KATRIN: hunting neutrino masses

Transkript

1 KATRIN: hunting neutrino masses ν s in astroparticle physics KATRIN -principle - main components - sensitivity Outlook

2 motivation: ν s in astroparticle physics cosmic architects: role of relic ν s as hot dark matter? large scale structures: free streaming of ν s on Gpc scales cosmology m ν = 0 ev m ν = 1 ev structure of the universe (Millenium Simulation) m ν = 7 ev m ν = 4 ev

3 motivation: ν s in astroparticle physics cosmic architects: role of ν s as hot dark matter? microscopic keys: origin of the ν-mass? cosmology particle physics mass [GeV] fermions bosons structure of the universe (Millenium Simulation) neutrinos massless bosons

4 motivation: ν s in astroparticle physics cosmic architects: role of relic ν s as hot dark matter? microscopic keys: origin of the ν-mass? Ω ν h 2 = Σ m ν / 92 ev tritium experiments cosmolog. relevant parameters dark energy dark matter baryons ν µ stars & gas ν e structure of the universe (Millenium Simulation)

5 motivation: ν s in astroparticle physics cosmic architects: role of relic ν s as hot dark matter? microscopic keys: origin of the ν-mass? m ν could fix dark energy equation of state w scale parameter a(t) deceleration acceleration big rip vacuumenergy big crunch w = P / ρc 2 dark energy dark matter baryons stars & gas structure of the universe (Millenium Simulation) today time t Ω

6 motivation: ν s in astroparticle physics microskopic keys: origin of the ν-mass? m(ν) most important parameter for ν-theory! particle physics quasi-degenerated scenario quasi-degenerated mass models see-saw models: Typ I-II-III? extra dimensions? triplett-higgs? family symmetry? hierarchical scenario hierarchical mass models

7 neutrino mass: status and perspectives kinematics of ß-decay absolute ν e -mass: m ν model-independent status: m ν < 2.3 ev potential: m ν = 200 mev KATRIN (MARE-II) search for 0νßß eff. Majorana mass m ßß model-dependent (CP-phases) status: m ßß < 0.35 ev, evidence? potential: m ßß = mev GERDA, EXO, CUORE neutrino masses experimental techniques: status & potential cosmology sum Σm i, HDM Ω ν model-dependent (multi-parameter fits) status: Σm i < 1 ev [Hannestad et al., arxiv: v2] potential: Σm i = mev Planck, LSST, weak lensing

8 ß-decay: Fermi s theory & ν-mass a model-independent measurement of m(ν e ) based on kinematics & energy conservation dγi de = C p ( E + m which isotope? e ) ( E E) ( E E) m F ( E, Z ) θ ( E i 0 i 3 H: super-allowed (ν mass) ( ν e ) = ei mi i= 1 m U incoherent sum E m ) Fermi s theory E 0 t 1/ kev 12.3 y

9 history of tritium ß-decay experiments experimental results for m 2 ν < 2.3 ev < 2.3 ev

10 MAC-E filter principle MAC Magnetic Adiabatic Guiding adiabatic guiding of electrons along magnetic field lines inhomogenous B-field: superconducting solenoids B max = 3 6 T B min < 1 mt solid angle dω ~ 2π r F = μ = r r r B + q E / B = const. ( μ ) E r T 2 source s.c. solenoid s.c. solenoid detector adiabatic transformation E E

11 MAC-E filter principle E Filter Electrostatic filter energy analysis by an electrostatic retarding field variable E-field: inner electrodes U 0 = kv integral transmission for E > U 0 high pass filter E Feld B-Feld T 2 source s.c. solenoid HV electrodes s.c. solenoid detector conversion retarding adiabatic transformation E E

12 KATRIN a MAC-E filter system tritium source adiabatic particle transport over 70 m spectrometer detector B-field [T] ultraluminous molecular windowless gaseous tritium source ß-spectroscopy with ΔE =0.93 ev 1: distance from analysing plane [m]

13 KATRIN windowless gaseous source tritium source 16 m long complex cryostat: -12 cryogenic circuits - 6 cryogenic fluids - instrumentation: ~500 sensors for temperature (4 600 K), B-field, pressure, gas flow, liquid levels,

14 KATRIN windowless gaseous source tritium source WGTS design value precision luminosity Bq injection rate mol/s ± 0.1 % column density ρd mol/cm 2 ± 0.1 % tritium purity > 95% magnetic field 3.6 T ± 2% WGTS demonstrator (12m) currently being assembled delivery to TLK in June 2009 key technological challenge: precise cooling of beam tube temperature stabilsation of beam tube of K

15 KATRIN tritium infrastructure 27 pumps, 109 valves 62 sensors, 6 buffer vessels 2 permeators Tritium troughput/year equivalent to ITER CMS-R 5% 95% DPS1-R WGTS DPS1-F inner loop control system T 2 injection DPS2-F 95% 5% CPS batch mode, 60 days (<1 Ci) 1% outer loop T 2 preparation isotope separation 1% outer loop T 2 retentionsystem

16 KATRIN tritium infrastructure set-up of inner loop system in progress

17 KATRIN tritium retention the tritium flow out of the WGTS has to be reduced by factor ~10 14 tritium bearing components tritium free WGTS DPS2-F CPS spectrometers p [10-3 mbar] differential cryogenic pumping p(t 2 ) < mbar injection injection rate = 1.8 mbar l / s R>10 7 R> mbar l /s mbar l /s

18 differential pumping section DPS2-F active tritium pumping with 4 TMP s 6.2 m DPS2-F TMP #4 cryostat ß s TMP #1 beamtube & magnets pump port

19 cryogenic pumping section CPS CPS UHV pumpingduct DN100 77K argon frost pump T = K 77K cold valve DN 150 RT objective: reduction of T 2 -flux by factor 10 7 : 10-7 mbar l /s mbar l /s method: cryo-sorption on condensing Ar-frost T 2 -rate: <1 Ci T 2 in 60 days = 1 KATRIN run (regeneration with warm He-gas) presently being manufactured by ASG

20 cryogenic pumping section CPS CPS RT UHV pumpingduct DN100 77K cold valve DN K argon frost pump T = K

21 electrostatic spectrometers UHV p < mbar pre-filter fixed retarding potential U 0 = kv ΔE ~ 100 ev - filter out all ß-decay electrons without m(ν)-info - reduce background from ionising collisions no info on m(ν) precision filter - scanning variable retarding potential U 0 = kv ΔE ~ 0.93 ev (100% transmission) tandem design: pre-filter & energy analysis

22 pre-spectrometer UHV UHV p < mbar successful verification of UHV concept SAES getters

23 pre-spectrometer: electromagnetic tests optimisation of electromagnetic design - minimisation of Penning traps - background reduction techniques (dipole fields) - study of field emission diameter = 1.7m length = 3.4m dipole fields Si-PIN e-gun

24 main spectrometer: world s largest UHV recipient Helmholtzcoils UHV : p < mbar! Helmholtz coils vessel on HV dimensions: diameter: 10 m length: 23.3 m surface: 690 m 2 volume: 1240 m 3 24 G. Drexlin G. KECTA IK & EKP Dec , 2008

25 main spectrometer: world s largest UHV recipient KATRIN Volume pressure method spectrometer 1250 m mbar turbomolecular pumps / nonevaporable getters LHC accelerator LHC Volume pressure method storage ring 154 m mbar cryogenic insulation 640 m mbar cryocondensation on beam screen/magnet bore (1.9K) cryocondensation on magnet cold mass KATRIN spectrometer VIRGO antennae LIGO Volume pressure method 2x4km arms 8000 m 3 ~10-8 mbar ion pumps & cold traps VIRGO Volume pressure method 2x3km arms 6800 m 3 <10-9 mbar titanium & ion pumps

26 main spectrometer: pre-acceptance tests August TMP (WMAG2800) p < 6 x 10-8 mbar initial integral He-leak test at MAN-DWE

27 main spectrometer: transport 250 km Donau

28 main spectrometer: transport Donau start: Oct 2006 Deggendorf MAN-DWE Danube manufacture hall

29 main spectrometer: transport Jochenstein lock

30 main spectrometer: transport Donau

31 the final 7km: passing Leopoldshafen November 25, 2006: after an 8800 km sea-going voayge the main Spectrometer was manoeuvred by an SPMT over 7km to the final destination at the KATRIN experimental halls ( visitors) arrival at Leimersheim ferry & reloading onto SPMT with heavy-duty crane KATRIN KATRIN 7 km In pictures: photos of the year 2006 SPMT river Rhine

32 the final 7m, initial out-baking & UHV July 2007: initial UHV tests of vessel after out-baking with 6 TMPs steam blasting outgassing rate [ T = 20 C ] mbar l / cm 2 s p = mbar H 2 0 H 2 November 29, 2006 temperature distribution vessel at T = 350 C

33 the final 7m, initial out-baking & UHV KATRIN vacuum group KIT board of directors November 29, 2006 temperature distribution vessel at T = 350 C

34 main spectrometer: inner electrodes spectrometer inner surface: covered by a massless inner wire-based electrode (2 layers) - fine forming of retarding potential - suppression of cosmic muon induced electron background 248 modules: > wires 100µm precision for M10 bolts

35 KATRIN at Tritium Laboratory Karlsruhe all new experimental halls of KATRIN are completed & operational. KATRIN experiment at Tritiumlaboratory Karlsruhe (TLK)

36 KATRIN at Tritium Laboratory Karlsruhe TLK new non-magnetic KATRIN halls all new experimental halls of KATRIN are completed & operational. KATRIN experiment at Tritiumlaboratory Karlsruhe (TLK) tomorrow: visit of experiment

37 KATRIN ß-spectrum & sensitivity statistical and systematic errors will contribute equally to sensitivity MC spectrum - 1 KATRIN fb-year sensitivity - 3 KATRIN fb-yeats sensitivity/discovery potential [σ] sensitivity (90% CL) m(ν) < 200 mev reference set-up ν-mass m ν [ev]

38 KATRIN impact on astroparticle physics cosmic architects: fix relic-ν role as hot dark matter microscopic keys: fix generic neutrino mass pattern tritium ß-decay dark energy dark matter baryons KATRIN stars gas ν oscillations KATRIN : a key experiment for astroparticle physics

39 KATRIN Collaboration uniting the world-wide expertise in tritium ß-decay experiments: ~140 Collaboration members (12 institutions from D, USA, GB, CZ, Russia) ~ 60% from KIT pool of expertise (IK, EKP, ITP/TLK, IPE) 2012: begin of T 2 measurements 2008

40 vision 2058: relic ν background novel idea: mapping the universe at t = 100 µs after the Big Bang: capture of relic neutrinos on a ß-unstabile isotope ( 3 H): ν s from the Big Bang (t = 0.1 s) CNB ν e + 3 H 3 He + e - no threshold! ν µ relic neutrinos ν e solar neutrinos SN1987a geo neutrinos reactor neutrinos relic SN neutrinos cosmic neutrinos atmospheric neutrinos ν-energy [ev] cosmic microwave background (t = a)

41 vision 2058: relic ν background & KN100 novel idea: mapping the universe at t = 100 µs after the Big Bang: capture of relic neutrinos on a ß-unstabile isotope ( 3 H): ν e + 3 H 3 He + e - no threshold! i-paper relic neutrinos solar neutrinos cosmic neutrinos SN1987a geo neutrinos reactor neutrinos relic SN neutrinos atmospheric neutrinos 2058: Karlsruher Nuclide Chart will turn 100 ν-energy [ev]