1 / 22

NEMO 3 and SuperNEMO experiments

NEMO 3 and SuperNEMO experiments. Vladimir Vasiliev, UCL 2-6 May ’06, Stockholm on behalf of NEMO and SuperNEMO collaborations

dympna
Download Presentation

NEMO 3 and SuperNEMO experiments

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. NEMO 3 and SuperNEMO experiments Vladimir Vasiliev, UCL 2-6 May ’06, Stockholm on behalf of NEMO and SuperNEMO collaborations NEMO collaboration: IReS, Strasbourg, France; LAL, Orsay, France; INEEL, Idaho Falls, USA; ITEP, Moscow, Russia; CENBG, Bordeaux-Gradignan; JINR, Dubna, Russia; IEAP, Prague, Czech Republic; UCL, London, UK; LPC, Caen, France; Saga Universityt, Japan; LSCE, Gif-sur-Yvette, France; Jyvaskyla University, Finland; MHC, South Hadley, USA; Charles University, Prague, Czech Republic; Manchester University, UK. SuperNEMO collaboration: CENBG Bordeaux-Gradignan; IReS, Strasbourg, France; LAL, Orsay, France; LPC, Caen, France; LSCE Gif-Sur-Yvette, France; Jyvaskula Uiversity, Finland; Saga University, Japan; Osaka University, Japan; Fes University, Marocco; INR RAS, Moscow, Russia; ITEP, Moscow, Russia; JINR, Dubna, Russia; RRC Kurchatov Institute, Moscow, Russia; Charles University, Prague, Czech Republic; Technical University, Prague, Czech Republic; Manchester University, UK; UCL, London, UK; ISMA, Kharkov, Ukraine; INEEL Idaho Falls, USA; Mount Holyoke College, USA; University of Texas, USA; IFIC, Valencia, Spain; Canfranc laboratory, Zaragosa, Spain; NEMO 3 and SuperNEMO experiments

  2. Neutrinoless bb decay • Experimental signature: • 2 electrons • Eb1+ Eb2=Qbb NEMO 3. Tracking experiment a) and b). Better signature, control and suppression of background. But worse resolution. Ultimate background – 2b2n decay tail. NEMO 3 and SuperNEMO experiments

  3. B(25 G) 20 sectors 3 m 4 m NEMO-3 detector Frejus underground laboratory 4800 m.w.e. Source: 10 kg of  isotopes, foil ~ 50mg/cm2 Tracking detector:drift wire chamber operating in Geiger mode (6180 cells) Gas: He + 4% ethyl alcohol + 1% Ar + 0.1% H2O sxy=0,6 cm; sz=1,3 cm; Calorimeter: 1940 plastic scintillators coupled to low radioactivity PMTs FWHM=14% (5”); 17% (3”) @ 1MeV Time resolution = 0.25 ns @ 1MeV g detection efficiency ≈ 50 % Magnetic field: 25 Gauss (3% e+/e- confusion @ 1 MeV) Gamma shield: Iron (e = 18 cm) Neutron shield: 30 cm water + boron (ext. wall);40 cm wood (top and bottom) Able to identify e-, e+, g and a NEMO 3 and SuperNEMO experiments

  4. Cathodic rings Wire chamber PMTs Calibration tube scintillators bb isotope foils NEMO 3 and SuperNEMO experiments

  5. bb2n measurement 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 Background measurement natTe491 g 100Mo6.914 kg Qbb = 3034 keV 82Se0.932 kg Qbb = 2995 keV Cu621 g bb0n search bb isotopes in NEMO-3 NEMO 3 and SuperNEMO experiments

  6. Cu foil Background model • External background • Detector radioactivity (PMT, iron, g flux from lab). Measured by g Compton scattering in the foil. • Radon in tracking chamber • 214Bi pollution of wires and foil surfaces. Measured by delayed 214Po a-decay. • Source foil • Internal radioactivity. e and eg events from foil. • bb2n decay NEMO 3 and SuperNEMO experiments

  7. adsorption unit @ -50°C 15 Bq/m3 buffer 15 mBq/m3 compressor 9-10 bar dryer cooler & heater Radon free air facility In the tent around NEMO 3 Rn = 150 mBq/m3 In the tracker Rn = 4.5 mBq/m3  does not depend any more from Rn level in the tent. 2 sets of data Phase-I, before 4/10/04, Rn ≈ 22.2 mBq/m3, Phase-II, Rn=4.5 mBq/m3 NEMO 3 and SuperNEMO experiments

  8. HSD, higher levels contribute to the decay SSD simulation 1+ SSD, 1+ level dominates in the decay (Abad et al., 1984, Ann. Fis. A 80, 9) 100Tc 0+ 100Mo Single electron spectrum different between SSD and HSD Simkovic, J. Phys. G, 27,2233, 2001 Esingle (keV) bb results for 100Mo T1/2 = 7.11 ± 0.02 (stat) ± 0.54 (syst)  1018 y Phys Rev Lett 95, 182302 (2005) SSD model confirmed Decay to the excited 0+ state of 100Ru T1/2 = 5.7 ± 1.3 (stat) ± 0.8 (syst)  1020 y To be published soon bb0n Phase I + II ( 587d) Use MC Limit approach: shape information, different background level for PI and PII E1+E2>2 MeV 12952 evs MC = 12928 ± 70 e0n=18.1 % T1/2 > 5.6∙1023 y, 90% CL Window method [2.78-3.20] MeV, (690d) 14 evs MC = 13.4 e0n=8.2 % T1/2 > 5.8∙1023 y, 90% CL NEMO 3 and SuperNEMO experiments

  9. bb results for 82Se T1/2 = 9.6 ± 0.3 (stat) ± 1.0 (syst)  1019 y Phys Rev Lett 95, 182302 (2005) bb0n Phase I + II ( 587d) Use MC Limit approach E1+E2>2 MeV 238 evs MC = 240.5 ± 7 e0n=17.6 % T1/2 > 2.7∙1023 y, 90% CL Window method [2.62-3.20] MeV, (690d) 7 evs MC = 6.4 e0n=14.4 % T > 2.1∙1023 y, 90% CL NEMO 3 and SuperNEMO experiments

  10. bb2n decay for other isotopes 116Cd, T1/2=(2.8±0.1(stat)±0.3(syst))∙1019 y 150Nd , T1/2=(9.7±0.7(stat) ±1.0(syst))∙1018y 96Zr, T1/2 =(2.0±0.3(stat)±0.2(syst))∙1019y 48Ca, T1/2=(5.3±0.9(stat)±0.5(syst))∙1019 y Very preliminary results, to be crosschecked and published soon NEMO 3 and SuperNEMO experiments

  11. Exotic processes search • V+A current in electroweak lagrangian • Neutrino coupled axions c (majorons) *new PI+PII data ** R.Arnold et al. Nucl. Phys. A765 (2006) 483 NME Calculations: [1] J. Suhonen, Nucl. Phys. A 700 (2002) 649 [2] M. Aunola and J. Suhonen, Nucl. Phys. A 463 (1998) 207 [3] F. Simkovic et al., Phys. Rev. C 60 (1999) 055502; S.Stoica and H. Klapdor-Kleingrothaus, Nucl. Phys. A 694 (2001) 269; O. Civatarese and J. Suhonen, Nucl. Phys. A 729 (2003) 867 NEMO 3 and SuperNEMO experiments

  12. SuperNEMO project • extension of NEMO 3 technique • 100 kg of isotopes, thin source between tracking volumes, surrounded by calorimeter. • sensitivity 1-2∙1026 y, 40-70 meV • main improvements needed: • energy resolution (8% FWHM @ 1MeV ≡ 4% @ 3MeV) • detection efficiency (factor 2) • source radio purity (factor 10) • background rejection methods NEMO 3 and SuperNEMO experiments

  13. SuperNEMO milestones • 2006-8:Design study • Calorimeter • Tracker • Source • Site selection (Frejus, Gran Sasso, Canfranc, Bulby) Approved and funded R&D program in UK and France. Spain, Russian and Japan groups applied for funding. • end 2008:Full Proposal • 2009 – 2011: Production • 2010-2011:Start taking data • 2015:planned sensitivity ~0.04 eV NEMO 3 and SuperNEMO experiments

  14. source tracker calorimeter 1 m 4 m 5 m Top view Side view Modular design NEMO 3 and SuperNEMO experiments

  15. Alternative design (bar scintillator) Double sided readout NEMO 3 and SuperNEMO experiments

  16. Calorimeter R&D so far • 7-8% FWHM @ 1MeV for small scintillator 5x5x2 cm • 9% FWHM @ 1 MeV for 15x15x2 cm … but because of light guide! • 11-13% FWHM @ 1 MeV for 200 cm bar scintillator. Attenuation length 150 cm! looking for better plastic. NEMO 3 and SuperNEMO experiments

  17. Wiring robot The challenge: from 6,000 to ~60,000+ cells • Wires must be • strung • terminated • crimped • This can not be done • manually (~10 min/wire) • Complications • Copper pick-ups • Must be cost effective • Solder can not be used (radiopurity) NEMO 3 and SuperNEMO experiments

  18. e- prompt e- Qb(214Bi)=3.2 Me Bi-Po Process 238U 214Po Qb (212Bi) = 2.2 MeV a (164 ms) b 214Bi (19.9 mn) Delay a a 210Pb 22.3 y T1/2 ~ 300 ns Edeposited ~ 1 MeV Scintillator + PMT 0.021% 210Tl (1.3 mn) Tracking (wire chamber) 232Th Source foil (40 mg/cm2) 212Po (300 ns) b 212Bi (60.5 mn) Shield radon, neutron,g a 208Pb (stable) 36% 2 modules 23 m2→ 12 m2 Background < 1 event / month e- a delay 208Tl (3.1 mn) BiPo device, ultra low purity msr. WHY? g spectroscopy doesnt sensitive to purity level required ~10 mBq/kg NEMO 3 and SuperNEMO experiments

  19. Isotope choice Detector allows to hold any isotope. Choice depends on: - enrichment possibilities. Obligatory! - Qbbvalue (phase space factor, background) - bb(2n) life-time • 82Se good candidate • 100 kg per 2-3 y enrichment rate possible in Russia • Qbb= 2995 keV. Concern about 214Bi and 208Tl only. • test 2kg sample produced. Under purification now • 150Nd even better! • SILVA group (SACLAY, France) was contacted. 150Nd enrichment is possible! • Qbb= 3367 keV. Concern about 208Tl only • Large phasespace. 2n tale only 1.6 bigger then for 82Se • NME & G0n much better then for 82Se NEMO 3 and SuperNEMO experiments

  20. Conclusion • NEMO 3 is continuing to take data • no bb0n signal so far. • 100Mo: T1/2>5.8∙1023 y; mn<0.6-1.0 eV* • 82Se: T1/2>2.1∙1023 y; mn<1.2-2.5 eV* *F. Simkovic et al., Phys. Rev. C 60 (1999) 055502; S.Stoica and H. Klapdor-Kleingrothaus, Nucl. Phys. A 694 (2001) 269; O. Civatarese and J. Suhonen, Nucl. Phys. A 729 (2003) 867 • a number of bb2n results to be published soon • SuperNEMO R&D is in progress. 3 year program funded in UK and France. NEMO 3 and SuperNEMO experiments

  21. WE ARE IN THE MIDDLE OF THE ROAD

  22. EXIT THAT COULD LEAD BEYOND SM thank you for your attention!

More Related