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Results of NEMO 3 and status of SuperNEMO

Results of NEMO 3 and status of SuperNEMO. Ladislav VÁLA on behalf of the NEMO 3 and SuperNEMO collaborations Institute of Experimental and Applied Physics Czech Technical University in Prague. NOW 2008, 6 – 13 September 2008, Conca Specchiulla, Italy.

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Results of NEMO 3 and status of SuperNEMO

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  1. Results of NEMO 3 and status of SuperNEMO Ladislav VÁLA on behalf of the NEMO 3 and SuperNEMO collaborations Institute of Experimental and Applied Physics Czech Technical University in Prague NOW 2008, 6 – 13 September 2008, Conca Specchiulla, Italy

  2. Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 Outline • Brief introduction – bb decay • NEMO 3 – description and results • SuperNEMO – current status • Summary

  3. Two-neutrino bb decay (2nbb): (A,Z) →(A,Z+2) + 2 e- + 2 ne 0+ 1+ 100Tc 100Mo 41+ 01+ 21+ 22+ 0+ 100Ru 3034 keV Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 Double beta decay In even-even nuclei where single b- decay is highly suppressed or forbidden but b-b- decay is possible, e.g. 48Ca, 76Ge, 82Se, 96Zr, 100Mo,116Cd, 130Te, 136Xe, 150Nd,… G0n = (T1/2)-1 = G0n(Qbb5,Z)|M0n|2mn2 G0n – phase space factor M – nuclear matrix element mn = | Sj |Uej|2 eiaj mj | – effective neutrino mass Energy sum of the electrons Neutrinoless bb decay (0nbb): (A,Z) →(A,Z+2) + 2 e- G2n = (T1/2)-1 = G2n(Qbb11,Z)|M2n|2 G2n – phase space factor M – nuclear matrix element Beyond SM DL = 2, Majorana neutrinos nn with mass > 0 Can be due to: light neutrino exchange mn, right-handed currents, Majorana emission, SUSY particle exchange

  4. Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 NEMO experimental approach Calorimetry plus tracking Detection of both electrons:reject unknown nuclear gamma lines Three kinematic observables:study underlying physics mechanism (i) individual electron energies (ii) angular correlation (iii) energy sum Sources separated from the detector:measure T1/2 for several isotopes Background rejection through particle identification:e–, e+, g, a particles Unique and complementary

  5. 20 sectors 3 m 6 m B (25 G) 4 m 6 m Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 NEMO 3 detector NEMO = Neutrino Ettore Majorana Observatory Detector located in the LSM Modane underground laboratory, France (4800 m.w.e.) Source: 10 kg of  isotopes, cylindrical, S = 20 m2, foils ~ 60mg/cm2 Tracking detector: drift wire chamber operating in Geiger mode (6180 cells) gas = 94% He + 4% ethyl alcohol + 1% Ar + 0.1% H2O Calorimeter: 1940 plastic scintillators coupled to low radioactivity PMTs Magnetic field: 25 Gauss Gamma shield: pure iron (18 cm layer) Neutron shield: borated water (ext. wall, 30 cm layer) & wood (top and bottom, 40 cm layer) Surrounded by an anti-radon tent supplied with Rn-free air from an anti-radon factory Modane identification of e–, e+, g and a-particles

  6. 100Mo6.914 kg Qbb= 3034 keV & 82Se0.932 kg Qbb = 2995 keV 0nbb decay search Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 NEMO 3 sources 116Cd405 g Qbb = 2805 keV 96Zr 9.4 g Qbb= 3350 keV 150Nd 37.0 g Qbb = 3367 keV 48Ca 7.0 g Qbb = 4272 keV 130Te454 g Qbb = 2529 keV natTe491 g Cu621 g 2nbb decay measurement External background measurement All sources produced by centrifugation in Russia

  7. Run Number: 2040 Event Number: 9732 Date: 2003-03-20 Vertex of the e-e- emission 100Mo foils Scintillator + PMT Vertex of the e-e- emission Deposited energy: E1 + E2= 2088 keV Internal hypothesis: (Dt)mes – (Dt)theo = 0.22 ns Common vertex: (D vertex) = 2.1 mm (D vertex)// = 5.7 mm Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 bb event reconstruction Transverse view Longitudinal view • 2 tracks with charge < 0 • 2 PMTs, each > 200 keV • PMT-Track association • Common vertex • Internal hypothesis TOF (external event rejection) • No other isolated PMT (g rejection) • No delayed a track (214Bi rejection) Criteria to select bb events:

  8. Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 Results for 2nbb of 130Te Energy sum of the electrons Energy sum of the electrons NEMO-3 NEMO-3 109 events 454 g 534 days S/B = 0.25 S + B = 607 events background subtracted Preliminary result: 130Te:T1/2 = [ 7.6 ± 1.5 (stat) ± 0.8 (syst) ]  1020 y

  9. Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 New results for 48Ca High bkg here due to contamination with 90Sr Energy sum of the electrons Angular distribution NEMO-3 NEMO-3 Cut at 0 Cut at 1.5 MeV 133 events 7g 948 days S/B = 6.76 E1 + E2 (MeV) Preliminary results: T1/2 (2) = [4.4 +0.5-0.4 (stat) ± 0.4 (syst)] × 1019 y T1/2 (0) > 1.3 × 1022 y (90% C.L.)m < 29.6 eV(90% C.L.), eff. 22% NME: E. Caurrier et al., Phys. Rev. Lett. 100 (2008) 052503.

  10. Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 New results for 96Zr Angular distribution Energy sum of the electrons NEMO-3 NEMO-3 9.4 g 925 days S/B = 1 Preliminary results: T1/2 (2) = [2.3 ± 0.2(stat) ± 0.3 (syst)] × 1019 y T1/2 (0) > 8.6 × 1022 y(90% C.L.)m < (7.4 – 20.1) eV[1–3] [1] M.Kortelainen and J.Suhonen, Phys.Rev. C 75 (2007) 051303(R). [2] M.Kortelainen and J.Suhonen, Phys.Rev. C 76 (2007) 024315. [3] F.Šimkovic et al., Phys.Rev. C 77 (2008) 045503. NME:

  11. Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 New results for 2nbb of 150Nd Energy sum of the electrons Angular distribution Preliminary result: 150Nd:T1/2 = [ 7.20 +0.25-0.22 (stat) ± 0.73 (syst) ]  1018 y

  12. 150Nd 0nbb MC (T1/2 = 1.45×1022 y) radioactive bkg MC 2nbbbkg + radioactive bkg MC Above 2.5 MeV 28.6 ± 2.7 events expected from background 29 events observed Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 0nbb results for 150Nd Light neutrino exchange: LEP CLs statistical method above 2.5 MeV Detection efficiency: 19% NME: V.A. Rodin et al., Nucl. Phys. A 766 (2006) 107. Previous result: T1/2 > 1.7 × 1021 y (90% CL) A.A. Klimenko et al., Nucl. Instr. Meth. B 17 (1986) 445. Right-handed currents: Emission of Majoron (M1): T1/2 (0nbb) > 1.45 × 1022 y (90% CL) m < 3.7 – 5.1 eV T1/2 (0nbb) > 1.27 × 1022 y (90% CL) T1/2 (0nbb) > 1.55 × 1021 y (90% CL)

  13. Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 Results for 100Mo and 82Se 693 days of data, Phase I + Phase II (data until spring 2006) NEMO-3 NEMO-3 82Se 100Mo T1/2 (2nbb) = [ 7.11 ± 0.02 (stat) ± 0.54 (syst) ]  1018 y (Phys. Rev. Lett. 95 (2005) 182302) T1/2 (0nbb) > 5.8 × 1023 y(90% CL) mn < (0.8 – 1.3) eV [1–3] T1/2(2nbb) = [ 9.6 ± 0.3 (stat) ± 1.0 (syst) ]  1019 y (Phys. Rev. Lett. 95 (2005) 182302) T1/2 (0nbb) > 2.1 × 1023 y(90% CL) mn < (1.4 – 2.2) eV [1–3] [1] M.Kortelainen and J.Suhonen, Phys.Rev. C 75 (2007) 051303(R). [2] M.Kortelainen and J.Suhonen, Phys.Rev. C 76 (2007) 024315. [3] V.A.Rodin et al., Nucl.Phys. A 793 (2007) 213. NME:

  14. Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 0nbb decay search Collaboration decided to perform blind analysis Analysis is now under way Results will be ready soon Data acquisition with NEMO 3 until the end of 2010 expected sensitivities in 2010: 100Mo T1/2(0) > 2 × 1024 y (90 % CL) mn < (0.4 – 0.7) eV 82Se T1/2(0) > 8 × 1023 y (90 % CL) mn < (0.7 – 1.1) eV [1] M.Kortelainen and J.Suhonen, Phys.Rev. C 75 (2007) 051303(R). [2] M.Kortelainen and J.Suhonen, Phys.Rev. C 76 (2007) 024315. [3] V.A.Rodin et al., Nucl.Phys. A 793 (2007) 213. NME:

  15. NEMO 3 SuperNEMO Me Tobs NA T1/2 (0nbb) > ln 2   A Nexcluded A N90 150Nd or 82Se isotope 100Mo isotope mass M 100 – 200 kg 7 kg A(208Tl) < 2 mBq/kg if 82Se: A(214Bi) < 10mBq/kg A(208Tl): < 20 mBq/kg A(214Bi): < 300 mBq/kg internal contamination 208Tl and 214Bi in the bb foil ~ 30 % efficiency 8 % energy resolution (FWHM) 8% @ 3 MeV 4% @ 3 MeV T1/2(0nbb) > 2 × 1026 y m < (50 – 100) meV T1/2(0nbb) > 2 × 1024 y m < (0.3 – 0.6) eV Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 From NEMO 3 to SuperNEMO

  16. ~ 90 physicists,12 countries, 27 laboratories Japan U Saga KEK U Osaka Morocco Fes U USA MHC INL (U Texas) Poland U Warszawa Finland U Jyväskylä Russia JINR Dubna ITEP Moscow Kurchatov Institute United Kingdom UCL U Manchester Imperial College Ukraine INR Kiev ISMA Kharkov France CEN Bordeaux IPHC Strasbourg LAL ORSAY LPC Caen LSCE Gif s/Yvette Slovakia (U Bratislava) Spain U Valencia U Zaragoza U Barcelona Czech Republic Charles U Prague CTU Prague Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 SuperNEMO Collaboration

  17. Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 SuperNEMO preliminary design • Planar geometry Source (40 mg/cm2) 12 m2 , tracking volume (~ 3000 channels) and calorimeter (~ 1000 PMT) • Modular (~ 5 kg of enriched isotope/module) 100 kg: 20 modules ~ 60 000 channels for drift chamber ~ 20 000 PMT channels (3000 if bar design) 4 m 1 m 5 m Top view Side view

  18. Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 SuperNEMO design study • February 2006 – July 2009 • Approved in UK, France and Spain. Smaller but vital contributions from USA, Russia, Czech Republic, Japan. • Main tasks and deliverables: • R&D on critical components • Calorimeter energy resolution of 4% at 3 MeV • Optimisation of tracking detector and construction (robot) • Better background rejection (e.g. extra veto counters) • Ultrapure source production and purity control • Simulations and geometry optimisation (B-field question) • Technical Design Report • Experimental site selection (Modane, Canfranc, Gran Sasso)

  19. Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 Choice of isotope Choice of nucleus depends on: • enrichment possibilities • high Q value • phase space factor G0 • 2 half-life 1 2 = GMm2 T0n Two main options: 150Nd82Se Qbb (MeV) 3.3672.995 G0 (y-1eV-2) 8×10-2510-25 • purification of 4 kg of 82Se underway (INL, USA) • enrichment of 150Nd possible in France (MENPHIS facility at CEA – Atomic Vapour Laser Isotope Separation) 82Se obtained by centrifugation. Impossible for 150Nd, only laser enrichment.

  20. Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 Calorimeter R&D • Energy resolution is a combination of energy losses in the foil and calorimeter DE/E • Goal: FWHM  7%/E  4% at 3 MeV • Studies • – Material: organic (plastic or liquid) • – Geometry and shape (block or bar) • – Size • – Reflective coating • – PMTs (Photonis, Hamamatsu, ETL) • High QE • Ultra-low background

  21. Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 Calorimeter R&D status • Focus on large block studies (~ 20 cm, 8” PMT) • Four routes pursued • 8” PMT + plastic block • 8” PMT + liquid scintillator • 8” PMT + hybrid (liquid + plastic) scintillator • 2 m scintillator bar with 3” or 5” PMTs • PMTs • Working closely with manufacturers: Hamamatsu, Photonis, ETL • Real breakthrough in high-QE PMTs from Hamamatsu, Photonis: 43% QE from 3’’ PMTs, now working on 8’’ • Deep involvement in ultra-low background PMT development (especially Photonis) • 8% at 1 MeV achieved with 20 cm blocks, standard PMT (27% QE) and reflectors • Extrapolating the above improvements gives 7% but must be tested once all components are in hand • Plan B: 3”/5” high QE PMTs and larger number of channels • Decision on calorimeter design in December 2008

  22. Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 Tracker R&D • Optimise operating parameters: • – wire length and diameter • – wire material, gas mixture • – readout • Several single cells, two 9-cell prototypes built and tested • 90-cell prototype is being built • Drift cell working in Geiger mode (Geiger cell) • Transverse position from electron drift times • Longitudinal position from plasma propagation times 9-cell prototype in Manchester

  23. Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 Tracker automated wiring • About 500 000 wires to be strung, crimped, terminated • Wiring robot is being developed at Mullard Space Science Lab (UCL) Clamp mechanism Pair of end fittings Anode wire feed mechanism

  24. Prompt e–, T0 Scintillator + PMT 238U e– 214Po Tracking (wire chamber) (164 ms) b Source foil to be measured 214Bi (19.9 mn) a a 210Pb 22.3 y 0.021% Radon + neutron + g shield Delayed a T1/2 ~ 300 ns, Edeposited ~ 1 MeV 210Tl (1.3 mn) 232Th 212Po (300 ns) b 212Bi (60.5 mn) a 208Pb (stable) 36% 208Tl (3.1 mn) Bi-Po process Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 Radiopurity measurement • BiPo detector to measure contaminations of 208Tl and 214Bi in source foils before installation in SuperNEMO • Goal: ~ 5 kg of foil (12 m2 , 40 mg/cm2) in one month with a sensitivity of • A(208Tl) < 2 mBq/kg&A(214Bi) < 10 mBq/kg Background < 1 event/month!

  25. Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 BiPo-1 capsule Radiopurity measurement BiPo-1 capsule BiPo-2 Set of BiPo-1 capsules BiPo-1: 18 capsules in operation in LSM Modane since February 2008 current sensitivity A(208Tl) < 5 µBq/kg BiPo-2 and Phoswhich: installed in LSM Modane and running since July 2008 results expected by the end of 2008

  26. Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 SuperNEMO schedule 2007 2008 2009 2010 2011 2012 2013 2014 NEMO 3 running SuperNEMO design study BiPo1 Canfranc/LSM BiPo construction BiPo installation BiPo running @ Canfranc SuperNEMO 1st module construction Preparation of new LSM site Construction of 20 modules Construction of 20 modules 1 – 5 SuperNEMO modules running at Canfranc Running full detector in 2014 Target sensitivity (0.05 – 0.1 eV) in 2016 SuperNEMO modules installation at new LSM

  27. Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 Summary • NEMO 3 • Unique approach combining tracking and calorimetry • 2nbb factory  precise T1/2 measurement for 7 isotopes: new results for 48Ca, 96Zr, 130Te and 150Nd • 0nbb of 100Mo & 82Se: blind analysis of Phase 2 data under way • Data taking until the end of 2010 • Ideal test bench for SuperNEMO • SuperNEMO • 3 year design study addresses most critical issues: calorimeter resolution, tracker optimisation, radio-purity • Based on design study results full proposal for 100+ kg detector in 2009 • Start-up in stages due to modular approach: first module by 2010/11, all 20 modules ~ 2013 • Target sensitivity 50 – 100 meV by 2016

  28. Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 Backup slides

  29. Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 cathode rings (wire chamber) iron shielding water tank PMT scintillators bb isotope foils calibration tube coil

  30. (164 ms) b a Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 Radon trapping facility Phase I : February 2003 – September 2004 (radon background in data) ~ 1 0nbb-like event/y/kg with 2.8 < E1+E2 < 3.2 MeV 238U 214Po Phase II : since October 2004 (radon level reduced by a factor of 10) 214Bi (19.9 mn) 1 ton of charcoal @ –50oC, 9 bars air flux = 150 m3/h Input: A(222Rn) 15 Bq/m3 Output: A(222Rn) < 15 mBq/m3 !!! reduction factor of 1000 Bi-Po process 210Pb (22.3 y) 0.021% 210Tl (1.3 mn) 0.015 Bq/m3 Inside the NEMO 3 tent: factor of 100 – 300 Inside NEMO 3: factor of 10 A(222Rn)  2 mBq/m3 Radon background for 0nbb search is then negligible for Phase 2

  31. 219 000 events 6914 g 389 days S/B = 40 219 000 events 6914 g 389 days S/B = 40 ● Data ● Data 2b MC simulation 2b MC simulation Background subtracted Background subtracted cos(ee) E1 + E2 (MeV) Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 2nbb decay of 100Mo Phase I data (February 2003 – October 2004) with radon Energy sum of the electrons Angular distribution NEMO-3 NEMO-3 T1/2 = [ 7.11 ± 0.02 (stat) ± 0.54 (syst) ]  1018 y Phys. Rev. Lett. 95 (2005) 182302 Now we have 0.5M events and the result will be updated later this year

  32. 2750 events 932 g 389 days S/B = 4 ● Data 2b MC simulation Background subtracted E1 + E2 (MeV) Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 2nbb decay of 82Se Phase I data (February 2003 – October 2004) with radon Energy sum of the electrons NEMO-3 T1/2 = [ 9.6 ± 0.3 (stat) ± 1.0 (syst) ]  1019 y Phys. Rev. Lett. 95 (2005) 182302

  33. External background 208Tl (PMTs) Measured with (e-g) external events ~ 10-3 0nbb-like events y-1·kg -1 with 2.8<E1+ E2<3.2 MeV External neutrons and high energy g’s Measured with (e-e+)int events with E1+E2 > 4 MeV  0.02 0nbb-like events y-1·kg -1 with 2.8<E1+ E2<3.2 MeV 208Tl impurities inside the foils Measured with (e-2g), (e-3g) events coming from the foil ~ 0.1 0nbb-like events y-1·kg -1 with 2.8<E1+ E2<3.2 MeV 100Mo 2nbb decayT1/2 = 7.1 × 1018 y ~ 0.3 0nbb-like events y-1·kg -1 with 2.8<E1+ E2<3.2 MeV Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 Background measurement in NEMO 3 NEMO 3 can measure each component of its background!

  34. Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 Future extension of LSM Modane lab

  35. Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 New LSC Canfranc laboratory ROAD TUNNEL Ultra-Low background Facility 15 × 10 m (h=8 m) Main Hall 40 × 15 m (h=11 m) Access gallery installations, clean rooms & offices RAILWAY TUNNEL Old Laboratory 20 × 5 m (h=4.5 m) • BiPo • SuperNEMO • Dark matter • …

  36. Enriched U collecting plate Vaporised isotope mixture Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 150Nd laser enrichment AVLIS: Atomic Vapour Laser Isotope Separation Selective photo-ionisation:based on isotope shifts in the atomic absorption optical spectra U + 3 selective photons →235U+ + e– Depleted U collecting plate Laser beam • 150Nd enrichment is technically possible • MENPHIS facility (CEA/Pierrelatte - France)

  37. Ladislav Vála, Results of NEMO 3 and status of SuperNEMO, NOW 2008, 9th September 2008 AVLIS facility 200+ kg of 2.5% enriched Uranium produced MENPHIS • Facility stopped in 2003 • Principal agreement by CEA to suspend closure/dismantling • 150Nd enrichment collaboration formed. SuperNEMO and SNO++ plus other interested parties • Phased approach • Feasibility studies for high degree enrichment (> 50%) • ~ kg production and tests • 100+ kg production

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