on the investigation of organic layers, thin films and nanocrystals using optical spectroscopy (RDS and SDR), Photo Emission Electron Microscopy (PEEM) and Fluorescence / Laser Scanning Confocal Microscopy (FM/LSCM). The combination of these methods enables us to monitor the growth in situ (RDS/SDR, PEEM) and to explore the correlation between the structure and morphology of the organic films with the electronic and optical properties at a microscopic scale (PEEM, FM/LSCM). Exploiting the polarization dependence of the light in RDS, PEEM and FM allows to determine the orientation of the molecules and to identify structural phase transitions. STM and LEED provide supplementary information on the arrangement of the molecules on the surfaces, whereas operating the PEEM with a He UV-lamp allows recording local UPS spectra from the grown films and from individual nanocrystals. Examples will be shown for sexithiophene (6T) and porphyrins on different single crystalline metal surfaces or mica. Fri, 12:10 Cs doping of organic semiconducting monolayers: probing the electronic and geometric structure with angle resolved UPS Eva Reinisch 1, Thomas Ules 1, Georg Koller 1, Peter Puschnig 1, Markus Ostler 2, Stephen Berkebile 1, Thomas Seyller 2, Michael Ramsey 1 1 University of Graz, Universitätsplatz 5, 8010 Graz, Austria 2 University Erlangen Nürnberg, Erwin-Rommel-Strasse 1, Erlangen, Germany Cesium-deposition on ordered organic semiconducting thin films induces changes in the electronic structure and geometric orientation of the molecules. The current investigation is focused on rodlike Sexiphenyl (6P) and Pentacene (5A) molecules adsorbed on Ag(110) and Cu(110) substrates. In an undoped 6P monolayer on Cu(110), we observe flat lying molecules with the LUMO being filled by hybridisation with the surface. Upon Cs deposition first the molecules are tilted and decoupled from the surface, thus the LUMO is emptied. Further Cs deposition subsequently leads to electron charge transfer from the alkali metal to the molecular orbitals, filling first the LUMO, then LUMO+1, with increasing amounts of Cs. In contrast, in an undoped 6P monolayer on Ag(110) the LUMO is empty. Upon Cs deposition the 6P molecules on Ag(110) are doped similar to 6P on Cu(110). Significantly, prior to charge transfer doping, the initial Cs exposure azimuthally reorients the molecules of the 6P and 5A monolayer on Ag(110) from perpendicular to parallel to the substrate corrugation. This contrasts to Cu(110) where both molecules lie parallel to the Cu-rows before and after Cs deposition. This suggests a strong influence of the Cs atoms on the molecule-substrate bonding. The results will be discussed in the light of comparison between the experimental band (E, k) and momentum map (k x, k y) of ARUPS with DFT calculations. This work is supported by the Austrian Science Fund (FWF), projects P21330-N20 and P N

132 Fri, 12:30 The influence of venting on the island size distribution observed for Hexaphenyl on mica Levent Tümbek 1, Christoph Gleichweit 1, Karin Zojer 1, Adolf Winkler 1 1 Graz University of Technology, Petersgasse 16, 8010 Graz, Austria A frequently observed feature in the growth of para-hexaphenyl on freshly cleaved mica is the appearance of a bimodal island size distribution. In this case long needle-like islands, composed of lying molecules, are embedded in a sea of small clusters. Recently, it has been shown that the modification of the mica surface by Ar + ion sputtering, or by the pre-adsorption of carbon or potassium, leads to a different growth behavior. Now the islands are of dendritic shape, composed of standing molecules. Surprisingly, again a bimodal growth mode can be observed. We have re-examined both growth scenarios in detail, using in-situ thermal desorption spectroscopy (TDS) and ex-situ atomic force microscopy (AFM). We found strong evidence that in both cases the small crystallites are caused by a dewetting process, which takes place when the in-vacuo grown films are exposed to air for the ex-situ AFM investigations. This was discovered when TD spectra were taken before and after venting the vacuum chamber. The very different origin of the two sets of islands is also constituted in a very different density, morphology and size distribution of the islands. The phenomenon of subsequent venting induced nucleation could be successfully described by Kinetic Monte Carlo (KMC) simulations. The result of these simulations was that about seven molecules constitute the critical island size. Fri, 12:50 Growth and structure of Tetraphenylporphyrin on Cu(110)-p(2 1)O Margareta Wagner 1, Sina Gusenleitner 1, Tatjana Djuric 2, Stephen Berkebile 1, Roland Resel 2, Michael Ramsey 1, Falko Netzer 1 1 University of Graz, Universitätsplatz 5, 8010 Graz, Austria 2 Graz University of Technology, Petersgasse 16, 8010 Graz, Austria Tetraphenylporphyrin (H 2 TPP) has been grown on Cu-O and previously investigated electronically and structurally by LEED, UPS, NEXAFS and XRD (ex-situ). Surprisingly the same surface structure has been found for both the monolayer and thick film, exhibiting the rather dilute H2TPP(5 10 3) plane. Whereas the narrow spacing and stacking of the layers in the bulk phase still lead to a dense thick film, the monolayer has been assumed to consist of a single H 2 TPP(5 10 3) layer only. However, this would be rather unusual, as porphyrines have been reported to form dense packed monolayers on various surfaces. In this LT-STM work the true structure of the H 2 TPP monolayer has been revealed. It could be demonstrated, that two H 2 TPP(5 10 3) planes merge into a commensurate single dense layer, which is stable due to the strong interaction with the Cu-O surface, and provides an excellent template for crystalline film growth. This work has been supported by the by the Austrian Science Foundation (FWF) within the National Research Network Interface Controlled and Functionalized Organic Films and the ERC Advanced Grant SEPON. 130

133 Fri, 13:10, Invited STM Studies of Surface-Supported Stable Hydrocarbon Radicals Stefan Müllegger 1, Mohammad Rashidi 1, Michael Fattinger 1, Reinhold Koch 1 1 Johannes-Kepler-Universität, Altenbergerstrasse 69, 4040 Linz, Austria Stable free radicals can be stored and investigated under ambient conditions, which makes them desirable for applications as polarizing agents or novel magnetic materials as well as suitable model systems for investigating sp2 magnetism in reduced dimensions. We have studied the stable all-organic spin-1/2 radical, α,γ-bisdiphenylene-β-phenylallyl (BDPA), adsorbed on a weakly interacting metal support by low-temperature scanning tunneling microscopy (LT- STM). We report on the structure, self-assembly, frontier orbital electronic and magnetic properties, and radical-radical interactions at the atomic-scale. 131

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135 12 Careers in Physics (PIE) HS PIE, Phsics-Industry-Energy PIE, Physik-Industrie-Energie Doris A. Steinmüller-Neth, Thursday, 20 th September 2012, HS :00-14:30 Time Presenter Title 13:00-13:15 Doris Steinmüller-Nethl Industrial Research and gender aspects future for physicists in Europe? 13:15-13:30 Jochen Kraft Herausforderungen in der Chipentwicklung für die industrielle Fertigung Beschäftigungsmöglichkeiten für 13:30-13:45 Martin Zimmerling Physiker in der Medizintechnik- Industrie 13:45-14:00 Gerhard Murer Careers for Physicists in the Analytical Instruments Industry 14:00-14:15 Josef Siess Wie man Berufung zum Beruf macht 133

136 Thu, 13:00-14:30, HS Thu, 13:00 Industrial Research and gender aspects future for physicists in Europe? Doris Steinmüller-Nethl 1 1 KOMET RHOBEST GmbH, Exlgasse 20a, 6020 Innsbruck, Austria Industry has a leading role in research, innovation and development. European companies need experts and scientists to boost their innovation and competitiveness. Physicists can fulfill these requirements. Industrial research opens the possibility to develop innovative technologies and products for the benefit of humankind. Interdisciplinarity and diversity are key factors for success. In this presentation the female physicist Doris Steinmüller-Nethl, will report about the challenges of her profession, hurdles she was confronted with and her passion for technology. This short glimpse into promising career options in industrial research should give an impetus for young physicists to trust and develop their talents and realize their opportunities. Thu, 13:15 Herausforderungen in der Chipentwicklung für die industrielle Fertigung Jochen Kraft 1 1 AUSTRIAMICROSYSTEMS AG, Schloss Premstätten, 8141 Unterpremstätten, Austria Jochen Kraft absolvierte ein Diplom-Physik Studium an der Ruprecht-Karls Universität in Heidelberg und promovierte an der Karl-Franzens Universität Graz im Gebiet Oberflächen- und Halbleiterphysik. Im Anschluss war er in der Chip Fertigung bei MICRONAS AG (Freiburg) als Defekt-Ingenieur beschäftigt. Seit 13 Jahren arbeitet er in der Forschungs- und Entwicklungsabteilung von ams AG (früher: austriamicrosystems). ams ist ein führender Anbieter von Analog-Lösungen im Bereich Power Management, Sensor und Sensor-Schnittstellen und Wireless. Das Schaltungsdesign, die Fertigung und der Chip Test ist bei ams unter einem Dach vereint. Dr. Kraft zeigt einige High-Lights aus seiner Entwickler-Tätigkeit bei ams. Insbesondere die neueren Aktivitäten im Bereich 3D Integration und Si-Durchkontakte werden vorgestellt. Die 3D Technologie ermöglicht das Stapeln von Chips, z.b. die Herstellung eines Chips mit einem Sensor auf der einen Seite und der CMOS-Auswerteschaltung auf der anderen Seite. Der Signaltransfer durch den Chip findet mit Durchkontakten statt. Auf diese Weise werden Verdrahtungen vermieden, die zeitverzögernd wirken und relativ viel Platz benötigen. 134

137 Thu, 13:30 Beschäftigungsmöglichkeiten für Physiker in der Medizintechnik-Industrie Martin Zimmerling 1 1 Med-El Elektromedizinische Geräte GmbH, Fürstenweg 77a, 6020 Innsbruck, Austria Forschung und Entwicklung werden in der Medizintechnik auch in Zukunft großgeschrieben werden, um neue Entwicklungen im Gesundheitssystem zu unterstützen und dieses und weiterhin finanzierbar zu halten. Daraus ergeben sich viele Betätigungsfelder auch für Physiker. Neben vielfältigen Herausforderungen im Forschungs- und Entwicklungsbereich finden sich auch im Produktmanagement, in der Qualitätssicherung, im Zulassungsbereich sowie im Patentwesen spannende und interessante Aufgabenbereiche. Martin Zimmerling leitet als Physiker die Implantatentwicklung des weltweit tätigen österreichischen Cochleaimplantat-Herstellers MED-EL. Er wird über seine Berufserfahrungen in der Medizintechnik berichten. Junge Physiker erfahren in dieser Präsentation auch, welche Fähigkeiten und Zusatzqualifikationen einen Einstieg und erfolgreiches berufliches Weiterkommen in der Medizintechnik erleichtern. Thu, 13:45 Careers for Physicists in the Analytical Instruments Industry Gerhard Murer 1 1 Anton Paar GmbH, Ankerstrasse 6, 8054 Graz, Austria The Analytical Instruments Industry is expected to have a sales volume of 45 Billion US$ in 2012 and employs some people worldwide. The industry and the company the presenter works for are briefly introduced. Of the employed in the industry a considerable number is physicists. The presentation highlights career opportunities for physicists in the industry, in particular in the areas of research and technology development, product development, product management as well as sales. Thu, 14:00 Wie man Berufung zum Beruf macht Josef Siess 1 1 Europäisches Service für Personalvermittlung und Unternehmensgründung, Paulanergasse 15/2, 1040 Wien, Austria Ausgebildete Physiker und Physikerinnen nehmen verstärkt wichtige Managementaufgaben in großen Unternehmen, Konzernen und in der Politik wie auch als Forscher in ihren ureigensten Disziplinen wahr. Welche weiteren hard und soft skills von Unternehmungen und Organisationen gefragt und gefordert werden, wenn Spitzenpositionen besetzt werden, werden in diesem Vortrag angesprochen und an Beispielen gezeigt. Was junge Physiker und Physikerinnen für ihre eigene Karriereplanung beachten sollen, welche Zusatzqualifikationen oder Nischen (Spezial-) Kenntnisse außerhalb der wissenschaftlichen Uni-Laufbahn weiterhin nachgefragt sein werden, werden in diesem kurzen Vortrag beleuchtet und sollen Mut machen, auch abseits der Physiklaufbahn Bewerbungen gezielt zu platzieren. Wie man Berufung zum Beruf macht. 135

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139 13 Posters Wednesday, 19 th September :45-20:00 AMP Poster-ID Presenter Title POS-01 Naveed Anjum Experimental Investigations of the Hyperfine Structure of 143 Nd + Spectral lines using Collinear Laser Ion Beam Spectroscopy POS-02 Birgit Brandstätter An ion-photon interface mediated by a cavity POS-03 Michaela Ellmeier Omni-directional magnetic field measurement by means of the Coupled Dark State Magnetometer (CDSM) POS-04 Simon Eschlböck-Fuchs Influence of sample temperature on the dynamics and emission line intensities of laser-induced plasma POS-05 Marcelo Goulart Electron driven chemistry close to 0 K Efficient wave function simulations in POS-06 Sebastian Krämer nonlinear quantum optics using an adaptive coherent state basis POS-07 Michael Niedermayr In situ ion-trap fabrication apparatus for low ion-heating rates POS-08 Matthias Schreitl Towards a nuclear clock with Thorium

140 Wednesday, 19 th September :45-20:00 FAKT Poster-ID Presenter Title POS-09 Stefan Brunner New Approaches for Improvement of Time-of-Flight PET POS-10 Gunther Cronenberg qbounce: Ein Frequenzstandard für Gravitationsspektroskopie POS-11 Jacqueline Erhart Momentum Analysis in PERC POS-12 Philip Haiden Design of the Magnetic Shielding for PERC POS-13 Katharina Isepp Strangeness Production in p-p Collisions at FOPI POS-14 Michael Klopf Proton Spectroscopy with PERC POS-15 Wolfgang Lucha Local-Duality QCD Sum Rules for Pseudoscalar-Meson Form Factors POS-16 Martin Martschini Investigations of negative ion formation in Middleton type ion sources POS-17 Martin Moser Elektronen-Energie-Detektion für PERC POS-18 Thomas Potocar A new very-large Perfect Crystal Neutron Interferometer POS-19 Babak Rahbaran Global Trigger Upgrade project for the CMS experiment at LHC POS-20 Stephan Winkler Recent Advances in Accelerator Mass Spectrometry of the actinides at the Vienna Environmental Research Accelerator 138

141 Wednesday, 19 th September :45-20:00 FKP & NESY Poster-ID Presenter Title POS-21 Johanna Akbarzadeh The Impact of Temperature and Electric Fields on Surfactant-Molecules - an in-situ SAXS Study POS-22 Tanja Etzelstorfer X-ray strain microscopy on Ge microbridges POS-23 Petra Granitzer Magnetic study of iron oxide nanoparticles dispersed within porous silicon POS-24 Nina Hrauda High Resolution X-Ray Diffraction Studies on Arrays of SiGe Islands POS-25 Stefan Kirnstötter Proton implanted silicon wafers investigated by electron beam induced current measurements POS-26 Martin Leitner Towards kinetic Monte-Carlo simulations with ab initio accuracy POS-27 Roland Johann Morak Wood templated inorganic nanoporous materials: Formation and water adsorption studied by in situ SAXS experiments POS-28 Maurizio Musso Polarisation-dependent Raman characterization of stibnite (Sb 2 S 3 ) POS-29 Josef Oswald Numerical simulations of scanning gate experiments in the quantum Hall effect regime POS-30 Silvia Pabisch The nanomechanics of feather keratin studied by small-angle X-ray scattering 139

142 Wednesday, 19 th September :45-20:00 FKP & NESY (continued) Poster-ID Presenter Title POS-31 Manuel Pacheco Fabrication and optical characterization of CdSe quantum dots POS-32 Peter Parz Defects in an iron-nickel meteorite examined with positrons POS-33 Harald Rennhofer Negative thermal expansion of carbon crystallites measured in single carbon fibres POS-34 Mathias Sassermann Toward polarisation entangled photon pairs from microcavity exciton polaritons Elektromagnetische Levitation POS-35 Alexander Schmon Berührungsfreie Untersuchung von flüssigem Metall an der TU Graz POS-36 Paolo Sereni Polarization-dependent Raman characterization of Stibnite (Sb 2 S 3 ) in the temperature-range 290K-77K POS-37 Manuel Vieider Modeling disorder in self-assembled monolayers with embedded dipoles Wednesday, 19 th September :45-20:00 GEP Poster-ID Presenter Title POS-38 Martin Leitner Alfred Wegener: Second Expedition to Greenland - A photographic window to the past 140

143 Wednesday, 19 th September :45-20:00 LHS (PUS) Poster-ID Presenter Title POS-39 Hans Eck Kinder reisen durch die Wissenschaft POS-40 Erich Reichel Forschendes Lernen als Methode der Kompetenzförderung POS-41 Engelbert Stuetz Mit Magnetfeldern hören POS-42 Stefanie Anna Tritthart Papier erleben POS-43 POS-44 POS-45 POS-46 Wednesday, 19 th September :45-20:00 MBU Ground based MAX-DOAS observations Carlos Armando Alberti of tropospheric trace gases in San Salvador, El Salvador Bioequivalent Solid-State Dosimetry: Michael Hajek Current Trends and Future Developments Review and Cross-comparison of Matroshka Christina Hofstätter Phantom Measurements in Different Compartments of the International Space Station Korrelation relativer Feuchte und Maryam Nikbakhti Stromumwandlungskoeffizient der Dünnschicht-Photovoltaik 5-minute poster-presentation on Thursday, 20 th September 2012, 16:30-17:00 141

144 Wednesday, 19 th September :45-20:00 OGD Poster-ID Presenter Title POS-47 Christian Ganser AFM investigation of kraft pulp fiber swelling in controlled humidity POS-48 Christoph Gleichweit Kinetic Monte Carlo Simulations of Nucleation and Thin Film Growth of Hexaphenyl on Amorphous Mica POS-49 Michael Hohage Susceptibility measurements of Ni nanostructures on Cu(110) POS-50 Markus Kratzer Dynamic plowing lithography and 6P thin film growth on graphene investigated by atomic force microscopy POS-51 Patrice Kreiml Morphological investigations of viscose fibers by atomic force microscopy Growth and structure of WOx POS-52 David Kuhness nanolayers on bare Cu(110) and Cu(110)(2 1)O surfaces POS-53 Albrecht Miletzky Adsorption of Xylan onto Bleached Softwood Fibers POS-54 Monika Mirkowska The contact charging of insulators by atomic force microscopy POS-55 Thomas Obermueller Anisotropic growth of ultrathin Mnoxide nanostructures on Ag(100) POS-56 Jiří Pavelec Surface Chemistry Chamber for analysis of Oxides POS-57 Andreas Pavitschitz Microscopical electrical investigations of grain boundaries in ZnO varistor ceramics 142

145 Wednesday, 19 th September :45-20:00 OGD (continued) Poster-ID Presenter Title POS-58 Alexander Pichler Structure Solution of Surface Induced Crystal Structures: Selected Examples of Calamitic Conjugated Molecules POS-59 Bernhard Putsche Influence of potassium on the nucleation and growth of para-hexaphenyl on mica POS-60 Sebastian Rohm Thin cellulose films as model systems for paper-fibres POS-61 Boris Scherwitzl Initial growth of Rubicene on Silicon Oxide POS-62 Anton Tamtögl Bismuth surface phonon modes from helium atom scattering experiments Attachment limited versus diffusion POS-63 Levent Tümbek limited nucleation of organic molecules: Hexaphenyl on sputtermodified mica POS-64 Thomas Ules Displacement and Replacement in Organic Heterostructures POS-65 Zhiming Wang Reversible transitions between surface reconstructions on SrTiO 3 POS-66 Frederik Weber Investigation of the surface charge of Viscose Fibres by XPS and ATR POS-67 Archim Wolfberger Selective Photo-induced Cross-linking of Polynorbornens: Towards the Fabrication of Polymer 2D- and 3D- Microstructures Wednesday, 19 th September :45-20:00 PMP Poster-ID Presenter Title POS-68 Maurizio Musso Raman investigation of tannin foams POS-69 Soran Nabavi The effect of sacrificial bonds on the mechanical behavior of a single polymer chain- A Monte Carlo study 143

146 Wed, 17:45-20:00 POS-01, AMP, Wed, 17:45 Experimental Investigations of the Hyperfine Structure of 143 Nd + Spectral lines using Collinear Laser Ion Beam Spectroscopy Naveed Anjum 1,2, Nadeem Akhtar 1,2, Harry Hühnermann 1,3, Laurentius Windholz 1 1 Graz University of Technology, Petersgasse 16, 8010 Graz, Austria 2 Optics Labs. P. O. Box 1021, Nilore Islamabad, Pakistan 3 Department of Physics, University of Marburg, Germany We have used the high resolution technique of collinear laser ion beam spectroscopy (CLIBS) for Doppler free investigations of the hyperfine structure (hfs) of spectral lines of singly ionized Neodymium-143 ( 143 Nd + ). Hyperfine structure is caused by the electromagnetic interaction between the nucleus and the electron shell. The study of the hyperfine structure of ions can provide useful information on the nuclear structure and electronic properties of the ions. We used natural Nd in metallic form to produce Nd ions using a surface ion source of Johnson type. Natural Nd is a mixture of five stable and two radioisotopes and the natural abundance of 143 Nd is just 12.2%. The ions are accelerated to 20 kv and then mass separated by an 80 magnet. A collimated ion beam is obtained in the interaction region. In the interaction region the ion velocity is tuned by applying an additional voltage and keeping the laser frequency constant (Doppler tuning). A ring dye laser, pumped by an Argon ion laser, is used as the excitation source and we used dyes Rhodamine 6G and Sulforhodamine B (Kiton Red) to obtain the desired laser wavelengths. Laser induced fluorescence is recorded by using a photomultiplier tube and a photon counter. Magnetic dipole constants A and electric quadrupole constants B of the involved levels have been determined using a fit program. The accuracy of our results is better than that of published values. POS-02, AMP, Wed, 17:45 An ion-photon interface mediated by a cavity Birgit Brandstätter 1 1 University of Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria Quantum networks, in which atoms at quantum nodes are linked by photonic channels, offer a compelling solution to the challenge of scalability in quantum computing. In these networks, optical cavities provide an interface between photons and atoms. We use a trapped calcium ion, which allows for efficient initialization, coherent manipulation, and readout of the quantum state. The ion is coherently coupled to the polarization state of single photon via a high-finesse cavity by driving a vacuum-stimulated Raman transition. We show state mapping of an arbitrary electronic superposition state of the ion to a polarization superposition state of a single photon. In a new experimental setup, we plan to increase the coherent coupling between ion and photon to reach the strong-coupling regime by decreasing the cavity mode volume using fiber Fabry-Perot cavities. 144

147 POS-03, AMP, Wed, 17:45 Omni-directional magnetic field measurement by means of the Coupled Dark State Magnetometer (CDSM) Michaela Ellmeier 1, Roland Lammegger 1, Andreas Pollinger 2, Werner Magnes 2, Laurentius Windholz 1 1 Graz University of Technology, Petersgasse 16, 8010 Graz, Austria 2 Österreichische Akademie der Wissenschaften, Schmiedlstrasse 6, 8042 Graz, Austria The CDSM magnetometer is a new type of optical pumped magnetometer, which measures the scalar value of the magnetic field. The measurement principle is based on the coupling of two dark state resonances established by the coherent population trapping (CPT) effect. The dark state resonances are excited by a circularly polarized, polychromatic laser field consisting of two frequency components 6.8 GHz apart from each other. As a consequence, six magnetic field dependent dark states are created within the hyperfine structure of the 87Rb D1 line, which are combined by a multi-stage modulation process to three coupled dark state resonances. The magnitude of the magnetic field is obtained by extracting the appropriate modulation frequency lying in the range of 300 Hz-1 MHz by means of phase sensitive detection techniques. The benefit of this approach is a significant reduction of the (buffer gas induced) temperature shift of the dark resonances. In contrast to other scalar magnetometers, the CDSM can measure magnetic fields independent on their direction (without the so called dead zones). This novelty is achieved by a proper selection of the resonance with maximum amplitude during the permanent operation of the magnetometer. Therefore, exact knowledge about the relative strengths of the dark resonances is necessary. We demonstrate that the optical pumping effect causes an asymmetry between the coupled resonances, resulting in a totally different angular dependence of the dark resonance amplitudes compared to predictions of theoretical models. This behaviour is used with benefits in the CDSM operation dynamics. POS-04, AMP, Wed, 17:45 Influence of sample temperature on the dynamics and emission line intensities of laser-induced plasma Simon Eschlböck-Fuchs 1, Michael Haslinger 1, Andreas Hinterreiter 1, Philipp Kolmhofer 1, Norbert Huber 1, Roman Rössler 2, Johannes Heitz 1, Johannes Pedarnig 1 1 Johannes Kepler University, Altenberger Straße 69, 4040 Linz, Austria 2 Voest Alpine Stahl, Voest-Alpine-Strasse 3, 4031 Linz, Austria We investigate the influence of sample temperature on the dynamics of the laser induced plasma and on the emission intensities in laser-induced breakdown spectroscopy (LIBS). Bulk aluminum, boron doped silicon, and metallurgical slag samples are heated in air up to temperature TS 500 C and are irradiated by Nd:YAG laser pulses (wavelength 1064 nm, pulse duration approx. 7ns). The plasma dynamics is investigated by fast time-resolved photography. LIBS spectra are taken with an Echelle spectrometer in combination with an intensified CCD camera. For all sample materials investigated the temporal evolution of the plume size and of the LIBS intensities varies systematically with TS. The height and width of the plasma plume and the luminosity of the plasma, as measured by fast photography, increase with increasing temperature. For Al and Si the plasma lifetime is extended to 10 µs at TS = 500 C (compared to 4 µs at TS = 20 C). For slag samples the plasma lifetime does not significantly vary with TS. Increasing emission line intensities are observed for all samples at high temperature. We apply the calibration-free LIBS method to analyze the measured emission spectra and to determine the concentration values for the major oxides in slag at different sample temperature. The LIBS analysis of multi-component samples at high temperature is of interest for technical applications. Acknowledgements: We thank the Austrian Federal Ministry of Economy, Family and Youth and the National Foundation for Research, Technology and Development for financial support. 145

148 POS-05, AMP, Wed, 17:45 Electron driven chemistry close to 0 K Marcelo Goulart 1, Peter Bartl 1, Samuel Zöttl 1, Mathias Daxner 1, David Gschliesser 1, Johannes Postler 1, Carolina Guedes Matias 1, Benjamin Puschnigg 1, Violaine Vizcaino 1, Christian Leidlmair 1, Harald Schöbel 1, Lukas An der Lan 1, Stephan Denifl 1, Andreas Mauracher 1, Michael Probst 1, Olof Echt 2, Andrew Ellis 3, Paul Scheier 1 1 University of Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria 2 University of New Hampshire, DeMeritt Hall 323, 9 Library Way, Durham, New Hampshire, 03824, USA 3 University of Leicester, University Rd, Leicester, LE1 7RH, UK Homogeneous as well as heterogeneous clusters are formed upon pickup of individual atoms and molecules by He nanodroplets. Evaporative cooling of the He matrix leads to an isothermal temperature of 0.37 K. Fragmentation of the dopant cluster during the pickup process is completely quenched by the surrounding He matrix, leading to a neutral cluster size distribution free of any magic numbers. Positive and negative ion formation is studied via electron bombardment of the doped He nanodroplets utilizing mass spectrometry. Intensity anomalies of the cluster size distributions indicate fragmentation processes of the dopant clusters after the ionization process and reflect the stability of the differently sized charged clusters. Electron ionization of He nanodroplets doped with methanol (M) forms predominantly the protonated cations MnH +. Several other abundant cluster ion series can be assigned as (H 2 O)xMnH + with x = 1 5. The intracluster reaction leading to the formation of H 2 O requires a minimum number of methanol molecules, which is n = 5+4x. This work is financially supported by the FWF (P19073, P23657, and L633) POS-06, AMP, Wed, 17:45 Efficient wave function simulations in nonlinear quantum optics using an adaptive coherent state basis Sebastian Krämer 1, Helmut Ritsch 1 1 University of Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria We show that a suitable set of coherent basis states placed on a discrete hexagonal grid can be used to numerically very accurately represent general quantum states in a memory efficient way. Adding an algorithm for dynamic basis adaptation allows highly accurate Quantum Monte Carlo wave function simulations with small basis sets. At the example of the intricate nonlinear dynamics of an optical parametric oscillator around threshold, we demonstrate that this approach yields accurate time dependent solutions with a substantially smaller basis sets than required for a photon number basis. Above threshold the adaptive basis splits into localized subsets allowing efficient representation of bimodal or even more complex phase space distributions and directly yields an intuitive physical picture of the ongoing dynamics. 146

149 POS-07, AMP, Wed, 17:45 In situ ion-trap fabrication apparatus for low ion-heating rates Michael Niedermayr 1 1 University of Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria One promising approach for scalable quantum-information-processing architectures is based on miniaturised surface ion traps. At present, one significant limit to miniaturisation is set by the heating rate of ions, which increases as the ions approach the trap surface. The mechanism of this heating is not yet fully understood, but experimental results indicate that one likely cause is contamination on the surface of the trap electrodes. This is present even after only the briefest exposure to atmosphere. This effect might be mitigated by performing the final trap-fabrication steps in situ, in vacuum. We describe a system to investigate the heating rates of contamination-free gold surface traps. The cryogenic ion-trap chamber is equipped with a thermal evaporation source in vacuum which allows in situ coating of the trap surface with a fresh gold layer. The heating rate will be measured before and after the evaporation. POS-08, AMP, Wed, 17:45 Towards a nuclear clock with Thorium-229 Matthias Schreitl 1, Thorsten Schumm 1, Georgy Kazakov 1, Georg Winkler 1, Georg Steinhauser 1 1 Vienna University of Technology, Stadionallee 2, 1020 Vienna, Austria An improvement of the current time standard could be achieved by exploiting optical transitions with long lifetimes and narrow line widths. Nuclear transitions, which can be more stable against external perturbations, usually have energies in the range of kev or even MeV. Thorium-229 however is predicted to provide a unique excited state only 7.6±0.5 ev [1] above the ground state in the range of UV lasers. An expected lifetime of several hours [1] makes this transition an excellent candidate for a new time standard, with a potential to outperform existing clocks by orders of magnitudes. Our experimental approach consists in embedding Th 4+ in the UV-transparent crystal structure of CaF 2. This provides the advantages of working with a room-temperature solid-state sample with a great number of nuclei. The next steps include the characterization of the crystals doped with Th-232 in order to ensure the transparency in the relevant wavelength region, the reliable substitution of the Thorium ions in the crystal lattice and the role of defects. A broadband UV-lamp will subsequently be used to try to excite the predicted nuclear transition and detect fluorescence in a crystal doped with Th-229. A frequency comb is currently set up which will be transferred to the 160 nm region by a high-harmonic generation build-up cavity and will be used as a precision measurement tool for comparison to other frequency standards. [1] Beck et al., Phys. Rev. Lett. 98, (2007) 147

150 POS-09, FAKT, Wed, 17:45 New Approaches for Improvement of Time-of-Flight PET Stefan Brunner 1, Lukas Gruber 1, Albert Hirtl 2, Johann Marton 1, Martin Jankovec 2, Peter Knoll 3, Ken Suzuki 1 1 Austrian Academy of Sciences, Boltzmanngasse 3, 1090 Vienna, Austria 2 Medical University of Vienna, Währinger Gürtel 18-20, Leitstelle 3L, 1090 Wien, Austria 3 Wilhelminenspital, Montleartsrasse 37, 1160 Wien, Austria Advances in detector technology led to the construction of commercial time of flight (TOF) positron emission tomography (PET) devices, resulting in enhanced image contrast, lower patient s dose and shorter examination times. Commercial TOF-PET scanners with coincidence time resolutions of ps FWHM are already available. Goal of this work is the improvement of time resolution for TOF-PET using Silicon photomultipliers (SiPM) and the Cherenkov effect. Along with many comparable features to ordinary vacuum photomultipliers, SiPMs are considerably smaller in size and insensitive to magnetic fields, which makes them usable for hybrid devices such as PET-NMR. The use of the Cherenkov effect at gamma energies of 511keV should help to improve time resolution of PET detectors dramatically. As Cherenkov photons are emitted almost instantaneously, compared to scintillation photons, the ability to detect and distinguish them from the scintillation signals, provide precise time stamps for TOF. First measurements using PMTs have been accomplished successfully. For the development of a future TOF-PET prototype, Monte Carlo (MC) simulations using the framework GATE and SLitrani are performed to optimise the experimental setup (pixel size, material, arrangement of the SiPMs). The simulated raw data have been analysed by self-developed software and first sinograms have been calculated. In this work the results of recent measurements on the time resolution of our setup, calculations and measurements related to the detection of Cherenkov photons at energies of 511keV, and latest results of MC simulations on new detector designs, will be presented. POS-10, FAKT, Wed, 17:45 qbounce: Ein Frequenzstandard für Gravitationsspektroskopie Gunther Cronenberg 1, Hanno Filter 1, Tobias Jenke 1, Hartmut Abele 1 1 Vienna University of Technology, Stadionallee 2, 1020 Wien, Austria Wir wenden eine Spektroskopiemethode quantisierter Zustände ultrakalter Neutronen im Gravitationspotential an. Diese Methode erlaubt präzise Messungen der quantenmechanischen Übergangsfrequenz eines Schrödinger-Wellenpakets, welches im Schwerefeld der Erde auf einem Neutronenspiegel oszilliert. Den Übergangsfrequenzen entsprechen dabei Energiedifferenzen der Eigenzustände im Picoelektronenvoltbereich, welche nur von der Neutronenmasse, der lokalen Erdbeschleunigung, sowie vom Planckschen Wirkungsquant abhängen. Messungen mit ultrakalten Neutronen erlauben aufgrund ihrer nicht vorhandenen Ladung sowie extrem geringer Polarisierbarkeit eine Sensitivität auf das Newtonsche Gravitationsgesetz oder Abweichungen durch hypothetische, kurzreichweitige Wechselwirkungen ohne den Einfluss elektromagnetischer Störeffekte. Damit können Grenzen auf theoretisch interessante Modelle wie Große Extradimensionen der Raumzeit oder Axionen in dem vergleichsweise wenig untersuchten Mikrometerbereich abgeleitet werden. Eine weitere Ausbaustufe dieser Methode bringt als Vorteil die Selbstfokussierung des Aufbaus, welche eine größere Geschwindigkeitsklasse und damit eine höhere Zählrate der untersuchten Neutronen erlaubt. 148

151 POS-11, FAKT, Wed, 17:45 Momentum Analysis in PERC Jacqueline Erhart 1, Gertrud Konrad 1, Xiangzun Wang 1, Hartmut Abele 1 1 Vienna University of Technology, Stadionallee 2, 1020 Wien, Austria The new user facility Proton and Electron Radiation Channel (PERC) supplies an intense beam of charged decay products arising from the beta decay of free neutrons. This weak interaction process tests the Standard Model and searches for possible extensions. Different detector systems are under development in order to study angular correlations involving the neutron spin, the energies and the momenta of the β-decay products (electrons and protons). Already existing beta decay spectrometers were focused on the measurement of electron and proton energy while PERC permits precise momentum spectroscopy of charged particles for the first time. At the exit of PERC, the electrons and protons leaves the magnet system with a field strength of 0.5T. Therefore, the magnetic field has to drop down rapidly and guarantee the non-adiabatic motion of the particles at the passage to the momentum spectrometer. The new detection concept has to provide a weak vertical magnetic field to separate the particles due to their momenta and charges. The electrons and protons are detected by position sensitive detectors. In this way, electrons and protons can be measured at the same time. The new concept of analyzing the momentum spectra provides an increased resolution in the low energy scale which is needed for investigating, e.g., the Fierz interference term. POS-12, FAKT, Wed, 17:45 Design of the Magnetic Shielding for PERC Philip Haiden 1, Jacqueline Erhart 1, Harald Fillunger 1, Miklos Horvath 1, Gertrud Konrad 1, Stefan Schwarz 1, Xiangzun Wang 1, Hartmut Abele 1 1 Vienna University of Technology, Stadionallee 2, 1020 Wien, Austria The new facility PERC (Proton Electron Radiation Channel) is a novel source of neutron decay products. PERC is currently under development by an international collaboration and will be installed at the FRM II in Garching, Germany. The main component of PERC is a more than 11 m long superconducting magnet system, with a strong longitudinal magnetic field of 0.5 T up to 6 T. In order not to disturb other experiments in the vicinity of PERC, we have designed a magnetic field return yoke for the magnet system. The following aspects must be taken into consideration: the magnetic stray field must be suppressed to the cardiac pacemaker level, the internal magnetic field and its homogeneity should not be disturbed, the additional forces onto the coils must not be destructive, and the magnetic shielding must deal with the limited space conditions. We will show that for experimental reasons, the magnet geometry is non-axisymmetric and therefore has to be simulated in three dimensions. In order to reduce the computing time and, at the same time, increase the numerical accuracy, we simulated only one half of the geometry by taking advantage of the symmetry of the magnet and its shielding. The design of the magnetic shielding for PERC will be presented in this poster: The finite element method (COMSOL Multiphysics) has been used to determine the most suited geometry for the magnetic shielding. Various geometries and combinations of shielding materials of non-linear permeability have been simulated. 149

152 POS-13, FAKT, Wed, 17:45 Strangeness Production in p p Collisions at FOPI Katharina Isepp 1 1 Austrian Academy of Sciences, Boltzmanngasse 3, 1090 Vienna, Austria According to theoretical predictions [1] deeply bound kaonic states are possibly created in proton-proton collisions. To verify them experimentally the FOPI detector at GSI [2] investigated a 3.1 GeV proton beam targeting on liquid hydrogen in In this reaction the Λ(1405) resonance plays a special role. It can be interpreted as a pk bound state which serves as a doorway state to produce the deeply bound state ppk. This state decays eventually with a large branching ratio into a Λ hyperon and a proton. The poster presents the reconstruction of the Λ involved in the p + p pk + Λ final state from its decay products π and p. [1] Y. Akaishi and T. Yamasaki, PRC 76, , 2007 [2] / www-fopi.gsi.de POS-14, FAKT, Wed, 17:45 Proton Spectroscopy with PERC Michael Klopf 1, Jacqueline Erhart 1, Gertrud Konrad 1, Hartmut Abele 1 1 Vienna University of Technology, Stadionallee 2, 1020 Wien, Austria The PERC collaboration will perform high-precision measurements of angular correlations in neutron beta decay at the FRM II in Garching, Germany. The new facility PERC, a novel source of neutron decay products, is designed to improve the sensitivity of neutron decay studies by one order of magnitude. Depending on the angular correlations studied with PERC, the analysis of the extracted decay electrons and protons is performed with different and specialized detectors. As far as protons are concerned, PERC will feed a charged particle spectrometer, for instance an adapted spectrometer which can partially be based on the aspect detection system. The analysis of the decay protons is based on a precise energy measurement, by means of an electrostatic filter or by time-of-flight measurement. Then, e.g., the electric potential between the decay and filter regions (0 780 V) has to be known with an accuracy of better than 10 mv. Up to the completion of the PERC instrument, systematic uncertainties in the analysis of decay protons are investigated with the aspect spectrometer. In order to, e.g., avoid electrical breakdowns initiated by and discharges due to field emission from the high voltage electrodes, the high voltage system has been redesigned. Besides the physics motivation, the optimization of the aspect spectrometer, the detection concept and the dominant systematic uncertainties for PERC will be presented in this poster. 150

153 POS-15, FAKT, Wed, 17:45 Local-Duality QCD Sum Rules for Pseudoscalar-Meson Form Factors Wolfgang Lucha 1, Irina Balakireva 2, Dimitri Melikhov 1 1 Österreichische Akademie der Wissenschaften, Nikolsdorfer Gasse 18, 1050 Wien, Austria 2 Moscow State University, SINP, , Moscow, Russia Utilizing the local-duality formulation of QCD sum rules, we scrutinize anew some strange findings for the charged-pion elastic form factor and for the form factor describing the neutral-pion transition to one real and one virtual photon within a broad range of momentum transfers. The uncertainties of the local-duality approximation to the QCD sum-rule formalism are estimated by analyzing, in parallel to QCD, quantum-mechanical potential models, where the exact form factors may be easily obtained by solving the Schrödinger equation and then compared with the localduality sum-rule outcomes. From these studies, we expect the accuracy of the predictions of simple local-duality models to improve very fast with increasing momentum transfer and thus regard large deviations from the elastic pion form factor s local-duality behaviour, recently predicted by some hadron-structure models, as rather unlikely. Furthermore, in startling contrast to the excellent agreement of the local-duality results for the (η, η, η c) γ + γ transition form factors, recent BABAR measurements of the π γ + γ transition form factor imply inexplicable local-duality violations which even rise with momentum transfer. POS-16, FAKT, Wed, 17:45 Investigations of negative ion formation in Middleton type ion sources Martin Martschini 1, Pontus Andersson 1, Oliver Forstner 1, Robin Golser 1, Dag Hanstorp 2, Anton Lindahl 2, Johan Rohlén 2 1 University of Vienna, Währinger Strasse 17, 1090 Wien, Austria 2 University Gothenburg, Fysikgränd 3, Plan 8 rum F8032, SE Göteborg, Sweden Since 1977, sputter ion sources of the Middleton type have been the main tool used to create stable, intense negative ion beams for Accelerator Mass Spectrometry (AMS). Nevertheless, the theory behind negative ion formation is not fully agreed upon and recipes for high current output differ from lab to lab. A better understanding of the sputtering process is expected to allow further optimization of negative ion sources and thereby enhance the abundance sensitivity of AMS for several radioisotopes. As part of the work in trying to unravel the mechanisms of hard sputtering in a cesium rich environment, we have resolved the spectrum of blue light emitted from the cathode region during high current output. A fiber coupled spectrometer was used to detect light in the wavelength region 200 to 1100 nm. When sputtering a carbon target, the emitted light consists almost entirely of persistent lines from neutral cesium. To our surprise, the spectra from aluminum or copper targets showed also persistent lines from Cs +. In another experiment, the effect of continuous wave laser light directed onto the cathode surface was studied. Independent from wavelength, the laser light induced a significant change in oxygen, sulfur and chlorine negative ion production from a AgCl target. Approximately 100 mw of laser light changed the elemental composition of the ion beam by one order of magnitude. This technique was successfully applied during a regular AMS measurement of 36Cl at VERA (Vienna Environmental Research Accelerator). The physics behind the effect still requires further investigations. 151

154 POS-17, FAKT, Wed, 17:45 Elektronen-Energie-Detektion für PERC Martin Moser 1, Thomas Cervinka 1, Jacqueline Erhart 1, Gertrud Konrad 1, Sebastian Maaß 1, Xiangzun Wang 1, Hartmut Abele 1 1 Vienna University of Technology, Stadionallee 2, 1020 Wien, Austria Das freie Neutron zerfällt auf Grund der schwachen Wechselwirkung über den Betazerfall in ein Proton, ein Elektron und ein Elektron-Antineutrino. Über die Winkelkorrelationen dieser Teilchen ist es möglich, die Gültigkeit des Standardmodells der Teilchenphysik zu überprüfen bzw. zu erweitern. Das neue Instrument PERC ermöglicht es, die Korrelationskoeffizienten zwischen dem Neutronenspin und den Impulsen der Zerfallsprodukte in noch nie dagewesener Präzision zu messen; da die Zerfallsrate bei 10 6 liegen wird. Das zum Einsatz kommende Elektronenspektrometer basiert auf dem von unserer Arbeitsgruppe an der Universität Heidelberg entwickelten und vom Atominstitut der Technischen Universität Wien, zur Erhöhung der Effizienz, adaptierte Spektrometer PERKEO3. In Wien wird einer der Detektoren von PERKEO3 charakterisiert und dessen für die Elektronenspektroskopie relevanten Systematiken untersucht. Das Ziel ist Elektronenspektroskopie auf 10 4 Niveau. Die Energiedetektion erfolgt dabei über Szintillatoren mit Photomultiplierauslese, auf denen besonderes Augenmerk liegt: Auf Grund ihrer kurzen Auslesezeit und hohen Zeitauflösung ist es möglich, bei besonders hohen Zählraten zu arbeiten, was gerade für PERC von großer Bedeutung ist. Zusätzlich wird auch die Stabilität des Messsystems erhöht und charakterisiert, um eine mögliche Variation von Zerfallskonstanten zu bestimmen. Ergänzend zu den direkten Stabilitätstests mit Eichproben werden auch Monte Carlo Berechnungen durchgeführt, die sowohl das Rückstreuverhalten sowie die Elektronenabsorption und -transmission aus dem Szintillationsmaterial als auch dem Detektorgehäuse aus Edelstahl untersuchen. Diese Simulationen werden mittels der speziell dafür entwickelten Simulationssoftware CASINO durchgeführt. POS-18, FAKT, Wed, 17:45 A new very-large Perfect Crystal Neutron Interferometer Thomas Potocar 1, Ulrich Kuetgens 2, Michael Zawisky 1, Harald Huber 1 1 Vienna University of Technology, Stadionallee 2, 1020 Wien, Austria 2 Physikalisch-Technische Bundesanstalt, Bundesallee 100, Braunschweig, Germany The different stages of the machining of the largest crystal interferometer are presented. Path length, beam separation and enclosed beam area are exceeding, by far, the dimensions of hitherto prepared interferometer crystals. Due to its large dimensions and the steplike cut middle plates it can be used as multi-purpose instrument: The interferometers lower part serves as a compact, extremely sensitive angle measuring device. The upper part is mainly used for gravitation experiments where three interference loops can be used with the same interferometer. This research was funded by the Austrian Science Fund (FWF): Project I530-N

155 POS-19, FAKT, Wed, 17:45 Global Trigger Upgrade project for the CMS experiment at LHC Babak Rahbaran 1 1 Österreichische Akademie der Wissenschaften, Nikolsdorfer Gasse 18, 1050 Wien, Austria The electronics of the first Level Global Trigger (GT) of CMS is the last stage of the Level-1 trigger system. At LHC up to 40 million collisions of proton bunches occur every second, resulting in about 800 million proton collisions. The CMS Level-1 Global Trigger, a custom designed electronics system based on FPGA technology and the VMEbus system, performs a quick on-line analysis of each collision every 25 ns and decides whether to reject or to accept it for further analysis. Various parts of the CMS trigger and in particular the Level-1 hardware trigger will be upgraded to cope with increasing luminosity, using more selective trigger conditions at Level-1 and improving the reliability of the system. The CMS trigger group of the Institute of High Energy Physics in Vienna (HEPHY) is involved in the Level-1 trigger of the CMS experiment at CERN. As part of the Trigger Upgrade, the Level-1 Global Trigger will be redesigned and implemented in MicroTCA based technology, which allows engineers to detect all possible faults on plug-in boards, in the power supply and in the cooling system. The upgraded Global Trigger will be designed to have the same basic categories of functions as the present GT, but will have more algorithms and more possibilities for combining trigger candidates. Additionally, reconfigurability and testability will be supported based on the next system generation. POS-20, FAKT, Wed, 17:45 Recent Advances in Accelerator Mass Spectrometry of the actinides at the Vienna Environmental Research Accelerator Stephan Winkler 1, Peter Steier 1, Alfred Priller 1, Josef Buchriegler 1, Robin Golser 1 1 University of Vienna, Währinger Strasse 17, 1090 Wien, Austria Actinides have wide application in environmental science, both as tracer and as dating tool. Accelerator Mass Spectrometry (AMS) has been shown to allow for the lowest isotope ratio detection limits for actinides. However, careful design of the spectrometer and an understanding of beam and atomic physics is required to achieve the detection limits required for the measurement of naturally occurring 236-U or the artificially produced plutonium isotopes beyond mass 240 in the general environment. We present our latest developments and improvements at the Vienna Environmental Research accelerators heavy isotope beam-line and give also a wider perspective on the design of an ideal heavy-ion AMS system. 153

156 POS-21, FKP & NESY, Wed, 17:45 The Impact of Temperature and Electric Fields on Surfactant-Molecules - an in-situ SAXS Study Johanna Akbarzadeh 1, Sylvia Flaig 2, Nicola Huesing 2, Herwig Peterlik 1 1 University of Vienna, Strudlhofgasse 4, 1090 Vienna, Austria 2 Paris-Lodron University Salzburg, Hellbrunner Strasse 34, 5020 Salzburg, Austria The combination of different synthetic strategies such as sol-gel processing together with templating approaches have been proven to be an effective method in the preparation of long range ordered mesoporous materials. However, for many applications (e.g. microelectronic devices, membranes...) not only highly ordered mesopores but also a precisely defined pore orientation would be desirable. One way to achieve such highly oriented mesopores is the exposure of the sample to an electric field during the sol-gel process. Electric field induced orientation of mesopores has already been reported in literature, for example Ku et al. have shown that the application of an low-strength electric field in the preparation of surfactant - templated nanoscopic silica fibers leads to oriented nanochannels with both micrometer and nanometer levels of hierarchy. Trau et al. have demonstrated that the use of high-strength electric fields in the production of nanoscopic patterned thin films leads to nanochannels oriented parallel to the applied electric field. In this work we investigate the temperature dependence of different (anionic, cationic and zwitterionic) surfactant molecules in an external electric field ranging from some kv/m up to 1 MV/m. These molecules will further serve as a template phase in the sol-gel process to produce long range ordered and highly oriented mesoporous materials. The structural change on the nanometer level is followed in-situ by small-angle X-ray scattering. POS-22, FKP & NESY, Wed, 17:45 X-ray strain microscopy on Ge micro-bridges Tanja Etzelstorfer 1, Martin Süess 2, Gustav Schiefler 3, Ana Diaz 3, Hans-Christian Sigg 3, Vincent Jaques 4, Daniel Chrastina 5, Giovanni Isella 5, Ralph Spolenak 2, Julian Stangl 1 1 Johannes Kepler University, Altenbergerstrasse 69, 4040 Linz, Austria 2 ETH Zürich, Wolfgang-Pauli-Strasse 16, 8093 Zurich, Switzerland 3 Paul Scherrer Institut Paul Scherrer Institut, 5232 Villigen PSI, Switzerland 4 ESRF, 6 Rue Jules Horowitz, BP 220, Grenoble Cedex 9, France 5 Politecnico di Milano, Piazza L. da Vinci, 32, Milano, Italy In the SiGe system optical emitters are difficult to realize due to the indirect band gap. Employment of tensile strain in Ge is a promising route to shift to the indirect transition. Technical realization of required strain values of a few per cent is, however, rather difficult and requires complex strain microscopy. In this study micro bridges are investigated, where strain enhancement in about 0.2 % tensile pre-strained Ge layers grown on Si is achieved. The transfer of an electronbeam written pattern leads to force field concentration. By tuning the geometry of the structure, the strain may be enhanced to levels high enough to convert the indirect band gap to a direct one. The strain distribution in tensile strained Ge micro-bridges is studied by X-ray nano-diffraction, which is an excellent tool to spatially resolve the 3D displacement field. The strain mapping of the transition regions between the centre of the bridge and the wide feeder arms was performed at beamline ID01 of the ESRF. Single bridges were raster-scanned in real space, while Ge Bragg peaks were recorded in 3D. This allows to map Bragg peaks with a resolution close to the beamsize and thereof to quantify the strain in the bridges with a spatial resolution of around 300 nm. These results, together with finite-element calculations, will be used to understand strain limitations of Ge and hence its lasing potential, establishing an important milestone in the development of Si-CMOS compatible laser sources. 154

157 POS-23, FKP & NESY, Wed, 17:45 Magnetic study of iron oxide nanoparticles dispersed within porous silicon Petra Granitzer 1, Klemens Rumpf 1, Puerto Morales 2, Peter Pölt 3, Michael Reissner 4 1 University of Graz, Universitätsplatz 5, 8010 Graz, Austria 2 CSIC Madrid, Serrano, Madrid, Spain 3 Graz University of Technology, Steyrergasse 17, 8010 Graz, Austria 4 Vienna University of Technology, Wiedner Hauptstraße 8-10, 1040 Wien, Austria Iron oxide nanoparticles (NPs) of 3.8, 5 and 8 nm have been infiltrated into the pores of porous silicon. The aim is to create a superparamagnetic (SPM) nanocomposite system with maximized magnetic moment. Therefore the particle size versus the superparamagnetic behaviour has been figured out. The blocking temperature TB which indicates the transition between SPM behaviour and blocked state is not only dependent on the particle size but also the magnetic interactions between them which can be varied by the distance between the particles. Thus a modification, on the one hand of the pore-loading and on the other hand of the porous silicon morphoplogy results in a composite material with a desired TB. Because both materials, the mesoporous silicon matrices as well as the Fe 3 O 4 -NPs offer low toxicity the system is a promising candidate for biomedical applications as e.g. magnetic field guided drug delivery. POS-24, FKP & NESY, Wed, 17:45 High Resolution X-Ray Diffraction Studies on Arrays of SiGe Islands Nina Hrauda 1, Jianjun Zhang 2, Heiko Groiss 1, Tanja Etzelstorfer 1, Vaclav Holy 3, Julian Stangl 1, Günther Bauer 1 1 Johannes Kepler University, Altenbergerstrasse 69, 4040 Linz, Austria 2 IFW Dresden, Helmholtzstrasse 20, Dresden, Germany 3 Charles University Prague, Ke Karlovu 5, Praha, 12116, Czech Republic The Si-Ge material system is an interesting topic for both for basic research advanced nanoscale devices as well. To speed up silicon-based transistors both tensile (for n-type) or compressive strain (for p-type) can be applied to the Si-channel of MOSFETs, depending on the setup. Several approaches exist to induce that strain like the application of stressed nitride layers or the use of planar SiGe stressor structures. Our research focuses on the use of epitaxially grown 3D SiGe islands that occur due to the lattice mismatch of 4.2% between Si and Ge. We present studies based on X-ray diffraction and finite element method modeling including both dome- and barn-shaped SiGe islands grown on prepatterned Si(001) substrates. The overgrowth of highly relaxed SiGe islands with Si results in tensile strain in the Si layer above the buried island. The amount of strain depends on several factors such as the composition of the buried island, its shape, as well as the thickness of the capping layer. Growing SiGe islands in a closely-spaced configuration can be used to induce compressive strain in the sections of the Si cap layer situated between those islands. 155

158 POS-25, FKP & NESY, Wed, 17:45 Proton implanted silicon wafers investigated by electron beam induced current measurements Stefan Kirnstötter 1, Peter Hadley 1, Werner Schustereder 2, Martin Faccinelli 1 1 Graz University of Technology, Petersgasse 16, 8010 Graz, Austria 2 Infineon Technologies Austria AG, 9500 Villach, Austria Electron Beam Induced Current (EBIC) is an analysis method used in a Scanning Electron Microscope (SEM) to investigate buried junctions or defects in semiconductors. During an EBIC measurement, the electron beam enters a semiconductor and generates electron-hole pairs. If the charge carriers diffuse into a region where there is a built-in electric field, such as a pn junction or a Schottky contact, charge separation will occur and a current will flow. This is similar to what happens in a solar cell except in an EBIC measurement the electron-hole pairs are generated by the electron beam instead of by light. We have used EBIC to investigate proton implanted silicon wafers with implantation doses from p + /cm 2 to p + /cm 2 and with implantation energies from 500 kev to 5 MeV. The implantation introduces vacancies, silicon interstitials, and hydrogen into the crystal. The sample is then annealed in the temperature range from room temperature to 1000 C and defect complexes form. The microscopic structure of these defect complexes is not completely understood. There is a class of oxygen-vacancy defect complexes called thermal donors that are known to act as donors in silicon. Since electron-hole pairs recombine at defects, the EBIC signal is decreased if the charge carriers have to diffuse past defects on their way to the measurement contacts. POS-26, FKP & NESY, Wed, 17:45 Towards kinetic Monte-Carlo simulations with ab initio accuracy Martin Leitner 1, Tobias Kerscher 1, Stefan Müller 2, Raimund Podloucky 1 1 University of Vienny, Sensengasse 8/7, 1090 Vienna, Austria 2 Hamburg University of Technology, Denickestrasse 15 (K), Hamburg, Germany For the Ni Pt and Fe Cu alloy system we present the first steps towards kinetic Monte-Carlo (KMC) simulations with ab initio accuracy. Many body interactions which describe the energetics of both the local minima and migration states are included by cluster expansions (CE) in the framework of the UNCLE code [1]. In this model approach single atoms jump to vacant nearest-neighbor sites and have to overcome configuration dependent migration barriers. According to transition state theory (TST) jump rates are then derived by the energy difference between initial and saddle point state. The KMC simulations require a) vacant lattice sites, which enforce a ternary CE for a binary compound, and b) the configuration dependent height of the saddle points, which have to be calculated and included in the CE. We discuss different aspects of jump profiles in the respective systems computed by density functional theory (DFT) calculations. The support of FWF project 4110 (ViCoM) is acknowledged. [1] D. Lerch et al., Modelling Simul. Mater. Sci. Eng. 17 (2009),

159 POS-27, FKP & NESY, Wed, 17:45 Wood templated inorganic nanoporous materials: Formation and water adsorption studied by in situ SAXS experiments Roland Johann Morak 1, Gerhard Fritz-Popovski 1, Daniel Van Opdenbosch 2, Cordt Zollfrank 2, Barbara Aichmayer 3, Oskar Paris 1 1 Montanuniversität Leoben, Franz-Josef Strasse 18, 8700 Leoben, Austria 2 Technische Universität München, Schulgasse 16, Straubing, Germany 3 MPI of Colloids and Interfaces, Wissenschaftspark Potsdam-Golm, Potsdam, Germany Wood is an abundantly occurring hierarchically structured composite material. It consists of fibrils of diameter nm, which are embedded into a lignin matrix. These fibrils consists themselves of cellulose microfibrils of diameter 2-3 nm embedded in surrounding hemicelluloses. In this work, wood was used as a template in order to obtain inorganic materials with chiral nanopores. The necessary preparation steps are deliginification, cell-wall modification with maleic acid anhydride, infiltration with tetraethyl orthosilicate (TEOS) and calcination. We studied the transformation of the composite material to porous silica using synchrotron radiation for in-situ SAXS experiments during the calcination of the sample. The nano-structure changed progressively from fibrils with a nearly homogeneous electron density and with a diameter of nm to fibrils with diameters of 8-10 nm. Modeling of the results revealed a two step process. The hemicelluloses disintegrate at C and amorphous silica is formed. The cellulose fibrils, which are embedded in amorphous silica after this step, are still intact. At C the cellulose degrades and leaves nanometer sized pores within the silica. The gas adsorption properties of these materials were studied further by in-situ adsorption experiments with SAXS and compared to results obtained from gravimetric measurements. The gravimetric measurements feature the existence of accessible pores whereas the scattering parameters imply a change of the material structure during a sorption cycle. POS-28, FKP & NESY, Wed, 17:45 Polarisation-dependent Raman characterization of stibnite (Sb 2 S 3 ) Maurizio Musso 1, Paolo Sereni 1, Kurt Krenn 2, Peter Knoll 1, Peter Blaha 3, Karlheinz Schwarz 3, Günther Schmidt 3 1 University of Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg, Austria 2 University of Graz, Universitätsplatz 2, 8010 Graz, Austria 3 Vienna University of Technology, Getreidemarkt 9/165-TC, 1060 Vienna, Austria Single crystal samples of Stibnite (Sb 2 S 3 ), a naturally occurring sulfide mineral with semiconducting properties (band gap 1.72 ev), were studied by polarization-dependent Raman spectroscopic measurements using both visible and NIR laser excitation. In the case of visible laser excitation at 532 nm (2.33 ev) the laser light was highly absorbed, being the photon energy higher than the band gap of the semiconductor; measurements at 180 scattering geometry (backward scattering) were therefore only possible. In the case of NIR laser excitation at 1064 nm (1.17eV) the photon energy was lower than the band gap of the semiconductor, the sample therefore resulting transparent to the excitation line, therefore allowing polarization-dependent measurements both in 180 and 90 scattering geometry. The analysis of the group symmetries yields 10 Ag, 5 B1g, 10 B2g, and 5 B3g Raman active vibrational modes. The comparison of the corresponding Raman frequencies calculated using the ab-initio WIEN2k and PHONON codes [1] with our experimental values obtained both in 90 and in 180 scattering geometries shows overall good qualitative agreement, although the discrimination between Ag and B2g modes, and that between B1g and B3g modes in the experimental spectra is still challenging, since the number of bands is the same for both modes, and the calculated band positions quite close. [1] P. Blaha, K. Schwarz, G.K.H. Madsen, D. Kvasnicka, J. Luitz, WIEN2k (2001) ; K.Parlinski, Software PHONON, Cracow (2002). 157

160 POS-29, FKP & NESY, Wed, 17:45 Numerical simulations of scanning gate experiments in the quantum Hall effect regime Josef Oswald 1 1 Montanuniversität Leoben, Franz-Josef-Strasse 18, 8700 Leoben, Austria In combination with the scanning gate microscope (SGM), the quantum Hall (QH) system provides a possibility for studying transport in coherent electronic systems. A gate tip introduces a local distortion and the response of the device is recorded versus tip position. We use a nonequilibrium network model (NNM) for transport and combine it with a full quantum mechanical many particle calculation of the disordered electron system on the Hartree-Fock level. The disordered potential of the electronic system can be understood as a native random arrangement of quantum dots and quantum point contacts, which interact in a complex way. Either caused by a sweeping magnetic field or by moving a biased gate tip, any changes of the quantum states are sensitively monitored also by the Hartree part of the self-consistent Hartree-Fock solution, which modulates the transmission behaviour of the involved saddle potentials. That is sensitively detected by our network model and results e.g. in resistance fluctuations. We present preliminary simulation results for both, magneto resistance fluctuations and responsivity maps for a moving gate tip. The importance of the electron-electron interaction in our simulations is demonstrated by turning on and off the Hartree part of the Hatree-Fock solution for the screened random potential. Financial Support: Austrian Science Foundation FWF Project.Nr. P19353-N16 POS-30, FKP & NESY, Wed, 17:45 The nanomechanics of feather keratin studied by small-angle X-ray scattering Silvia Pabisch 1, Ingrid Weiss 2, Helmut Kirchner 2, Stephan Puchegger 1, Herwig Peterlik 1 1 University of Vienna, Strudlhofgasse 4, 1090 Vienna, Austria 2 INM Leibniz-Institut für Neue Materialien ggmbh, Campus D2 2, Saarbrücken, Germany Feather keratin is a highly conserved protein of 98 amino acids synthesized intracellularly in aves. In the cortex of the tail covert feathers of the peacock it forms a crystalline structure, held together by disulfide bonds between the nine cysteines of the molecule. Despite the biological importance of the molecule, its spatial structure has not yet been determined. Fraser and Parry proposed a crystallographic arrangement of beta-barrels and relegate the N-terminus and the C- terminus to an amorphous matrix, akin to the situation in silk [1]. Therefore, in-situ tension and compression tests were made to investigate the changes in axial and lateral direction. Nanoscopically a pronounced structural asymmetry between tension and compression rules out a dihedral axis normal to the fibril direction, and indicates a strong clip-like polarization of the molecule. Based on these X-ray diffraction data from Pavo cristatus feathers, a model is presented for the axial and lateral arrangement of the molecule in feather keratin, which integrates biochemical structure and mechanical experiments. [1] R. D. B. Fraser, D. A. D. Parry, J. Struct. Biol. 162 (2008)

161 POS-31, FKP & NESY, Wed, 17:45 Fabrication and optical characterization of CdSe quantum dots Manuel Pacheco 1, Carlos Rudamas 1 1 Universidad de El Salvador, Escuela de Física, 25 San Salvador, El Salvador In this paper we present results of the optical characterization of CdSe quantum dots (QDs) fabricated using the thermal decomposition technique. For the preparation of the samples we used two precursor solutions to generate the reaction which was initiated at a temperature of 225 C. Ten aliquots were collected at different time intervals during the synthesis. The optical properties of these samples have been studied by absorption spectroscopy and photoluminescence spectroscopy. The maximum of the absorption bands show a shift to lower energies from 2.95 ev to 2.35 ev as the size of the quantum dots increase. Photoluminescence bands also exhibit a similar shift from 2.66 ev to 2.17 ev. Stokes-Shifts from 20 nm to 40 nm were estimated. The full width at half maximum (FWHM) obtained for the photoluminescence bands ranges from 30 nm to 45 nm, which indicates a very good mono-dispersivity of the samples. To calculate the size of the quantum dots we used the effective mass approximation and the absorption spectra for each sample. Quantum dot radii obtained by using this model vary from 1.73 nm to 2.49 nm. POS-32, FKP & NESY, Wed, 17:45 Defects in an iron-nickel meteorite examined with positrons Peter Parz 1, Matthias Leitner 1, Wolfgang Sprengel 1, Werner Puff 1 1 Graz University of Technology, Petersgasse 16, 8010 Graz, Austria A typical iron-nickel meteorite (Gibeon) with a composition of Ni 7,93 wt-%, Co 0.41 wt-%, P 0.04 wt-%, 91.62wt-% Fe and small amounts of carbon, was investigated by positron annihilation methods (positron lifetime spectroscopy and coincidence Doppler broadening). This meteorite exhibits the typical Widmanstätten structure, a two-phase microstructure of Fe-rich Kamacite and Ni-rich Taenite, which is formed due to unique cooling rates of about approximately 35K per one million years. Upon the low cooling rates in space and the formation of the Widmanstätten structure, the meteorite sample was expected to be in equilibrium condition and free of defects. However, a high mean positron lifetime was observed, which derives from open volume defects. The meteorite samples were then gradually heated in a high-vacuum furnace, cooled down to room temperature and probed. The temperature treatment leads to a decrease of the mean positron lifetime, as well as a gradual evolution of the 2d-DB spectra towards pure iron. This results lead to the conclusion, that in the progress of the formation of the Widmanstätten structure open volume defects are introduced. Upon heat treatment these defects start to dissolve and do not re-appear. We attribute these open volume defects to misfit dislocations between the Kamacite (Ni-poor) and Taenite (Ni-rich) structures. 159

162 POS-33, FKP & NESY, Wed, 17:45 Negative thermal expansion of carbon crystallites measured in single carbon fibres Harald Rennhofer 1, Stephan Puchegger 1, Silvia Pabisch 1, Stefan Siegel 2, Chenghao Li 2, Oskar Paris 3, Herwig Peterlik 1 1 University of Vienna, Strudlhofgasse 4, 1090 Vienna, Austria 2 Max-Planck Institute of Colloids and Interfaces, Potsdam, Germany 3 Montanuniversität Leoben, Franz-Josef Strasse 18, 8700 Leoben, Austria In-situ X-ray scattering experiments on single carbon fibres have been performed at BESSY Berlin. The structural response to simultaneous application of temperature and load was studied by Small- and Wide Angle X-ray Scattering, respectively. In this work the thermal expansion of the crystallites in the carbon fibres (MPP and PAN) is presented. At temperatures below 800 C negative thermal expansion in the graphite planes was measured for the MPP fibres. The relationship with the macroscopic thermal expansion is given by the misalignment of the crystallites with respect to the fibre axis i.e. the degree of graphitization. POS-34, FKP & NESY, Wed, 17:45 Toward polarisation entangled photon pairs from microcavity exciton polaritons Mathias Sassermann 1, Lukas Einkemmer 1, Patrick Mai 1, Zoltán Vörös 1, Gregor Weihs 1, Tobias Zederbauer 2, Hermann Detz 2, Aaron Maxwell Andrews 2, Gottfried Strasser 2, Christian Schneider 3, Andreas Löffler 3, Sven Höfling 3, Alfred Forchel 3, Stefano Portolan 4 1 University of Innsbruck, Technikerstrasse 13, 6020 Innsbruck, Austria 2 Vienna University of Technology, Karlsplatz 13, 1040 Vienna, Austria 3 Universität Würzburg, Am Hubland, Würzburg, Germany 4 Institut Néel-CNRS, 25 avenue des Martyrs, BP Grenoble, Cedex 9, France The strong coupling of photons and quantum well excitons in semiconductor microcavities leads to the formation of new quasi particles called polaritons. Due to their peculiar dispersion curve and the convenient experimental accessibility microcavity polaritons have gained considerable interest in the recent years. Polariton states can be selectively populated by choosing the excitation angle and the wavelength of the excitation laser. After a lifetime of a few picoseconds the polariton decays and a photon is emitted from the cavity. This photon carries the whole information on the previous polariton state.so far the focus in this field was mainly on polariton lasing, BEC, non-classical correlations and collective phenomena in semiconductors. Recent theoretical studies suggested utilizing polariton-polariton scattering for generation of entangled photon pairs. S.Portolan et al.(epl (2009)) have proposed a scheme based on polariton four-wave mixing in order to generate polarisation entangled photon pairs. The experimental implementation of this scheme requires two pump beams with different incidence angles and wavelengths. For this purpose we employ a multidimensional spectroscopy setup based on two spatial light modulators (Appl. Phys Lett (2012)). As a first step towards polariton entanglement parametric polariton scattering under two-colour excitation has to be established. In this contribution we will show first results on such scattering experiments and will demonstrate the feasibility of the proposal in Portolan et al. The experimental results will be compared to detailed numerical simulations based on a Langevin master equation approach. 160

163 POS-35, FKP & NESY, Wed, 17:45 Elektromagnetische Levitation Berührungsfreie Untersuchung von flüssigem Metall an der TU Graz Alexander Schmon 1, Kirmanj Aziz 1, Gernot Pottlacher 1 1 Graz University of Technology, Petersgasse 16, 8010 Graz, Austria Flüssiges Metall als Untersuchungsobjekt stellt besonders hohe Ansprüche an den experimentellen Messaufbau um dem Prinzip der Interaktionsreduktion als Messvoraussetzung gerecht zu werden. Die Methode der Elektromagnetischen Levitation ermöglicht eine tiegelfreie Bestimmung von thermophysikalischen Eigenschaften metallischer Schmelzen. Derzeit wird der Aufbau einer entsprechenden Apparatur am Institut für Experimentalphysik der TU Graz fertiggestellt. Dabei werden durch ein inhomogenes elektromagnetisches Hochfrequenzfeld Wirbelströme im Probenmaterial erzeugt, welche aufgrund der ausgeübten Lorentzkraft ein frei schwebendes Positionieren der Probe ermöglichen und gleichzeitig zu einem Aufheizen des Probenmaterials bis in die flüssige Phase führen. Die Probentemperatur wird optisch durch pyrometrische Messung bestimmt und gleichzeitig die Probengeometrie mittels zweier High-Speed-Kameras aufgezeichnet. Unter Verwendung dieser Messgrößen wird die Bestimmung von Dichte und Oberflächenspannung der Probe in Abhängigkeit von der Temperatur ermöglicht. Das Projekt Messung von Oberflächenspannung und Dichte mittels Levitation wird vom Fonds zur Förderung der wissenschaftlichen Forschung (FWF) gefördert - Projekt P N20 POS-36, FKP & NESY, Wed, 17:45 Polarization-dependent Raman characterization of Stibnite (Sb 2 S 3 ) in the temperature-range 290K-77K Paolo Sereni 1, Maurizio Musso 1, Stefan Volgger 1, Christoph Oberauer 1, Peter Knoll 2 1 University of Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg, Austria 2 University of Graz, Universitätsplatz 5, 8010 Graz, Austria A complete set of measurements of the polarization-dependent Raman spectra of Stibnite (Sb 2 S 3 ) in the temperature range from 290K to 77K are here presented and compared with those obtained in our previous activities [1]. The used equipment consisted of a 1064 nm polarized laser excitation, an FT-Raman spectrometer (Bruker IFS66 + FRA106) and an Optistat LN 2 Bath Cryostat (Oxford Instruments). [1] P. Sereni et al., AIP Conference Proceedings 1267, (2010) 161

164 POS-37, FKP & NESY, Wed, 17:45 Modeling disorder in self-assembled monolayers with embedded dipoles Manuel Vieider 1, Luca Muccioli 2, Otello Roscioni 2, Egbert Zojer 1, Michael Zharnikov 3, Claudio Zannoni 2, Martin Stolterfoht 1 1 Graz University of Technology, Petersgasse 16, 8010 Graz, Austria 2 Universitá di Bologna, Viale Risorgimento 4, Bologna, Italy 3 University of Heidelberg, Im Neuenheimer Feld 253, Heidelberg, Germany We present a study using several techniques to simulate self assembled monolayers (SAM) on the Au(111) substrate. Accurate quantum mechanical simulations were used to parameterize the charge distribution on the molecules and to estimate the charge transfer to the gold surface caused by the binding of sulfur atoms. The results delivered the inputs for atomistic molecular dynamic simulations carried out with the LAMMPS code. The intermolecular interactions were described by the CHARMM27 force field, while for the interaction of the molecules and the gold atoms different force fields were tested. The main focus of this work is to provide an accurate description of the morphology of alkylthiols with and without a mid-chain ester functionalization. This particular class of molecules was chosen because the ester group provides an intramolecular electric dipole moment at a certain distance from the surface. We calculated the distribution of dipole orientations from equilibrated structures of monolayers in order to estimate the net-potential shift induced by those dipoles. Also, different surface coverages have been simulated to investigate the thermodynamic mechanisms of SAM islands formation and to quantify the intrinsic structural disorder by computing various order parameters. POS-38, GEP, Wed, 17:45 Alfred Wegener: Second Expedition to Greenland - A photographic window to the past Martin Leitner 1, Sabine Tschürtz 1, Gottfried Kirchengast 1, Heinrich Kranzelbinder 2, B. Prügger 2, Reinhard Krause 3, M. Kalliokoski 4, Ester Thórhallsdóttir 5 1 University of Graz (WEGC UniGraz), Leechgasse 25, 8010 Graz, Austria 2 Steiermärkisches Landesarchiv, Karmeliterplatz 3, 8010 Graz, Austria 3 Alfred Wegener Institute, Columbusstrasse, Bremerhaven, Germany 4 University of Turku, FI Turku, Finland 5 Fjölbrautask ĺi Snæfellinga, Iceland On several expeditions to Greenland, Alfred Wegener ( ) collected scientific data and took pictures on glass plates from landscapes and glaciers, the expedition equipment, the people and animals taking part on the expeditions as well as physical phenomena as dust storm, clouds or spherical light phenomena. Until the tragic end of the expedition in 1930, Wegener was professor at the University of Graz, and such a stock of about 300 glass plates stayed there. Chronologically the plates show the Danmark Expedition , the crossing of Greenland expedition with stop in Iceland , and the German Greenland Expedition This presentation gives an overview of pictures and dates from the Second Greenland Expedition, leaded by J.P.Koch in The aim of our work is to digitize all the plates for further studies. We present a selection from the second Greenland expedition, with the stopover in Iceland. For those made at Iceland in 1912 we present a comparison between past pictures an new one from the same viewing point made in

165 POS-39, LHS (PUS), Wed, 17:45 Kinder reisen durch die Wissenschaft Hans Eck 1, Sabine Hirschmugl-Gaisch 2 1 Kirchliche Pädagogische Hochschule Graz, Lange Gasse 2, 8010 Graz, Austria 2 Kindergarten Rosental an der Kainach, Hörggasstrasse 50, 8582 Rosental Kinder reisen durch die Wissenschaft ist ein Gemeinschaftsprojekt der Neuen Mittelschule Voitsberg, des Kindergarten Rosental a. d. K., dem Offenen Labor Graz in Kooperation mit der 7. fakultät der Karl-Franzens-Universität Graz und dem Interdisziplinären Zentrum für Fachdidaktik der Pädagogischen Hochschule Steiermark, mit dem Ziel, Kindern, wie Jugendlichen einen kreativ-interessanten und lustvoll-aktiven Zugang zu den unterschiedlichen naturwissenschaftlichen Disziplinen und Fachrichtungen zu ermöglichen. Unter dem Motto: Große helfen Kleinen werden in diesem Projekt Forschungsteams bestehend aus je einem Kindergarten-Kind und einem/er SchülerIn der Neuen Mittelschule gebildet, die auf dieser Reise durch die verschiedensten wissenschaftlichen Institutionen gemeinsam Aufgaben lösen, Experimente durchführen und dabei die Möglichkeit haben, ihre eigenen Forschungen zu betreiben. Betreut und angeleitet werden die Kinder und Jugendlichen in den einzelnen Modulen dabei jeweils von einem Wissenschaftler, oder Spezialisten seines Faches und einem/er StudentIn der naturwissenschaftlichen Fachrichtung. Den Auftakt der Reise durch die Wissenschaften bildete der erste Molekulare Kochkurs für Kindergartenkinder in Begleitung von SchülerInnen der NMS- Voitsberg unter dem Motto: Es dampft aus Kochtopf, Mund und Nase an der NMS-Voitsberg. Unter der Anleitung von 2- Haubenkoch Heinz Preschan, Dr. Helmut Jungwirth (Offenes Labor Graz) und einer Studentin der Biowissenschaften wurden in 3 Teams nicht nur dampfender, flüssiger Stickstoff und seine Auswirkungen auf Popcorn, Petersilie und Basilikum erforscht, sondern auch Joghurt-Bomben, Chilli-Rosmarin- Lollies und Kürbiskernschokolade hergestellt und mit großem Genuss gemeinsam verkostet. POS-40, LHS (PUS), Wed, 17:45 Forschendes Lernen als Methode der Kompetenzförderung Erich Reichel 1, Eduard Schittelkopf 1, Veronika Rechberger 1 1 Pädagogische Hochschule Steiermark, Hasnerplatz 12, 8010 Graz, Austria Für den Kompetenzerwerb im Physikunterricht bietet sich das forschende Lernen als hilfreiche Lernumgebung an. Es ermöglicht den Lerndenden an geeigneten Experimenten eigene Erfahrungen zu machen. Dadurch wird ihr Interesse am Thema geweckt und Raum für eigene Gedanken und Lösungsvorschläge im Unterricht geschaffen. Durch den wiederholten Einsatz im Unterricht können Teile der Handlungsdimension des österreichischen Kompetenzmodells vor allem im Bereich Erkenntnisse gewinnen abgedeckt werden. Vermittelnder Unterricht, in dem das Wissen als Produkt gesehen, das von der Lehrperson an die Lernenden weitergegeben wird steht dem forschenden Unterricht gegenüber, in dessen Rahmen Wissen als ein Prozess gesehen wird, in den der lernende Mensch eintaucht. Im Rahmen von forschendem Unterricht stoßen die Lernenden dabei auf Fragen, die bei Durchführung des vermittelnden Unterrichts nie auftreten würden. Von uns wird vierphasiger Unterrichtszyklus vorgeschlagen: Phase 1: Den Lernenden wird das Experiment vorgeführt und die Protokollierung ihrer Beobachtungen eingefordert. Phase 2: Die Lernenden führen das Experiment selbst durch und fixieren ihre Beobachtungen schriftlich. Phase 3: Die Beobachtungen führen zur Formulierung eigener Forschungsfragen. Phase 4: Die Lernenden planen und bearbeiten ihr eigenes Experiment oder eine darauf aufbauende Variation des Experiments zur Beantwortung ihrer persönlichen Forschungsfrage. Für die Dokumentation der Arbeiten durch die Lernenden und Überprüfung des Lernfortschrittes wurde ein eigener Protokollraster entwickelt. Unterrichtsbeobachtungen zeigten in unterschiedlichen Klassen auf unterschiedlichen Schulstufen, dass diese Methode zu mehr Eigenständigkeit und damit eine Kompetenzsteigerung der Lernenden bewirkt. 163

166 POS-41, LHS (PUS), Wed, 17:45 Mit Magnetfeldern hören Engelbert Stuetz 1 1 Johannes Kepler University, Altenberger Straße 69, 4040 Linz, Austria Am Projekt Mit Magnetfeldern hören arbeiteten alle Schülerinnen und Schüler zweier siebten Klassen mit. Ausgangspunkt des Projekts war diese Problemstellung: Trotz ihres Hörgerätes haben schwerhörige Menschen oft große Probleme, einen Sprecher zu verstehen. Das kann im Kino, im Theater, bei Vorträgen oder auch im Klassenzimmer der Fall sein. Schuld daran ist die Funktionsweise des Hörgerätes. Es macht nicht nur Erwünschtes lauter, sondern auch Nebengeräusche. Die Person hört nur noch ein Stimmgewirr und ist kaum mehr in der Lage, daraus die wichtigen Informationen zu filtern. Die Lösung ist eine einfache Anlage, die im Raum aufgebaut wird. Sie überträgt die Information mit Hilfe eines Magnetfeldes unmoduliert zur Telefonspule des Hörapparates. Das Projekt hatte diese Schwerpunkte: Eigenbau einer Induktionsanlage für einen großen Raum (Physiksaal) Klärung des physikalischen Hintergrundwissens zur Funktion der Induktionsanlage. Im Wesentlichen beschäftigten wir uns damit, wie man mit Magnetfeldern das Hören verbessern kann. Bau von Lern- und Experimentierstationen für eine Ausstellung Explorama. Wichtiger Bestandteil jeder Station war ein von Schülern ausgearbeitetes Arbeitsblatt zum Thema der jeweiligen Station. Das Explorama in Betrieb: Eine Woche lang konnten Schulklassen für jeweils eine Stunde das Explorama buchen. Die Lern- und Experimentierstationen waren dabei von Schülern der Projektklassen betreut. Die Evaluation zum Abschluss des Projekts gab uns Auskunft über den Erfolg des Projekts und über Verbesserungsmöglichkeiten bei zukünftigen ähnlichen Projekten an der Hamerlingschule. POS-42, LHS (PUS), Wed, 17:45 Papier erleben Stefanie Anna Tritthart 1, Beatrix Janits 1 1 HS 1 Deutschlandsberg, Schulgasse 16, 8530 Deutschlandsberg, Austria Papier ERLEBEN - das war das Thema des Projektes, an dem von November 2011 bis Jänner 2012 an der Hauptschule I in Deutschlandsberg gearbeitet wurde. Nicht nur die Physikund Chemiestunden in diesem Zeitraum werden den Schülerinnen und Schülern sicherlich längere Zeit in Erinnerung bleiben. Auch in den Schwerpunktgruppen der 7. und 8. Schulstufe wurde sehr intensiv an diesem Projekt gearbeitet. Die Highlights waren einerseits das Herstellen von handgeschöpftem Papier aus unterschiedlichen Materialien und Beigaben wie z.b. das Wespenpapier, andererseits die zahlreichen Versuche, die mit diesem Papier gemacht wurden. Es wurden beispielsweise verschiedene Papiersorten, darunter auch selbstgeschöpftes Papier, auf eine Herdplatte gelegt und genau beobachtet bzw. gemessen wann welches Papier verbrennt. Das Material Papier wurde in den Wahlpflichtfächern in den dritten und vierten Klassen unserer Schule unter die Lupe genommen und zur Herstellung unterschiedlichster Dinge verwendet, wie z.b. zum Bau von Papierflugzeugen und abgestumpften Ikosaedern (besser bekannt als Fußbälle) oder zur Herstellung von in Origami-Technik gefalteten Figuren. Eine Gruppe (Schwerpunkt Kunst) beschäftigte sich damit, Sessel mit Papiermosaiken zu überziehen. Im Zuge des technischen Schwerpunkts haben die Schüler mit Hilfe der Lego Mindstorms c Roboter das Wort Papier auf Papier geschrieben, wobei der Bau des Stifte-Halters und die Programmierung der einzelnen Buchstaben eine ganz schöne Herausforderung für die einzelnen SchülerInnen war. Der krönende Abschluss war die Präsentation des Projektes, bei der die Kreativität unserer Schülerinnen und Schüler gefragt war. Nicht die bei der Projektarbeit entstandenen Produkte allein, sondern auch das neu erworbene Wissen war Mittelpunkt der ansprechenden und gelungenen Präsentation. 164

167 POS-43, MBU, Wed, 17:45; This poster will also be presented on Thu. 20 th September 2012, 16:45-16:50; Ground based MAX-DOAS observations of tropospheric trace gases in San Salvador, El Salvador Carlos Armando Alberti 1, Benjamin Levy Mendoza 1, Carlos Rudamas 1 1 Universidad de El Salvador, Escuela de Física, 25 San Salvador, El Salvador High levels of air pollution in different Central Americas capital cities were reported a few years ago, being San Salvador metropolitan area the place with the highest concentration values of several pollutants. The high levels of these pollutants, in some measuring points, exceed the limit values established by the environmental law of the republic of El Salvador and also those established by EPA and WHO. In this work we report on levels of HCHO, O 4 and NO 2 obtained by using ground based Multi-Axis Differential Absorption Spectroscopy (MAX-DOAS) during a campaign performed in San Salvador on February The experimental set-up used in the DOAS-measurements consists of a home-made-telescope coupled to an spectrometer by using an optical fiber. The spectral resolution is around 1.2 nm. The diurnal behavior of NO 2 -dscd during the working days is characterized by an strong increase in the morning. It could be associated to emissions from vehicles during the rush hours. The obtained dscd values for HCHO are similar to the obtained by other authors in cities with higher population. The oxygen dimer O 4 levels were also measured in order to estimate the aerosol extinction. Similar trends are observed for HCHO and O 4. These results could be explained by a change in the aerosol extinction and meteorological conditions. POS-44, MBU, Wed, 17:45; This poster will also be presented on Thu. 20 th September 2012, 16:35-16:40; Bioequivalent Solid-State Dosimetry: Current Trends and Future Developments Michael Hajek 1 1 Vienna University of Technology, Stadionallee 2, 1020 Vienna, Austria Significant progress in radiobiology has refined our understanding of radiation-induced biological response at the cellular level and challenged the conventional macroscopic description of radiation action in favour of a nanodosimetric approach, which considers the spatial distribution of energy deposition along the particle track. The empirical correlation of luminescence properties of alkali halides and biological endpoints, such as DNA strand breaks in human fibroblasts, open up promising opportunities for bioequivalent solid-state dosimetry. Analysis of the nanodosimetric response to different radiation modalities using track structure theory and general multi-target, multi-hit models makes evident that the targets for radiation-induced effects in physical and biological systems are of comparable size. Availability of bio-equivalent dosimeters would represent a major progress in radiation protection, radiation biophysics and medical radiation physics, for it would allow to evaluate the biological effectiveness of radiations of different quality, largely independently of dose and dose rate. As a consequence, these studies directly support the development of new radiation protection concepts and thus concern a broad spectrum of applications ranging from environmental physics, medical diagnosis and therapy to human space exploration. 165

168 POS-45, MBU, Wed, 17:45; This poster will also be presented on Thu. 20 th September 2012, 16:30-16:35; Review and Cross-comparison of Matroshka Phantom Measurements in Different Compartments of the International Space Station Christina Hofstätter 1, Michael Hajek 1, Thomas Berger 2, Pawe l Bilski 3, Daniel Matthiä 2, Monika Puchalska 4, Andrea Zechner 1, Günther Reitz 2 1 Vienna University of Technology, Stadionallee 2, 1020 Vienna, Austria 2 German Aerospace Center, Linder Höhe, Köln, Germany 3 The Henryk Niewodniczaski Institute of Nuclear Physics, 152 Radzikowskiego Str., Kraków, Poland 4 Chalmers University of Technology, SE Gothenburg, Sweden Astronauts working and living in space are exposed to considerably higher doses and different qualities of ionizing radiation than people on ground. Matroshka, a European Space Agency experiment under coordination of the German Aerospace Centre, is the most comprehensive effort so far in radiation protection dosimetry in space using an anthropomorphic upper torso phantom known from radiotherapy treatment planning to map the dose distribution throughout a simulated human body on board the International Space Station (ISS). Absorbed dose and dose equivalent measured by nuclear track detectors and miniature thermoluminescence dosimeters embedded in a regular grid and at the site of vital organs are combined with detailed numerical models to allow for estimation of effective dose. Monte Carlo simulations using the transport codes FLUKA and GEANT4 that provide calculations of particle fluence and dose for various radiation environment conditions further support the experiment and improve cancer risk projections for future long-term space exploration beyond the Earths magnetosphere. The paper presents a review and cross-comparison of data acquired during four missions between January 2004 and March 2011, in which the phantom has been installed in different compartments of the Russian and Japanese segments of the ISS: outside and inside Zvezda, inside Pirs and inside Kibō. 166

169 POS-46, MBU, Wed, 17:45; This poster will also be presented on Thu. 20 th September 2012, 16:40-16:45; Korrelation relativer Feuchte und Stromumwandlungskoeffizient der Dünnschicht-Photovoltaik Maryam Nikbakhti 1, Marcus Rennhofer 1, Viktor Schlosser 1, Karl Berger 2, Philipp Weihs 3, Jochen Wagner 3, Roman Leidl 2, Dietmar Baumgartner 4 1 University of Vienna, Strudlhofgasse 4, 1090 Vienna, Austria 2 AIT Austrian Institute of Technology GmbH, Giefinggasse 2, 1210 Vienna, Austria 3 University of Natural Resources and Life Sciences, Peter Jordan Strasse 82, 1190 Vienna, Austria 4 Observatory Kanzelhöhe, KFU-Graz, Treffen 9521, Austria Im Rahmen des nationalen Projektes PV-SPEC wurden an klimatisch und meteorologisch unterschiedlichen Standorten verschiedene Modultypen (Mono, CdTe und a-si) hinsichtlich ihres Verhaltens bezüglich spektraler Änderungen des einfallenden Sonnenlichtes und meteorologischer Parameter untersucht. Schlussfolgerungen über die Umwandlungseffizienz der Module konnten getroffen werden. Dazu wurden Module jeder Type mit 35 Neigungswinkel nach Osten, Süden und Westen an einem Hochgebirgsstandort (1600 m) und einem Flachlandstandort (170 m) über einen Zeitraum von 3 Jahren untersucht. Es wurde die Korrelation zwischen den gemessenen Umgebungsvariablen, der Einstrahlung, den spektralen Bestrahlungsstärkewerten und der Umwandlungseffizienz η, der Module untersucht. Schwerpunkt der präsentierten Arbeit ist der Einfluss der relativen Feuchtigkeit der Luft sowie globale Einstrahlung E und spektral aufgelöste Einstrahlung E(λ) auf elektrischen Parameter und Temperatur, Umgebungsbedingungen. Weiters wurde die Stärke der Alterung der Module innerhalb des Messzeitraumes bestimmt. Eine Veränderung der Wetter- oder feuchtebedingten spektralen Anteile der auf ein Modul treffenden Einstrahlung (großteils Rayleigh-Streuung) hin zum Roten oder Blauen Spektralbereich bedingt eine unmittelbare Änderung der Umwandlungseffizienz: über die spektrale Empfindlichkeit (SR) beeinflusst eine solche Änderung den im Modul aus dem Licht generierbaren Strom. Es wurden die Einflüsse der relativen Feuchtigkeit auf Bodenniveau in diesem Zeitraum mit jenen der relativen Feuchtigkeit des atmosphärischen Höhenprofils verglichen. Durch eine Simulation wurden die theoretischen Maximalwerte der Feuchteabhängigkeit mit den gemessenen Werten verglichen. Die Analyse aller Parameter gibt ein Maß für die Abhängigkeit der system- und klimarelevanten elektrischen Messgrößen von der relativen Feuchtigkeit der Luft. POS-47, OGD, Wed, 17:45 AFM investigation of kraft pulp fiber swelling in controlled humidity Christian Ganser 1, Robert Schennach 1, Christian Teichert 2 1 Graz University of Technology, Petersgasse 16, 8010 Graz, Austria 2 Montanuniversität Leoben, Franz-Josef Strasse 18, 8700 Leoben, Austria Kraft pulp fibers are wood fibers from softwood, typically spruce and pine, which are the main constituent for so called kraft paper. Kraft paper is used mainly for packaging applications, where a high strength is required. In this work, the swelling behavior of spruce kraft pulp fibers is investigated by atomic force microscopy (AFM). To perform this task, the AFM was equipped with a fluid cell and a setup where the relative humidity inside the fluid cell can be controlled. The setup enables to select any humidity value between approximately 5% and 80% relative humidity. With this setup, a change in surface morphology of the scanned area could be observed. Furthermore, the evolution of the characteristic surface wrinkles of dried pulp fibers with increasing humidity was quantified in two different ways. One way is to measure the distance between the surface wrinkles, the other to determine their height. It could be shown that the distance between the wrinkles is increasing, whereas the height is decreasing. This means that the surface is becoming smoother when the fiber is swelling, which is best observed on a completely wet fiber. Supported by Mondi, Kelheim Fibres and the Christian Doppler Research Society, Vienna, Austria. 167

170 POS-48, OGD, Wed, 17:45 Kinetic Monte Carlo Simulations of Nucleation and Thin Film Growth of Hexaphenyl on Amorphous Mica Christoph Gleichweit 1, Adolf Winkler 1, Levent Tümbek 1, Karin Zojer 1 1 Graz University of Technology, Petersgasse 16, 8010 Graz, Austria Ultra-thin films of para-hexaphenyl on sputter amorphized mica(001) exhibit the surprising behavior of forming bimodal island size distributions. Small islands were observed besides bigger ones. It is believed that as long as the sample is in ultra-high vacuum, there exists a 2D-gas phase between the bigger islands, which vanishes by nucleating a lot of small islands when exposed to air. Probably due to the adsorption of water on the surface the energetics of monomers on the surface change and islands form. This behavior is named adsorbate induced subsequent nucleation. Using KMC simulations this effect was tried to be reproduced with the objective of extracting information about the critical cluster size and the island size distributions. For this reason an algorithm for edge hopping that respects also the critical island size was developed. The system initializes by starting with an initial concentration of monomers on the surface. These monomers suddenly start to diffuse and hence nucleate islands with the specified critical nucleus size and diffusion barriers. Particles that are part of stable clusters are not anymore allowed to detach from the islands. The simulation stops as soon as all molecules are incorporated into islands. The resulting island densities were compared to the experimental results. It turned out that a critical island size of i = 7 matches the experiments. Moreover, the island size distributions were compared to the ones obtained from the AFM images and were found to agree qualitatively. POS-49, OGD, Wed, 17:45 Susceptibility measurements of Ni nanostructures on Cu(110) Michael Hohage 1, Mariella Denk 1, Richard Denk 1, Robert Mittermair 1, Daniel Queteschiner 1, Lidong Sun 1, Peter Zeppenfeld 1 1 Johannes Kepler University, Altenberger Straße 69, 4040 Linz, Austria A set-up capable of in-situ magnetic susceptibility measurements is introduced. The magnetic measurements are based on a Reflectance Difference Spectrometer (RDS), by exploiting its high sensitivity to the polar Magneto-Optic Kerr Effect (RD-MOKE). The external magnetic field is created by a magnetic coil placed in close vicinity of the sample. For susceptibility measurements a sinusoidal magnetic field is applied to the sample. The response of the RD-MOKE signal at photon energies between 1.5 and 5 ev is frequency analyzed and the amplitudes and phases of the first and higher harmonics are obtained. The capability of this set-up is demonstrated for ultra thin Ni films on Cu(110)-(2 1)O. Comparison to regular RD-MOKE shows that the signal-to-noise ratio has been substantially improved. The analysis of the first and higher harmonics allows studying magnetic phase transitions in more detail: The spin reorientation transition (SRT) occurring at a Ni coverage of 9 ML on Cu(110)-(2 1)O and the behavior of Ni-films around the Curie temperature have been investigated and the ferromagnetic and (quasi-)paramagnetic behavior has been identified. In the ferromagnetic regime hysteresis curves have been obtained. The improved signal allows us to investigate the magnetic properties of CoTMPP films on Cu(110)-(2 1)O. At photon energies of 2.7 ev where a strong optical transition occurs also the susceptibility shows a peak. Thus we can clearly correlate the magnetic susceptibility to the optical transitions of the films. 168

171 POS-50, OGD, Wed, 17:45 Dynamic plowing lithography and 6P thin film growth on graphene investigated by atomic force microscopy Markus Kratzer 1, Stefan Klima 1, Borislav Vasic 2, Aleksandar Matkovic 2, Andreas Pavitschitz 1, Uros Ralevic 2, Djordje Jovanovic 2, Christian Ganser 1, Christian Teichert 1, Rados Gajic 2 1 Montanuniversität Leoben, Franz-Josef Strasse 18, 8700 Leoben, Austria 2 Institute of Physics, Pregrevica 118, P. O. Box 68, Belgrade, Serbia For the design of novel graphene based devices specific modifications and manipulations of graphene are essential. The desired properties might be achieved by selective straining and/or multistacking of graphene. As a model system we investigated the growth morphology of the rodlike para-hexaphenyl (6P) molecule on as prepared and dynamic plowing lithography (DPL) modified graphene. As substrate exfoliated graphene flakes on silicon dioxide (SiO 2 ) were used. The DPL of the graphene was performed by bringing the very hard diamond coated tip of a vibrating atomic force microscopy (AFM) probe into close proximity to the substrate. Depending on the chosen experimental parameters the interaction forces between tip and substrate lead either to a local deformation or even to cutting of the graphene flake. The 6P was deposited by means of hot wall epitaxy at sample temperatures above room temperature. The resulting film morphologies on the unaltered and DPL modified graphene were investigated via atomic force microscopy. While on the SiO 2 only 6P islands consisting from upright standing molecules are found there are additional needle like structures exclusively found on the graphene. POS-51, OGD, Wed, 17:45 Morphological investigations of viscose fibers by atomic force microscopy Patrice Kreiml 1, Christian Ganser 1, Robert Schennach 1, Christian Teichert 2 1 Graz University of Technology, Petersgasse 16, 8010 Graz, Austria 2 Montanuniversität Leoben, Franz-Josef Strasse 18, 8700 Leoben, Austria Viscose fibers are used in textiles, hygiene products, and medical applications. The fibers are spun from a viscose solution of cellulose. Their cross-section is shaped by spinning the viscose solution through a spinneret, thus forming the fibers. The water absorption is an important property in the applications mentioned. Here, two samples of viscose fibers were investigated, which showed different behavior under water absorption. The samples were produced under similar conditions and therefore morphological investigations were of interest. In this study, the morphology of samples with high and low water absorption were compared. The surface was investigated by atomic force microscopy (AFM) in tapping mode. A comprehensive roughness analysis, including height-height correlation function (HHCF), showed no significant differences in the roughness parameters. On the surface of all samples, trenches could be observed and further investigation of these trenches was conducted. Depth and length distribution were similar, but the angle distribution, as well as trench density were different. From this result we conclude that the trench alignment and density are the main differences in morphology between the two fiber types, which might explain their different water absoprbtion. Supported by Kelheim Fibres and the Christian Doppler Research Society, Vienna, Austria. 169

172 POS-52, OGD, Wed, 17:45 Growth and structure of WOx nanolayers on bare Cu(110) and Cu(110)(2 1)O surfaces David Kuhness 1, Martin Denk 1, Margareta Wagner 1, Svetlozar Surnev 1, Giovanni Barcaro 2, Luca Sementa 2, Fabio Negreiros 2, Alessandro Fortunelli 2, Falko Netzer 1 1 University of Graz, Universitätsplatz 5, 8010 Graz, Austria 2 CNR-IPCF, Istituto per i Processi Chimico-Fisici del CNR, Pisa, Italy Tungsten trioxide (WO 3 ) is deposited through direct thermal evaporation of WO 3 powder under ultra high vacuum (UHV) conditions onto a bare Cu(110) and onto a Cu(110)(2 1) oxide reconstructed crystal surfaces at room temperature. The growth characteristics have been documented with scanning tunnelling microscopy (STM), low energy electron diffraction (LEED) and synchrotron x-ray photoemission (XPS) systematically through the range of low, i.e. 0.1 monolayer (ML) to high (2.0 ML) coverage of WOx and annealing of the sample to temperatures from room temperature to 700 C. Several phases of WOx structures have been observed and analyzed. Under particular growth conditions, i.e. 0.6 ML WO 3 and a sample temperature of 300 C a well ordered single phase surface with a quasi-square structure could be prepared onto the Cu(110)(2 1)O surface. As the unit cell dimensions of this phase are similar to those of the (ac) projected surface of CuWO 4 single crystals a model with a CuWO 4 stoichiometry has been proposed and analyzed in DFT calculations. This work has been supported by the ERC Advanced Grant SEPON. CPU time at the CINECA supercomputing center via the ISCRA UT-Ox project is gratefully acknowledged. POS-53, OGD, Wed, 17:45 Adsorption of Xylan onto Bleached Softwood Fibers Albrecht Miletzky 1, Petra Wollboldt 2, Manuel Punz 3, Hansjörg Weber 4 1 Graz University of Technology, Petersgasse 16, 8010 Graz, Austria 2 Kompetenzzentrum Holz GmbH, Altenberger Strasse 69, 4040 Linz, Austria 3 Zellstoff Forschung, Analytik, Lenzing AG, Werkstrasse 2, 4860 Lenzing, Austria 4 Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria Besides cellulose, hemicelluloses or polyoses (e.g. xylan) are the most common polymers in higher plants and wood. Hardwood contains up to 35% of xylan. Due to chemical pulping to remove lignin from the wood matrix and to provide fibers for the production of paper polysaccharides are getting dissolved and degraded in the cooking liquor. This leads in a reduction of the physical strength properties of the paper. The aim of this work is to redeposit different xylans on the surface of pulp fibers to improve their mechanical properties. At first, influencing variables such as ph, temperature, ionic strength, pulp consistency, concentration of xylan in the suspension and the dwell period during adsorption were investigated. After different trials the pulp was hydrolyzed to its sugar monomers and analyzed with high-pressure liquid chromatography (HPLC) and nuclear magnetic resonance spectroscopy (1H NMR). The amount of xylan could be enhanced up to 7% points on bleached softwood kraft pulp. The molecular weight of the xylan and the temperature showed the most effect of adsorption. The determination of the zeta potential of the fibers and the different xylans will be shown too. The effect of the surface and total charge of the substrate is of interest to get more information about the attractive and repulsive forces as well as the mechanisms between the fibers and the colloidal dispersed xylan molecules during adsorption. The electrical properties of the fibers will be analyzed by using kelvin probe force microscopy (KPFM) as well. 170

173 POS-54, OGD, Wed, 17:45 The contact charging of insulators by atomic force microscopy Monika Mirkowska 1, Markus Kratzer 1, Christian Teichert 1, Helmut Flachberger 1 1 Montanuniversität Leoben, Franz-Josef Strasse 18, 8700 Leoben, Austria Detailed knowledge on the contact charging behaviour of dielectric materials is of great interest for technological applications like tribocharging separation of mineral additives. As a model system, we investigated the contact charging between quartz or calcite and high-density polyethylene (HDPE). An attempt was made to measure the electric charging of microsize single particles upon contact with well-defined surfaces (monocrystallie surfaces of the same materials as well as with HDPE surfaces). For this purpose, the particles were glued to the ending of AFM cantilevers and force distance (F-d) curves were measured under controlled temperature and humidity conditions. Additional, Kelvin Probe Force Microscopy (KPFM) and Electrostatic Force Microscopy (EFM) measurements were carried out in order to map local electrical changes at the surface. POS-55, OGD, Wed, 17:45 Anisotropic growth of ultrathin Mn-oxide nanostructures on Ag(100) Thomas Obermüller 1, Svetlozar Surnev 1, Alessandro Fortunelli 2, Wolfram Steurer 1, Falko Netzer 1 1 University of Graz, Universitätsplatz 5, 8010 Graz, Austria 2 CNR-IPCF, Istituto per i Processi Chimico-Fisici del CNR, Pisa, Italy Low-dimensional nanostructures of transition metal oxides on well-defined metal surfaces have novel physical and chemical properties which differ drastically from their bulk counterparts. Due to their novel properties, these nanostructures have opened up a new field of fundamental research and they are also of particular interest for a wide variety of potential application in nanotechnologies, such as in heterogeneous catalysis, electronic devices and corrosion protection. Here we report the formation of uniaxially ordered Mn-oxide nanostripes with almost macroscopic dimensions (> 1000nm) in length on a Ag(100) substrate. The growth of ultra-thin films of manganese oxide on a Ag(100) single crystal surface has been studied using STM, AFM and LEED techniques. Submonolayer coverages of Mn-oxide have been deposited by thermal evaporation under either UHV conditions or in oxygen atmosphere followed by a post-oxidation step. As a function of the chemical potential of oxygen in the post-oxidation step, three different Mn-oxide phases have been detected. While oxygen pressures above mbar lead to a randomly distribution of hexagonally ordered MnO X islands with a triangular shape, a highly anisotropic growth of long and narrow (2 1) stripes forming a network of Mn-oxide islands is observed at oxygen pressures around mbar. For lower oxygen pressures, (2 2) multilayered rectangular islands are found. The physical origin of this anisotropic growth is discussed in a growth model based on the atomic structure of the (2 1) oxide phase. Work supported by the ERC Advanced Grant SEPON 171

174 POS-56, OGD, Wed, 17:45 Surface Chemistry Chamber for analysis of Oxides Jiří Pavelec 1, Michael Schmid 1, Ulrike Diebold 1, Gareth Parkinson 1 1 Vienna University of Technology, Wiedner Hauptstrasse 8-10/134, 1040 Wien, Austria A new UHV chamber for the investigation of oxide surface chemistry (e.g. In 2 O 3, SnO 2, Fe 3 O 4, perovskites, TiO 2, ZrO 2 ) is described. The combination of a specially designed sample mount design and a molecular beam dosing setup solves difficulties associated with performing Temperature Programmed Desorption experiments on bulk oxide samples. Further spectroscopic techniques available on the system include Ultra Violet Photoelectron Spectroscopy, X-ray Photoelectron Spectroscopy using a monochromatic X-ray source, Low Energy Electron Diffraction, and Ion Scattering Spectroscopy. Utilization of a liquid helium flow cryostat allows us to follow reactions from K, but also allows physisorption of inert gasses such as Kr, a useful probe of surface defects, and also the basis of the Buffer Layer Assisted Growth (BLAG) technique for the in-situ preparation of monodisperse nanoparticles. An Electro spray Deposition System is used for the deposition of non-volatile organic molecules that otherwise cannot be studied in UHV. This surface chemistry instrument provide an ideal compliment to our existing STM based studies. POS-57, OGD, Wed, 17:45 Microscopical electrical investigations of grain boundaries in ZnO varistor ceramics Andreas Pavitschitz 1, Michael Hofstaetter 1, Peter Supancic 1, Christian Teichert 1 1 Montanuniversität Leoben, Franz-Josef Strasse 18, 8700 Leoben, Austria Varistors are nonlinear voltage dependent ceramic resistors used to suppress and limit transient voltage surges. The most common material for varistors is doped polycristalline ZnO which shows highly non-linear current-voltage characteristics with rapidly decreasing resistance above a specific voltage. This effect is caused by so called Schottky barriers at the grain boundaries. Therefore, investigation of the electrical properties of the individual grain boundaries is essential for the understanding of the varistor effect and the improvement of varistor materials. In this study, the electrical properties of ZnO multilayer varistors (MLV) were investigated on the microscopic scale employing conductive atomic-force microscopy (C-AFM), Kelvin probe force microscopy (KPFM), and KPFM with biased MLV electrodes (biased KPFM). The electrical properties of individual grain boundaries were directly measured with a micro-four-point probe measurement setup. Additionally, the crystallographic orientation of the single grains was determined with electron backscatter diffraction (EBSD). The electronic properties were associated with the crystallographic orientation data obtained from EBSD. Employing KPFM on a MLV with an applied bias between the electrodes reveals a step-like voltage drop with steps at the grain boundaries. The relative height of these steps is not uniform. Also a dependence of the relative step-height on the direction of the applied bias was observed. 172

175 POS-58, OGD, Wed, 17:45 Structure Solution of Surface Induced Crystal Structures: Selected Examples of Calamitic Conjugated Molecules Alexander Pichler 1, Markus Neuschitzer 1, Michael Dohr 1, Alfred Neuhold 1, Armin Moser 1, Günter Schwabegger 2, Helmut Sitter 2, Clemens Simbrunner 2, Theo Dingemans 3, Eric G lowacki 2, Mihai Irimia-Vladu 2, Johannes Gierschner 4, Yves Geerts 5, Michele Sferrazza 5, Roland Resel 1 1 Graz University of Technology, Petersgasse 16, 8010 Graz, Austria 2 Johannes Kepler University, Altenberger Straße 69, 4040 Linz, Austria 3 Faculty of Aerospace Engineering, Kluyverweg 1, 2629 HS Delft, Netherlands 4 Madrid Institute for Advanced Studies, C/ Faraday 9, Ciudad Universitaria de Cantoblanco, 28049, Madrid, Spain 5 Université Libre de Bruxelles, Campus de la Plaine, 1050 Bruxelles, Belgium Organic molecules in thin films show often specific crystal structures which are different from the known single crystal structures. Such surface-induced crystal structures are formed due to the presence of a surface during the crystallisation process. Within this work we present a specific approach to solve surface induced crystal structures. The solution is based in a first step on the determination of the crystallographic lattice by indexing the observed Bragg peaks of grazing incidence x-ray diffraction measurements. In a second step the molecular packing within the crystallographic unit cell is determined by a rigid body refinement of the molecular structure against the experimentally obtained intensities of the Bragg peaks. To check the reliability of the approach the already known crystal structure of dioctylbenzothieno-benzothiophene (C 8 -BTBT) will be investigated. As a result of the work the surface induced crystal structures of three different conjugated molecules will be presented: the well-known dye Tyrian Purple (TP) crystallised on a polyethylene surface, the molecule ternaphthalene (NNN) grown on thermally oxidised silicon wafers and phenylene-butoxyphenyl-acrylonitrile (DBDCS) grown on glass surfaces. POS-59, OGD, Wed, 17:45 Influence of potassium on the nucleation and growth of para-hexaphenyl on mica Bernhard Putsche 1, Adolf Winkler 1 1 Graz University of Technology, Petersgasse 16, 8010 Graz, Austria Semiconducting oligomers, such as para-hexaphenyl (6P), are attractive candidates as active layer material for organic electronic devices. A model system to investigate the growth parameters is 6P on mica. Adsorbed on freshly cleaved mica, 6P forms needlelike islands of flat lying molecules on top of a wetting layer. Previous investigations have shown that surface modifications, like sputtering, lead to the formation of islands of standing molecules and dewetting. When mica is cleaved, the sample always splits along its potassium layer and a half monolayer of potassium remains on each face. This contribution describes the effects of an increased amount of potassium on the thin film layer growth of 6P. Performing the measurements in ultra-high vacuum ensured precisely controlled conditions for the experiments. 6P was evaporated by using a Knudsen cell and the amount of evaporated material was determined by a quartz microbalance. Potassium was deposited by using a SAES Getter source. Thermal desorption spectroscopy (TDS, in-situ) and atomic force microscopy (AFM, ex-situ) were the main analytical methods to describe the effects of potassium on the growth of the 6P molecules. Auger electron spectroscopy (AES) was applied for chemical analysis of the mica sample before and after the potassium deposition. It turned out that pre-adsorbed potassium causes dewetting and the formation of islands of standing 6P molecules. AES and TDS measurements revealed that proper potassium adsorption/desorption cycles are leading to a saturated potassium coverage of one monolayer on mica, which is stable up to 1000K. 173

176 POS-60, OGD, Wed, 17:45 Thin cellulose films as model systems for paper-fibres Sebastian Rohm 1, Robert Schennach 1 1 Graz University of Technology, Petersgasse 16, 8010 Graz, Austria Paper fibres mainly consists of long cellulose and hemicellulose molecules. To investigate how these molecules are attracted to each other thin cellulose-layers are spin-coated on a 2x2cm 2 siliconwafer. Since Cellulose is difficult to solve into a solvent, first Trimetylsilycellulose (solved into Toluol) is spin-coated on the surface which then is transformed to cellulose by hydrolysis. This spin-coating process is done 4 times to get a layer-thickness of about 200nm. For swelling these wafers are laid into distilled water. To measure ionic influences some wafers are also swelled into water with 0.1mol/l CaCl 2. After that two cellulose-surfaces are laid against one another and put into a dryer. There the physical bonds between these surfaces are formed while the water evaporates. After 4 hours of drying the thin films are joint and z-strength-tests can be performed. For that, the wafers are fixed on the silicon-side and a tensile-test is made. The maximum force, the strain and the energy needed is measured in this experiment. The advantage of this method is, that only physical bonds like van der Waals-, Ionic- and Hydrogenbonds are contributing. In addition, the films are investigated with an Atomic-Force-Microscope, before and after the strengthtests, to find out where the molecules form bonds with each other. To measure the influence of hemicellulose-molecules, xylan-layers are spin-coated on the cellulose-layer and the same measurements are performed. POS-61, OGD, Wed, 17:45 Initial growth of Rubicene on Silicon Oxide Boris Scherwitzl 1, Adolf Winkler 1, Walter Lukesch 1 1 Graz University of Technology, Petersgasse 16, 8010 Graz, Austria In the course of the last decades organic microelectronic devices became of increasing importance. The use of organic or hybrid organic devices yields advantages in a variety of fields of application. Flexible displays or solar cells are already notable examples of present day technology. Inventing new and improving existing devices requires full understanding and best control of building processes. Therefore studies of the initial stages of organic thin film growth are essential. This contribution describes the behavior of rubicene film growth on silicon oxide with respect to sample treatments. Physical vapor deposition was the method of choice for creating films from sub-monolayers up to multilayers. Rubicene was evaporated by using a Knudsen cell and the amount of evaporated material was determined by a quartz micro balance. Auger Electron Spectroscopy (AES) was applied for chemical analysis and proved homogeneity of the sample. Thermal Desorption Spectroscopy (TDS) was the main analytical method along with Atomic Force Microscopy (AFM) to determine the behavior of the molecules on the substrate. The surface was intentionally altered by argon sputtering and carbon deposition. Performing the measurements in ultra-high vacuum (UHV) ensured precisely controlled conditions for the experiments, although the AFM measurements were subsequently done ex-situ. It could be shown that the rubicene formation, especially the thermal stability and dewetting, depends strongly on the substrate conditions. Furthermore, it could be demonstrated by AES and TDS that on a clean silica substrate the first monolayer of rubicene dissociates upon heating the surface. 174

177 POS-62, OGD, Wed, 17:45 Bismuth surface phonon modes from helium atom scattering experiments Anton Tamtögl 1, Michael Mayrhofer-Reinhartshuber 1, Patrick Kraus 1, Davide Campi 2, Giorgio Benedek 2, Wolfgang Ernst 1 1 Graz University of Technology, Petersgasse 16, 8010 Graz, Austria 2 Universitá degli Studi di Milano-Bicocca, Via Roberto Cozzi 53, Milano, Italy The semimetal bismuth (Bi) is a prime candidate for the study of quantum size effects in solids[1]. Only recently anisotropies in conductivity measurements of Bi have been observed[2]. Whereas Bi bulk properties have been analyzed very well open questions concerning the lattice dynamics of the Bi surfaces remain[1]. Helium Atom Scattering (HAS) allows the investigation of elastic as well as inelastic phenomena associated with the shape and changes of the electron density corrugation at the Bi(111) surface[3]. Therefore, using inelastic HAS measurements the surface phonon dispersion of Bi(111) could be determined for the first time. In both high-symmetry directions the phonon dispersion exhibits a Rayleigh mode, a strong longitudinal resonance and a nearly dispersionless branch at approximately 4 mev. A comparison of the phonon dispersion with calculations from density functional perturbation theory show that the longitudinal resonance exhibits the largest amplitude in the second layer and the flat phonon branch originates even from an atomic displacement in the third layer. The observation of this subsurface modes in helium scattering is only possible due to the electron phonon-coupling. Thereby oscillations of the electron charge density above the first layer are caused by the movement of the atoms in subsurface layers. [1] P. Hofmann, Prog. Surf. Sci. 81 (2006) 191. [2] S. A. Parameswaran et al., Nat. Phys. 8 (2012) 7 [3] M. Mayrhofer-Reinhartshuber et al., J. Phys.: Cond. Matt. 24 (2012) POS-63, OGD, Wed, 17:45 Attachment limited versus diffusion limited nucleation of organic molecules: Hexaphenyl on sputter-modified mica Levent Tümbek 1, Adolf Winkler 1 1 Graz University of Technology, Petersgasse 16, 8010 Graz, Austria The nucleation and growth of point-like particles, like metal atoms, is usually discussed in the framework of diffusion limited aggregation (DLA). In this contribution we demonstrate that for extended particles, like for the rod-like organic molecules hexaphenyl (6P), this nucleation scenario does not always hold. The reason is that the condition of an incorporation probability of unity is not fulfilled any longer for these monomers. A special characteristics of DLA is that the island density N scales with N = c(r/d) (i/(i+2)), with R: deposition rate, D: diffusion rate, and i: critical island size. For this scenario the critical island size i, which can be easily obtained from the slope in the plot lnn vs lnr, should vary between 0.33 and 1. However, for the island growth of 6P on especially sputter-amorphized mica we obtain a slope of 1.4. Indeed, this result can be explained by assuming that the nucleation is governed by attachment limited aggregation (ALA). In this case the island density N scales with N = c(r/d) (2i/(i+3)), and i can vary between 0.5 and 2. Consequently, a critical island size of 7 is obtained in this case. The crucial parameter for the growth mode is the roughness of the substrate surface, as induced by ion sputtering. With increasing surface roughness the diffusion probability of the molecules decreases and the growth mode changes from ALA to DLA. 175

178 POS-64, OGD, Wed, 17:45 Displacement and Replacement in Organic Heterostructures Thomas Ules 1, Eva Reinisch 1, Markus Ostler 2, Michael Ramsey 1, Georg Koller 1 1 University of Graz, Universitätsplatz 5, 8010 Graz, Austria 2 University Erlangen Nürnberg, Erwin-Rommel-Strasse 1, Erlangen, Germany In this LEED/Angle Resolved UPS study an heterostructure system is presented which shows a counter intuitive reversible replacement of two different organic molecules at the molecule substrate interface. The organic rod like molecule sexiphenyl (6P) forms a well ordered monolayer on Ag(110) which is clearly characterised by its valence band emissions and its geometric structure. Valence band tomography of the π orbitals show no evidence of backdonation to the 6P LUMO and that 6P is in its twisted confirmation with its long molecular axes aligned perpendicular to the substrate atomic rows. Upon the deposition of pentacene (5A) on it, a density of states appears at the Fermi edge. Fermi surface maps identify this intensity as the ex-lumo of 5A filled via backdonation from the substrate. This, together with the fact that 6P emissions are still dominant, suggests that 5A has gone to the interface. Extraordinarily, on ramping the temperature the 6P features first disappear and then reappear at the temperature of desorption of the 5A/Ag(110) monolayer. This de/re-wetting is also observed with LEED where de-wetting of 6P results in the appearance of a well ordered 5A monolayer LEED pattern which, at the 5A desorption temperature, changes completely to the 6P monolayer pattern. That the chemisorbed 5A desorbs before the physisorbed 6P is apparently counterintuitive and will be discussed in terms of the energetics of de-wetting (3D island formation) and wetting monolayers. Acknowledement: This work is supported by the Austrian Science Foundation FWF. POS-65, OGD, Wed, 17:45 Reversible transitions between surface reconstructions on SrTiO 3 Zhiming Wang 1, Stefan Gerhold 1, Michael Schmid 1, Ulrike Diebold 1 1 Vienna University of Technology, Wiedner Hauptstrasse 8-10/134, 1040 Wien, Austria SrTiO 3 as an archetypical perovskite oxide has attracted intense interest in diverse fields ranging from fundamental solid-state physics to photocatalysis chemistry, material science, as well as electronics applications. Related research has become even more exciting since the recent discovery of a 2DEG at the SrTiO 3 surface and interfaces. In all these applications the structural and electronic surface properties are of vital importance, yet perovskite surfaces are notoriously complex and hard to control. Here we report investigations on SrTiO 3 surfaces using STM, LEED and XPS. Atomically well-defined SrTiO 3 (110) surfaces can be obtained by Ar + sputtering followed by annealing. Mono-phased reconstructions are obtained, and the evolution between different phases can be tuned reversibly by depositing Sr or Ti. The tuning mechanisms are revealed as a chemical concentration-driven process on the surface. 176

179 POS-66, OGD, Wed, 17:45 Investigation of the surface charge of Viscose Fibres by XPS and ATR Frederik Weber 1, Robert Schennach 1, Rene Eckhart 1, Georg Koller 2, Ingo Bernt 3 1 Graz University of Technology, Petersgasse 16, 8010 Graz, Austria 2 University of Graz, Universitätsplatz 5, 8010 Graz, Austria 3 Kelheim Fibres GmbH, Regensburger Strasse 109, Kelheim, Germany The primary objective within the CD-Laboratory is to get a better understanding of the mechanism how paper fibres stick together. There are five types of interactions that determine the specific joint strength in the contact zone between the fibres: mechanical interlocking, interdifusion, induced dipoles, van der waals forces and hydrogen bonds. Regenerated cellulose fibres like viscose fibres are in principle chemically identical to wood pulp fibers. They are available with well defined parameters like cross section, fibre length or fibre width and in contrast to wood pulp fibres, are rather smooth, without fibrils on the surface. Therefore, they are model-fibres which are perfect for investigating the mechanism of fibre-fibre bonds and to get a better understanding how paper fibres stick together and perform in a paper sheet. A big advantage of viscose fibres is the feasibility to mix several additives to them. Thereby defined anionic as well as cationic fibres can be achieved. Without mechanical interlocking, viscose fibres can be used to investigate the influence of surface charges on the bond strength. Four kinds of fibres were investigated by X-ray photoelectronspectroscopy (XPS) and attenuated total reflection spectroscopy (ATR). The investigated fibres only differ in charge but have the same cross section and dimensions. Two anionic and a cationic fibre were investigated using the regular viscose fibre as a reference. Via XPS and ATR the amount of anionic and of the cationic additives were investigate to get an idea of the charge density of all used fibres. POS-67, OGD, Wed, 17:45 Selective Photo-induced Cross-linking of Polynorbornens: Towards the Fabrication of Polymer 2D- and 3D- Microstructures Archim Wolfberger 1, Thomas Griesser 1, Ute Daschiel 1,2, Volker Schmidt 3, Abdellatif Jerrar 4, Christian Teichert 4, Wolfgang Kern 1 1 University of Leoben, Otto-Glöckel-Strasse 2, 8700 Leoben, Austria 2 Polymer Competence Center Leoben GmbH, Roseggerstrasse 12, 8700 Leoben, Austria 3 Joanneum Research GmbH Weiz, Franz-Pichler-Strasse 30, 8160 Weiz, Austria 4 Montanuniversität Leoben, Franz Josef Strasse 18, 8700 Leoben, Austria Ring opening metathesis polymerization (ROMP) has become an important tool for the synthesis of highly defined polymers and various polymer architectures. In the present work, the residual double bonds in ROMP derived polymeric materials were exploited for a photoinduced thiol-ene reaction in order to achieve a selective cross-linking of the macromolecules. To demonstrate the versatility of this reaction for the realization of polymeric microstructures, thin films of poly(norbornene dicarboxylic acid, dimethylester) were structured by means of photolithography. Besides the photoinduced thiol-ene reaction, which was investigated by means of FTIR measurements, also the cross-linking of the macromolecules and thus the change in the solubility were assessed by means of sol-gel analysis. Thin films of this polymer were laterally patterned using conventional single photon lithography leading to resolutions in the µm range. Going a step further, this approach can also be used for realizing 3D polynorborne microstructures employing the two photo absorption writing technique. The obtained 3D features have been visualized by scanning electron microscopy and atomic force microscopy, respectively. The accessibility and reactivity of the polynorbornene main chain C = C double bonds in the thiol-ene reaction paves the way towards novel strategies for the realization of polymer 2D and 3D microstructures. 177

180 POS-68, PMP, Wed, 17:45 Raman investigation of tannin foams Maurizio Musso 1, Alexander Petutschnigg 2, Gianluca Tondi 2 1 University of Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg, Austria 2 FHS, University of Applied Sciences, Urstein Süd 1, 5412 Puch/Salzburg, Austria Tannin-based organic foams are new foam materials which are environmentally friendly, resistant to fire and inexpensive, and intended to be used for building insulation, and also as water absorber or shock absorber. These foams can be produced via an acid catalyzed polycondensation reaction between condensed flavonoids and furfuryl alcohol [1-2]. Several studies deal with the mechanism involved in this process [3], but some ambiguities still persist. Raman spectroscopy is an analytical technique suitable for the non-destructive chemical investigation of polymers, allowing to determine the presence of functional groups within a polymer through the interaction of laser light with the vibrational modes of the molecules setting up the sample under investigation [4]. By this spectroscopic technique we have characterized the tannin-based foams and compared their spectral signature with that of tannins, and of polymerized furfuryl alcohol [5]. Similarities and differences to the spectral features of carbonaceous material are discussed. [1] Tondi G., Zhao W., Pizzi A., Du G., Fierro V., Celzard A., Bioresources Technology 100, 5162 (2009) [2] Tondi G., Fierro V., Pizzi A., Celzard A., Carbon 47, 1480 (2009) [3] Gandini A., Polym. Chem. 1, 245 (2010) [4] M.A. Amer, Raman Spectroscopy for Soft Matter Applications, Wiley, Hoboken (2009) [5] S. Bertarione, F. Bonino, F. Cesano, S. Jain, M. Zanetti, D. Scarano, and A. Zecchina, J. Phys. Chem. B 113, (2009) POS-69, PMP, Wed, 17:45 The effect of sacrificial bonds on the mechanical behavior of a single polymer chain- A Monte Carlo study Soran Nabavi 1, Markus Hartmann 1 1 Montanuniversität Leoben, Franz Josef Strasse 18, 8700 Leoben, Austria Understanding the basic building principles of biological materials from a fundamental point of view is a necessary prerequisite for possible transfer of these principles to technology. The byssal thread is an especially fascinating material showing high toughness, stiffness and extensibility. The byssal thread is secreted by marine mussels to adhere to rocky substrates. Being covered with a hard coating providing wear resistance, it shows an extensibility of more than 100 % with the ability of self-healing. Experimental studies on this system suggest that the high extensibility is due to so called sacrificial bonds (SBs). Sacrificial Bonds are weaker than the covalent bonds holding the structure together and they can thermally induced open and close reversibly. The SBs break before the covalent bond rupture, providing hidden length and allowing for efficient energy dissipation. By this effect the toughness of the structure is significantly enhanced. These findings motivate the following simple model. The basic unit is a linear, covalently bonded polymer chain. Some of the monomers (so called sticky sites) can additionally form sacificial bonds. Starting from a collapsed chain cyclic loading experiments were mimicked by determination of load-displacement curves by calculation of the mean force exerted by the chain for several end-to-end distances. The effect of the density and of the arrangement (ordered, random) of sticky sites on the mechanical behavior of the chain was investigated. For sufficiently high sticky site densities a pronounced hysteresis between stretching and relaxing of the chain could be observed. 178

181 Contributors A Abele, Hartmut, , 152 Abermann, Stephan, 121 Adam, Wolfgang, 21, 43 Ahn, Sang Il, 93 Aichmayer, Barbara, 157 Akbarzadeh, Johanna, 121, 154 Akhtar, Nadeem, 144 Akis, Richard, 86 Alberti, Carlos Armando, 165 Alexewicz, Alexander, 95 Alkofer, Reinhard, 46, 48, 49 Al-Saidi, Wissam, 120 Amann, Peter, 118 Amenitsch, Heinz, 87, 97, 99 An der Lan, Lukas, 146 Andersson, Pontus, 151 Andrews, Aaron Maxwell, 92, 95, 160 Anjum, Naveed, 144 Aoki, Nobuyuki, 86 Argentero, Giacomo, 127 Arndt, Markus, 76 Arrigoni, Enrico, 91 ASACUSA Collaboration, The, 40 Atkinson, Paola, 86 Ausserlechner, Simon, 96 Aziz, Kirmanj, 161 B Badurek, Gerald, 52 Balakireva, Irina, 151 Balazs, Peter, 67, 68 Baranov, Mikhail, 118 Barcaro, Giovanni, 124, 170 Bartl, Peter, 146 Bauer, Günther, 155 Baumgartner, Dietmar, 167 Baumgartner, Oskar, 92 Baumgartner, Robert, 69 Belushkin, Maxim, 95 Benedek, Giorgio, 175 Bergauer, Thomas, 56, 57 Berger, Karl, 167 Berger, Thomas, 111, 166 Bergmann, Olaf, 42 Berkebile, Stephen, 129, 130 Bernet, Stefan, 19 Bernt, Ingo, 177 Berrada, Tarik, 76 Bertel, Erminald, 118 Besser, Bruno, 106 Betz, Thomas, 75 Bilski, Pawe l, Blaha, Peter, 157 Blatnik, Matthias, 49 Brandner, Hannes, 96 Brandstätter, Birgit, 144 Briegel, Hans, 21 Brueckl, Hubert, 121 Brunner, Frank, 95 Brunner, Roland, 86, 93 Brunner, Stefan, 59, 148 Buchriegler, Josef, 42, 51, 153 Bücker, Robert, 76 Bucko, Tomas, 120 Bulla, Lukas, 94 Burgstaller, Lukas, 93 Burke, Adam, 86 C Cacho-Nerin, Fernando, 87, 97, 99 Campi, Davide, 175 Capriotti, Mattia, 95 Cargnelli, Michael, 40 Carilli, Jessica, 112 Cervinka, Thomas, 152 Charles, William, 93 Chioncel, Liviu, 91 Choi, Joongil Jake, 126 Chrastina, Daniel, 154 Colavita, Paula, 121 Cordin, Michael, 118 Costacurta, Stefano, 87 Cronenberg, Gunther, 148 Cronin, James, 17 Curceanu, Catalina, 59 D Daghofer, Maria, 100, 101 Daschiel, Ute, 177 Daxner, Mathias, 146 Della Valle, Raphaele, 125 Denifl, Stephan, 79, 81, 146 Denk, Mariella, 168 Denk, Martin, 124, 170 Denk, Richard, 168 Detz, Hermann, 92, 160 Diaz, Ana, 154 Diebold, Ulrike, 118, 126, 127, 172, 176 Diehl, Sebastian, 118 Diermaier, Martin, 40, 41 Dimopoulos, Theodorus, 121 Dingemans, Theo, 173 Ditlbacher, Harald, 77 Djuric, Tatjana, 130 Doblhoff-Dier, Nicolette, 20

182 Dohr, Michael, 96, 173 Doljeschi, Paul, 56, 57 Draxl, Claudia, 119 Duehrssen-Debling, Michael, 54 E Echt, Olof, 146 Eck, Hans, 163 Eckhart, Rene, 177 Egger, David, 120 Eichmann, Gernot, 50 Einkemmer, Lukas, 160 Ellis, Andrew, 146 Ellmeier, Michaela, 145 Erhart, Jacqueline, 149, 150, 152 Ernst, Wolfgang, 75, 78, 80, 81, 123, 175 Ertler, Christian, 90, 91 Eschlböck-Fuchs, Simon, 145 Etzelstorfer, Tanja, 88, 154, 155 F Faccinelli, Martin, 156 Falcaro, Paolo, 87 Fattinger, Michael, 131 Faustini, Marco, 87 Fecht, Hans-Jörg, 98 Federmann, Silke, 40 Feige, Jenny, 41, 42 Ferry, David, 86 Fifield, Keith, 41 Fillunger, Harald, 149 Filter, Hanno, 148 Fischer, Christian, 46 Fischer, Franz, 100 Fischer, Julia, 54 Fisslthaler, Evelin, 123 Flachberger, Helmut, 171 Flaig, Sylvia, 154 Fobes, David, 118 Foffi, Giuseppe, 95 Folk, Reinhard, 106 Forchel, Alfred, 160 Forró, László, 95 Forstner, Oliver, 51, 151 Fortunelli, Alessandro, 124, 170, 171 Franchini, Cesare, 118 Frank, Matthias, 65, 66 Frank, Sebastian, 58 Frankenberger, Annekathrin, 56, 57 Franosch, Thomas, 95 Friedl, Markus, 56, 57 Frisén, Jonas, 42 Fritz-Popovski, Gerhard, 87, 157 Fromherz, Thomas, 93 Frühwirth, Edwin, 55 Frühwirth, Rudolf, 57, 58 Fuchsbichler, Bernd, 98 G Gajic, Rados, 169 Gall, Johannes, 129 Gammer, Christoph, 97 Gamper, Bettina, 82 Gansch, Roman, 92 Ganser, Christian, 167, 169 Garay Walls, Francisca, 54 Geerts, Yves, 96, 125, 173 Geist, David, 97 Gerhold, Stefan, 176 Gerstmann, Johann, 30 Gfall, Immanuel, 56, 57 Gießibl, Franz, 18 Gierschner, Johannes, 173 Giordani, Silvia, 121 Glattauer, Robin, 58 Gleichweit, Christoph, 130, 168 Glushko, Oleksandr, 93 Gmachl, Claire, 93 Göcke, Tobias, 46 Golob, Andreas, 105 Golser, Robin, 41, 42, 51, 151, 153 Gösselsberger, Christoph, 52 Gottfried, Strasser, 93 Goulart, Marcelo, 79, 146 G lowacki, Eric, 173 Graber, Gerhard, 71 Granitzer, Petra, 155 Griesser, Thomas, 177 Grimm, Matthias, 95 Grobosch, Mandy, 124 Grogger, Werner, 123 Groiss, Heiko, 155 Grosso, David, 87 Gruber, Christian, 77 Gruber, Lukas, 59, 148 Gruber, Thomas, 75 Gschliesser, David, 79, 146 Guedes Matias, Carolina, 146 Gusenleitner, Sina, 130 Gutberlet, Thomas, 113 H Hadley, Peter, 156 Haiden, Philip, 149 Hajek, Michael, 111, 165, 166 HAK/HAS, Mistelbach, 31 Hammer, René, 91 Hanstorp, Dag, 151 Harrington Jr, Robert Duane, 54 Hartmann, Markus, 100, 178 Hasewend, Matthias, 80 Haslinger, Michael,

183 Hauser, Andreas, 75, 81 Hebenstreit, Florian, 46 Heiss, Wolfgang, 87, 88 Heitz, Johannes, 145 Herbst, Tina K., 47 Hieckel, Marcel, 118 Hinterreiter, Andreas, 145 Hirschl, Robin, 29 Hirschmugl-Gaisch, Sabine, 163 Hirtl, Albert, 148 Hlawacek, Gregor, 123 Hofer, Ferdinand, 77 Höfling, Sven, 160 Hofstaetter, Michael, 172 Hofstätter, Christina, 111, 166 Hohage, Michael, 129, 168 Hohenau, Andreas, 77, 80 Hohenester, Ulrich, 77 Hohl, Roland, 111 Höldrich, Robert, 65 Holec, David, 100 Holy, Vaclav, 88, 155 Hopfer, Markus, 49 Hörselmann, Ingo, 124 Horvath, Miklos, 149 Hrauda, Nina, 155 Huber, Harald, 152 Huber, Markus, 47, 48 Huber, Norbert, 145 Huesing, Nicola, 154 Hühnermann, Harry, 144 Humer, Markus, 93 I Innocenzi, Plinio, 87 Irimia-Vladu, Mihai, 173 Irmler, Christian, 56, 57 Isella, Giovanni, 154 Isepp, Katharina, 150 Ishiwatari, Tomoichi, 40 J Janits, Beatrix, 164 Jankovec, Martin, 148 Jaques, Vincent, 154 Jeney, Sylvia, 95 Jenke, Tobias, 39, 148 Jericha, Erwin, 52 Jerrar, Abdellatif, 177 Jesacher, Alexander, 19 Jestin, Jacques, 113 Jovanovic, Djordje, 169 Jungnikl, Karin, 99 Jussel, Patrick, 44 K Kahn, Saranjam, Kalchmair, Stefan, 92 Kalliokoski, M., 162 Kaltenbrunner, Martin, 90 Kamencek, Thomas, 61 Karnthaler, Peter, 97 Kaseß, Christian, 70 Kautsch, Andreas, 80 Kazakov, Georgy, 147 Keplinger, Mario, 88 Kern, Wolfgang, 177 Kerscher, Tobias, 156 Khinast, Johannes, 111 Kiener, Daniel, 19 Kirchengast, Gottfried, 162 Kirchner, Helmut, 158 Kirnstötter, Stefan, 156 Klima, Stefan, 169 Klopf, Michael, 150 Kneringer, Emmerich, 45 Knoll, Peter, 148, 157, 161 Knupfer, Martin, 124 Koch, Markus, 78, 80, 81, 123 Koch, Reinhold, 131 Kohlfürst, Christian, 46 Kolíbal, Miroslav, 127 Koller, Georg, 125, 129, 176, 177 Koller, Stefan, 98 Kolmhofer, Philipp, 145 Kondratenko, Sergey, 126 Konrad, Gertrud, 52, 149, 150, 152 Körner, Christine, 111 Korschinek, Gunther, 41 Kosina, Hans, 92 Kourtis, Stefanos, 100 Kovac, Pavol, 94 Kovalenko, Maksym, 88 Kozyrev, Yury, 126 Kraft, Jochen, 134 Krämer, Sebastian, 146 Kraml, Armand, 107 Kraml, Sabine, 58 Kranzelbinder, Heinrich, 162 Krätschmer, Ilse, 44 Kratzer, Markus, 126, 169, 171 Kraus, Patrick, 175 Krause, Reinhard, 162 Kreiml, Patrice, 169 Krenn, Heinz, 94, 108 Krenn, Joachim, 77, 80 Krenn, Kurt, 157 Kreuzer, Wolfgang, Kriegner, Dominik, 88 Krois, Günter, 78 Kronland-Martinet, Richard, 68 Kuetgens, Ulrich, 152 Kufstein, Stadttheater, 22

184 Kuhness, David, 124, 170 Kumar, Sanjeev, 101 Kusar, Primoz, 77 Kutschera, Walter, 42 L Laback, Bernhard, Lackner, Florian, 78 Laggner, Peter, 99 Lammegger, Roland, 145 LEANNIS network, The, 39 Lechner, Rainer, 87 Leidl, Roman, 167 Leidlmair, Christian, 146 Leising, Günther, 30 Leitner, Martin, 156, 162 Leitner, Matthias, 159 Lettenbichler, Jakob, 57 Li, Chenghao, 160 Liebl, Jakob, 42 Lindahl, Anton, 151 Löffler, Andreas, 160 Lonez, Caroline, 113 Lorbek, Stefan, 96 Lucha, Wolfgang, 151 Luckabauer, Martin, 98 Lüftner, Daniel, 125 Lukas, Wolfgang, 45 Lukesch, Walter, 174 Lutzer, Bernhard, 54 M Maaß, Sebastian, 152 Maas, Axel, 47 Mader, Valentin, 48 Magnes, Werner, 145 Mahmoudi, Nazila, 58 Mai, Patrick, 160 Mair, Klaus, 42, 51 Majdak, Piotr, 69, 70 Malbrunot, Chloé, 40 Malfatti, Luca, 87 Mandl, Bernhard, 88 Mao, Zhiqiang, 118 Marmiroli, Benedetta, 87, 97, 99 Marton, Johann, 39, 40, 59, 148 Martschini, Martin, 42, 51, 151 Massiczek, Oswald, 40, 41 Matias, Carolina, 79 Matkovic, Aleksandar, 169 Matthiä, Daniel, 166 Mauracher, Andreas, 146 Mayrhofer, Paul, 100 Mayrhofer-Reinhartshuber, Michael, 175 Mazuheli, Stefan, 61 Meisels, Ronald, 86, Melikhov, Dimitri, 151 Melisek, Tibor, 94 Mendoza, Benjamin Levy, 165 Menezes, José, 111 Menzel, Alexander, 118 Merchel, Silke, 41 Mercurio, Giuseppe, 20 Messing, Maria, 88 Meunier, Sabine, 68 Michlmayer, Leonard, 42 Mihocic, Michael, 70 Miletzky, Albrecht, 170 Milko, Matus, 119 Mirkowska, Monika, 171 Mitaroff, Winfried, 58 Mittendorfer, Florian, 118, 128 Mitter, Mario, 48, 49 Mittermair, Robert, 168 Mor, Flavio, 95 Morak, Roland Johann, 157 Morales, Puerto, 155 Moser, Armin, 125, 173 Moser, Martin, 152 Muccioli, Luca, 162 Mülleder, Thomas, 61 Müllegger, Stefan, 131 Müller, Mario, 61 Müller, Stefan, 156 Murer, Gerhard, 135 Musso, Maurizio, 157, 161, 178 N Nabavi, Soran, 178 Nadler, Moritz, 57 Necciari, Thibaud, 68 Negreiros, Fabio, 124, 170 Netzer, Falko, 124, 130, 170, 171 Neuhold, Alfred, 96, 173 Neuschitzer, Markus, 96, 173 Niedermayr, Michael, 147 Nikbakhti, Maryam, 167 Novotny, Zbynek, 127 O Oberauer, Christoph, 161 Obermüller, Thomas, 171 Ochiai, Yuichi, 86 Ostermann, Laurin, 78 Ostler, Markus, 129, 176 Oswald, Josef, 158 P Paasch, Gernot, 124 Pabisch, Silvia, 158, 160 Pabst, Georg, 113 Pacheco, Manuel, 159

185 Paris, Oskar, 87, 100, 157, 160 Parkinson, Gareth, 127, 172 Parlar, Anil, 95 Parth, Dieter, 31 Parz, Peter, 98, 159 Pavelec, Jiří, 172 Pavitschitz, Andreas, 169, 172 Pawlowski, Jan Martin, 47 Pedarnig, Johannes, 145 Peić, Antun, 121 PERC Collaboration, The, 52 Perez, Javier, 97 Perova, Tatiana, 121 Peterlik, Herwig, 121, 154, 158, 160 Petutschnigg, Alexander, 178 Pichler, Alexander, 173 Pichler, Franz, 108 Pillmayr, Norbert, 28, 33 Pirró, David, 65 Plagg, Stefan, 71 Pobitzer, Martin, 71 Podloucky, Raimund, 118, 128, 156 Poelsema, Bene, 123 Pogany, Dionyz, 95 Pohl, Wilfried, 32 Pollinger, Andreas, 145 Pölt, Peter, 122, 155 Portolan, Stefano, 160 Posch, Thomas, 29 Postler, Johannes, 79, 146 Potocar, Thomas, 152 Pototschnig, Johann, 81 Pottlacher, Gernot, 161 Pötz, Walter, Prehal, Christian, 126 Priller, Alfred, 42, 51, 153 Probst, Michael, 146 Prügger, B., 162 Puchalska, Monika, 166 Puchegger, Stephan, 158, 160 Puff, Werner, 98, 159 Punz, Manuel, 170 Puschnig, Peter, 119, 125, 129 Puschnigg, Benjamin, 81, 146 Putsche, Bernhard, 173 Q Queteschiner, Daniel, 129, 168 R Radinger, Gregor, 32 Radulescu, Aurel, 113 Rahbaran, Babak, 153 Rajagopalan, Shibi, 58 Ralevic, Uros, 169 Rammerstorfer, Franz, 100 Ramsey, Michael, 125, 129, 130, 176 Rappolt, Michael, 99 Rashidi, Mohammad, 131 Rastelli, Armando, 86 Ratschek, Martin, 80, 81 Rechberger, Veronika, 163 Redinger, Josef, 118, 128 Reichel, Erich, 163 Reingruber, Herbert, 122 Reininger, Peter, 92 Reinisch, Eva, 129, 176 Reissner, Michael, 94, 155 Reitberger, Klaus, 22 Reiter, Wolfgang, 104 Reitz, Günther, 111, 166 Rennhofer, Harald, 160 Rennhofer, Marcus, 121, 167 Rentenberger, Christian, 97 Resel, Roland, 96, 125, 130, 173 Ritsch, Elmar, 54 Ritsch, Helmut, 78, 146 Ritsch-Marte, Monika, 19 Rohlén, Johan, 151 Rohm, Sebastian, 174 Roider, Clemens, 19 Romero Vidal, Antonio, 59 Roscioni, Otello, 162 Rössler, Roman, 145 Rubezhanska, Maria, 126 Rudamas, Carlos, 159, 165 Rugel, Georg, 41 Ruiz, Victor, 120 Rumpf, Klemens, 155 Ruysschaert, Jean-Marie, 113 S Sacher, Stefan, 111 Sachslehner, Franz, 104 Salzburger, Andreas, 45, 54 Salzmann, Ingo, 96, 125 Sanchis-Alepuz, Helios, 49 Sandoghdar, Vahid, 24 Sartori, Barbara, 87, 97, 99 Sassermann, Mathias, 160 Sauerzopf, Clemens, 40 Savel, Sophie, 68 Schaefer, Bernd-Jochen, 47, 49 Schaelicke, Andreas, 54 Schaff, Jean-Francois, 76 Schaffer, Mathias, 33 Schafler, Erhard, 121 Scheibelhofer, Otto, 111 Scheier, Paul, 79, 81, 146 Scheinert, Susanne, 124 Schennach, Robert, 119, 121, 167, 169, 174, 177 Scherwitzl, Boris,

186 Schiefler, Gustav, 154 Schittelkopf, Eduard, 163 Schlosser, Viktor, 167 Schmalzer, Nadine, 61 Schmid, Michael, 118, 126, 127, 172, 176 Schmidt, Edith, 42 Schmidt, Franz, 77 Schmidt, Günther, 157 Schmidt, Oliver, 86 Schmidt, Volker, 177 Schmied, Franz, 121 Schmiedmayer, Jörg, 76 Schmitz, David, 75 Schmon, Alexander, 161 Schneider, Christian, 160 Schnell, Melanie, 75 Schöbel, Harald, 146 Schöfbeck, Robert, 43 Schreitl, Matthias, 147 Schrenk, Werner, 92, 93 Schumm, Thorsten, 76, 147 Schustereder, Werner, 156 Schwabegger, Günter, 173 Schwanda, Christoph, 45 Schwarz, Benedikt, 92 Schwarz, Karlheinz, 157 Schwarz, Stefan, 149 Schwarzer, Clemens, 93 Sclafani, Michele, 76 Scordo, Alessandro, 59 Sementa, Luca, 124, 170 Sereni, Paolo, 157, 161 Seyller, Thomas, 129 Sferrazza, Michele, 96, 125, 173 Shen, Quan, 96 Sherwood, Peter, 54 Shubert, Alvin, 75 Shyjumon, Ibrahimkutty, 99 SIDDHARTA Collaboration, The, 39 Siddiqui, Imran, 82 Siegel, Stefan, 160 Siess, Josef, 135 Sigg, Hans-Christian, 154 Šikola, Tomáš, 127 Simbrunner, Clemens, 173 Sitter, Helmut, 173 Smiljic, Dusko, 56, 57 Sontacchi, Alois, 65 Sorta, Stefan, 94 Spalding, Kirsty, 42 Spolenak, Ralph, 154 Sprengel, Wolfgang, 98, 159 Stangl, Julian, 88, 154, 155 Stanohevic, Zlatan, 92 Steier, Peter, 42, 51, 112, 153 Steinacker, Harold, Steinhauser, Georg, 147 Steinmüller-Nethl, Doris, 134 Sterba, Johannes, 51 Steurer, Wolfram, 171 Stickler, Benjamin, 91 Stöger, Bernhard, 118 Stolterfoht, Martin, 162 Strasser, Gottfried, 92, 95, 160 Stricker, Stefan, 46 Stuetz, Engelbert, 164 Süess, Martin, 154 Sun, Lidong, 129, 168 Supancic, Peter, 172 Surnev, Svetlozar, 124, 170, 171 Suzuki, Ken, 59, 148 Swain, John, 17 Sytnyk, Mykhailo, 88 T Tamtögl, Anton, 175 Tanzer, Katrin, 81 Teichert, Christian, 96, 126, 167, 169, 171, 172, 177 Teischinger, Florian, 53 Thalhammer, Gregor, 19 Thórhallsdóttir, Ester, 162 Thorne, Felicitas, 45 Tinguley, Jean-Claude, 80 Tkatchenko, Alexandre, 120 Todt, Melanie, 100 Tondi, Gianluca, 178 Topolovec, Stefan, 94 Treberer-Treberspurg, Wolfgang, 56 Tributsch, Helmut, 28 Tritthart, Stefanie Anna, 164 Trotta, Rinaldo, 86 Tschürtz, Sabine, 162 Tümbek, Levent, 130, 168, 175 U Ules, Thomas, 125, 129, 176 Usanova, Anna, 44, 54 V Valentan, Manfred, 56, 57 Vandenbranden, Michel, 113 van den Brink, Jeroen, 100, 101 Van Frank, Sandrine, 76 van Gastel, Raoul, 123 Van Opdenbosch, Daniel, 157 Vasic, Borislav, 169 Vazquez Doce, Oton, 59 Veligura, Vasilisa, 123 Venderbos, Jörn, 100, 101 Vieider, Manuel, 162 Vizcaino, Violaine, 81, 146

187 Volgger, Stefan, 161 Volk, Alexander, 123 von Smekal, Lorenz, 47 Vörös, Zoltán, 160 W Wagner, Jochen, 167 Wagner, Margareta, 124, 130, 170 Wagner, Thorsten, 129 Wallner, Anton, 41, 42 Waltenberger, Wolfgang, 43 Wang, Xiangzun, 53, 149, 152 Wang, Zhiming, 118, 127, 176 Wankhammer, Alexander, 65 Waubke, Holger, 67 Weber, Frederik, 177 Weber, Hansjörg, 170 Weihs, Gregor, 160 Weihs, Philipp, 167 Weinert, Michael, 128 Weiss, Ingrid, 158 Werzer, Oliver, 96 Widmann, Eberhard, 40, 41 Wieninger, Thomas, 51 Wild, Eva-Maria, 42 Williams, Richard, 46, 49 Windholz, Laurentius, 82, 144, 145 Windisch, Andreas, 48 Winkler, Adolf, 130, 168, Winkler, Georg, 147 Winkler, Stephan, 41, 112, 153 Wolfberger, Archim, 177 Wollboldt, Petra, 170 Wunderlich, Rainer, 98 Wünschek, Barbara, 40 Würschum, Roland, 94, 98 Zojer, Egbert, 96, 120, 162 Zojer, Karin, 130, 168 Zollfrank, Cordt, 157 Zotter, Franz, 66 Zöttl, Samuel, 146 Zoubi, Hashem, 78 Y Yarema, Maksym, 87, 88 Ystad, Sølvi, 68 Z Zaheer, Uddin, 82 Zallo, Eugenio, 86 Zandvliet, Harold, 123 Zankel, Armin, 122 Zannoni, Claudio, 162 Zawisky, Michael, 152 Zechner, Andrea, 166 Zederbauer, Tobias, 92, 160 Zeppenfeld, Peter, 129, 168 Zhang, Jianjun, 155 Zharnikov, Michael, 162 Ziegelwanger, Harald, 69 Zimmerling, Martin, 135 Zmeskal, Johann, 40,

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