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SuperNEMO: next generation project to search for neutrinoless double beta decay. Yu. Shitov, Imperial College, London. From NEMO-3 to SuperNEMO Choice of nucleus for measurments Calorimeter R&D Low background R&D Tracker R&D Sensitivity simulations Location choice Schedule
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SuperNEMO: next generation project to search for neutrinoless double beta decay Yu. Shitov, Imperial College, London • From NEMO-3 to SuperNEMO • Choice of nucleus for measurments • Calorimeter R&D • Low background R&D • Tracker R&D • Sensitivity simulations • Location choice • Schedule • Current status and roadmap of 0nbb-projects • Conclusion
NEMO-3/SuperNEMO collaboration Neutrino Ettore Majorana Observatory (Neutrino Experiment on MOlybdenum – historical name) Japan U Saga U Osaka Morocco Fes U USA MHC INL U Texas Russia JINR Dubna ITEP Moscow Kurchatov Institute UK UCL U Manchester Imperial College Finland U Jyvaskyla Poland U Warsaw Ukraine INR Kiev ISMA Kharkov France CEN Bordeaux IReS Strasbourg LAL ORSAY LPC Caen LSCE Gif/Yvette Slovakia (U. Bratislava) Spain U Valencia U Saragossa U Barcelona Czech Republic Charles U Praha IEAP CTU Praha ~ 80 physicists, 12 countries, 27 laboratories. R&D Program for 02/2006-07/2009 is being carring out. Major contributors: UK, France, Spain. Smaller but vital contributions from US, Russia, Czech Republic, Japan. XX Rencontres de Blois, Shitov Yu., ICL, 21/05/2008
NEMO-3 SuperNEMO 7 kg 100Mo T1/2(bb2n) = 7. 1018 y Mass of isotope 100-200 kg 82Se||150Nd T1/2(bb2n) = 1020 || 1019 y T1/2(bb0n) > 2. 1024 y <mn> < 0.3 – 1.3 eV Sensitivity T1/2(bb0n) > 2. 1026 y <mn> < 40 – 100 meV Energy resolution (FWHM of the bb0n ray) Total:FWHM ≤7 % at 1 MeV Calorimeter:≤4 % at 3 MeV FWHM ~ 12% at 3 MeV (dominated by calorimeter ~ 8%) From NEMO to SuperNEMO Me Tobs NA T1/2 (bb0n) > ln 2 A N90 e(bb0n) ~ 30 % e(bb0n) = 18 % Efficiency 214Bi < 300 mBq/kg 208Tl < 20mBq/kg Internal contaminations in the source foils in 208Tl and 214Bi (If 82Se) 214Bi < 10 mBq/kg 208Tl < 2mBq/kg bb2n=1, 208Tl =0.5 214Bi=0.5 cnts/100 kg/y bb2n ~ 2 cts / 7 kg / y (208Tl, 214Bi) ~ 0.5 cnts/7 kg/y Background NEMO-3 successful experience shows us that technique can be extrapolated for larger mass next generation detector to reach new sensitivity level. XX Rencontres de Blois, Shitov Yu., ICL, 21/05/2008
SuperNEMO basic design Plane geometry Source (40 mg/cm2) 12m2 , tracking volume (~3000 channels) and calorimeter (~1000 PMT) 4 m Modular (~5 kg of enriched isotope/module) 100 kg: 20 modules ~ 60 000 channels for drift chamber ~ 12 000/20 000 channels for 5’’/8’’ PMT 4 m 1 m 5 m Top view Side view XX Rencontres de Blois, Shitov Yu., ICL, 21/05/2008
Choise of nucleus for measurements Recent calculations: Shell Model: Caurier et al. (2004)&private com. QRPA Simkovic et al. (1999) Stoica et al. (2001) Suhonen et al. (1998 and 2003) Rodin, Simkovic (2005) Nucleus choice depends on: • enrichment possibilities • experimental techniques • NME value (not very strong due to calculation uncertainties) • Qbbvalues (phase space factor, background) • high bb(2n) life-time Uncertainties in nuclear matrix elements (NME) theoretical calculations – essential problem XX Rencontres de Blois, Shitov Yu., ICL, 21/05/2008
Choise of nucleus for measurements Compilation of QRPA & Shell model (MEDEX'07 workshop) Shell model only Deformation is not taken into account Two main options: 82Se and 150Nd. 82Se obtained by centrifugation. Impossible for 150Nd, only laser enrichment XX Rencontres de Blois, Shitov Yu., ICL, 21/05/2008
Installation of NEMO3 foils (LSM) • ITEP; Collaboration with Kurchatov and Nizhnij-Novgorod institutes (distillation) • 1 kg (ITEP, done&checked) + 2 kg of natSe done R&D for 82Se sources ECP (Electro-Chemical Plant, Svetlana) Zelenogorsk (Siberia) Enrichment Goal: To be able to produce 100 kg of 82Se • Facilities exist in Russia • 30 kg of 76Ge for GERDA • 100 kg of 82Se possible in 3 years - Distillation of 82Se (for purification) possible Distillation of 116Cd tested with NEMO-3 - 3.5 kg of 82Se funded by ILIAS(*) (2005-2007) Purification Goal:208Tl < 2 mBq/kg 214Bi < 10 mBq/kg • Collaboration with INL (chemical method) • 600 g of natSe done • 1 kg 82Se done • All funded by ILIAS Source foils production Goal: 250 m2 of 82Se foils of 40 mg/cm2 NEMO3: ITEP (Moscow) powder + glue (60mg/cm2) =>Extrapolation 100 kg possible if very clean conditions. Or new technique is in test in LAL Chemical purification at INL (US) XX Rencontres de Blois, Shitov Yu., ICL, 21/05/2008
R&D for 150Nd • technically it is potencially possible to enrich Nd (MENPHIS/CEA), strongly supported by the international double beta decay community 150Nd advantages - no constraint for Radon and 214Bi - constraint less severe for 208Tl - phase space: 100 kg 150Nd 1 700 kg of 76Ge 400 kg of 82Se or 130Te 4000 kg of 136Xe - nuclear matrix element : could be good but ? - if SUSY is a mediator : very good for Nd - search to bb-transition to excited state level very promising too Nd is the candidate for SuperNEMO (2 electrons search) and for SNO++ (pure calorimeter) XX Rencontres de Blois, Shitov Yu., ICL, 21/05/2008
Evaporator Dye laser chain Yag laser Copper vapor laser Expression of Interest of SuperNEMO, SNO++ to keep MENPHYS for Nd enrichment 150Nd R&D: MENPHIS facility support Based on AVLIS (Atomic Vapor Laser Isotope Separation) method of enrichement Design : 2001 Building : 2002 1st test : early 2003 1st full scale exp. : june 2003 • Production of 200 kg of enriched U at 2.5 % in few days • Results in agreement with simulation expectation MENPHIS simulation shows that enrichment of 150Nd is doable (ton scale), ~ 100 kg 48Ca enrichment is theoriticaly doable. Studies must be done XX Rencontres de Blois, Shitov Yu., ICL, 21/05/2008
Calorimeter R&D • Energy resolution is a combination of energy losses in foil and calorimeter DE/E • Goal: 7-8%/√E 4% at 3 MeV (82Se Qbb) • Studies: • Material: organic plastic (PS) or • liquid (LS) scintillators • Geometry and shape (block, bar) • Size • Reflective coating • PMT • High QE • Ultra-low background 207Bi source Factor of 2 compared to NEMO3! Hamamatsu high-QE PMT BC404 PS in teflon Cuvette with LS DE/E = 6.5% at 1 MeV 3.8% at 3 MeV • Required resolution achieved for small ~5-6 cm samples for both LS and PS scintillators. Bicron is best so far but other manufacturers competing (ISM, Kharkov, Dubna) • Real challenge starts from scintillators with ~10 x 10 cm surface size. XX Rencontres de Blois, Shitov Yu., ICL, 21/05/2008
Calorimeter R&D • Focus on large block studies (~20cm, 8” PMT) • Four routes pursued • 8” PMT + plastic block • 8” PMT + liquid scintillator • 8” PMT + hybrid (liquid + plastic) scintillator • 2m scint. bar with 3” or 5” PMTs • PMTs • Working closely with manufacturers: Hamamatsu, Photonis, ETL • Real breakthrough in high-QE PMTs from Hamamatsu and Photonis: 43% QE • First large (8”) high-QE Hamamatsu PMT is under test • Deep involvement in ultra-low background PMT development (especially Photonis) • Enhanced reflectors available. 98% reflectivity instead of usual 93% • First tests with high-QE 8’’ PMT are encouraging: 8%-8/5% for LS/PS with 15-20 cm. Further intensive tests are in progress. • Plan B: 3”/5” high QE PMTs and larger number of channels. • Decision on calorimeter design in December 2008. 8” High-QE Hamamatsu PMT XX Rencontres de Blois, Shitov Yu., ICL, 21/05/2008
11 m 12 m Alternative SuperNEMO sandwich bar design SC bars double sided with PM. Only ~ 3000 relatively cheap (3’’||5’’) PM (~12000 8’’ PM in basic design). More compact, less background from PM, but worse resolution (~10-11%). Simulations are in progress. XX Rencontres de Blois, Shitov Yu., ICL, 21/05/2008
R&D for bar scintillators 11-12% resolution has been obtained without optimization New tests with improved setup are in progress. XX Rencontres de Blois, Shitov Yu., ICL, 21/05/2008
e- prompt e- 238U 214Po Qb (212Bi) = 2.2 MeV a (164 ms) b 214Bi (19.9 mn) Delay a a 210Pb 22.3 y Scintillator + PMT 0.021% T1/2 ~ 300 ns Edeposited ~ 1 MeV 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 23 m2→ 12 m2 Background < 1 event / month 208Tl (3.1 mn) Bi-Po Process Low background measurement R&D: BiPo detection method • To measure contaminations of 208Tl and 214Bi in source foils before installation in SuperNEMO • Goal: ~5kg of foil (12m2 , 40mg/cm2) in one month with a sensitivity of • 208Tl < 2 mBq/kg • 214Bi < 10mBq/kg • (e.g. sensitivity limit of “standard” 400cm3HPGe detector 60 mBq/kg in 208Tl and 200 mBq/kg in 214Bi for 1 month) XX Rencontres de Blois, Shitov Yu., ICL, 21/05/2008
Low background measurement R&D: BiPo prototypes BiPo-1 capsule Set of BiPo-1 capsules BiPo-1 capsule BiPo-1: 10 capsules in operation since 12/2007, current sensitivity < 7.5 µBq/10m2 x 40 mg foil BiPo-2 and Phoswhich: started in 04/2008: results expected in the end of 2008 BiPo-2 XX Rencontres de Blois, Shitov Yu., ICL, 21/05/2008
R&D for tracker • Goal: tracker performance optimization • sizes of wires and cell (3-5 cm) • wire material, gas mixture, readout • simulation for optimal tracker desing • desing of automatic wiring equipment • 9-cell prototype (in photo) has been built and tested with cosmics in Manchester University: • perfomances are ok, optimized for autowiring; • different configurations (8-12 cathod wires per cell) have been tested. • 3cm, 4.4 cm and 5cm cells have been tested with different setups using laser. Preliminary results show the close performances. • 90-cell prototype (below) is in production and will be ready this summer. • final choise of SuperNEMO tracker: 12/2008. - Transverse position from electron drift times - Longitudinal position from plasma propagation times Drift cell worked in Geiger mode Revised 90-cell prototype XX Rencontres de Blois, Shitov Yu., ICL, 21/05/2008
R&D for wiring robot XX Rencontres de Blois, Shitov Yu., ICL, 21/05/2008
Simulations 82Se 150Nd “Conservative” scenario Sensitivity 82Se: T1/2(0n) =1-1.5 1026 y depending on final mass, background and efficiency <mn> 0.06 – 0.1 eV (includes uncertainty in T1/2) – MEDEX’07 NME 150Nd: T1/2(0n) =0.5 1026 y <mn> 0.045 eV (but deformation not taken into account) XX Rencontres de Blois, Shitov Yu., ICL, 21/05/2008
Possible SuperNEMO location cites
New LSC Canfranc laboratory ROAD TUNNEL Ultra-Low background Facility 15 x 10 m (h=8 m) Main Hall 40 x 15 m (h=11 m) Access gallery Old Laboratory 20 x 5 m (h=4.5 m) installations, clean rooms & offices RAILWAY TUNNEL • BiPo • SuperNEMO • - Dark matter • - …. XX Rencontres de Blois, Shitov Yu., ICL, 21/05/2008
Future extension of LSM laboratory Could be available for 2012 XX Rencontres de Blois, Shitov Yu., ICL, 21/05/2008
2010 2011 2007 2008 2009 2012 2013 BiPo construction SuperNEMO schedule summary Schedule Summary 2014 NEMO3 Running SuperNEMO Design Study BiPo1 Canfranc/LSM BiPo installation BiPo running @ Canfranc SuperNEMO 1st module construction Preparation of new LSM site 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 XX Rencontres de Blois, Shitov Yu., ICL, 21/05/2008
0nbb experiments overview World-wide double beta-decay projects * Matrix elements from MEDEX’07 or provided by experiments XX Rencontres de Blois, Shitov Yu., ICL, 21/05/2008
Roadmap for double beta-decay projects NEMO 3 CUORICINO, EXO-200 HM Claim GERDA SuperNEMO CUORE,EXO 2015-2020, 1t experiments (1 or 2) >2020, >10t experiment XX Rencontres de Blois, Shitov Yu., ICL, 21/05/2008
Conclusion • - The 0nbb-decay is a test of physics beyond the Standard Model by the search of the • leptonic number violation and would determine the nature of the neutrino (Majorana), absolute neutrino mass scale and neutrino hierarchy. • - Several experiments are needed to measure different sources with several techniques. • NEMO-3 technique can be extrapolated at ~100 kg to be sensitive to 2.1026 y • Only tracko-calo (SuperNEMO) and gas TPC can directly register 0nbb-decay. In the case of discovery only direct methods will allow to determine the process leading to bb(0n) : light neutrino exchange, right-handed current, supersymmetry, etc. • 3-year SuperNEMO R&D program is carrying out and it is in good shape. Key challenges are calorimeter resolution, isotope choice, and radio purity. Based on design study results full proposal for 100+ kg detector in 2009. “Last minute” isotope change possible. E.g. CUORE sees the signal in 130Te. • First module 2010/11 • All 20 modules ~2013 • Target sensitivity: 50-100 meV by 2016, which is competitive with the other next generation 0nbb-experiments. • - The next generation of bb(0n) detectors will improve by a factor of 100/10 the sensitivity to T1/2 / <mn> respectively. XX Rencontres de Blois, Shitov Yu., ICL, 21/05/2008