Probing neutrino mass with SuperNEMO Ruben Saakyan Ulisse at LSM Workshop 30 June 2008

30-Jun-2008 R. Saakyan: Ulisse at LSM Workshop. 2 Outline The Concept The Detector Physics reach Status of design study Schedule Summary

30-Jun-2008 R. Saakyan: Ulisse at LSM Workshop. 3 Neutrinoless double beta decay (  )  L = 2! Lepton number violation parameter can be due to, V+A, Majoron, SUSY, H -- or a combination of them! Need detectors which can probe different mechanisms (and different isotopes)

30-Jun-2008 R. Saakyan: Ulisse at LSM Workshop. 4 >.. AA M. t N Bkg.  E ln2. N k C.L. (y) SuperNEMO experimental technique M: masse (g)  : efficiency K C.L. : Confidence level N: Avogadro number t: time (y) N Bckg : Background events (keV -1.g -1.y -1 )  E: energy resolution (keV) Focus on lowering N bkg and open-minded search for any lepton violating process Calorimetry + Tracking Build on NEMO3 experience Reconstruct two electrons in the final state (E 1 +E 2 = Q  ) Measure several final state observables Individual electron energies Electron trajectories and vertices time of flight Angular distribution between electrons Background rejection through particle ID: e -, e +, ,  Sources separated from detector  can measure different isotopes

30-Jun-2008 R. Saakyan: Ulisse at LSM Workshop. 5 From NEMO-3 to SuperNEMO 7 kg kg isotope mass M 18 % ~ 30 % isotope 100 Mo 82 Se or/and 150 Nd T 1/2 (  ) > ln 2  M    T obs N 90 N A A  NEMO-3 SuperNEMO internal contaminations 208 Tl and 214 Bi in the  foil 208 Tl: < 20  Bq/kg 214 Bi: < 300  Bq/kg 208 Tl   Bq/kg if 82 Se: 214 Bi  10  Bq/kg T 1/2 (  ) > 2 x y < 0.3 – 0.9 eV T 1/2 (  ) > (1-2) x y < eV energy resolution (FWHM) 3 MeV efficiency 

30-Jun-2008 R. Saakyan: Ulisse at LSM Workshop. 6 USA MHC INL U Texas Japan U Saga KEK U Osaka France CEN Bordeaux IReS Strasbourg LAL ORSAY LPC Caen LSCE Gif/Yvette UK UCL U Manchester Imperial College Finland U Jyvaskula Russia JINR Dubna ITEP Mosow Kurchatov Institute Ukraine INR Kiev ISMA Kharkov Czech Republic Charles U Praha IEAP Praha Marocco Fes U Slovakia (U. Bratislava) ~ 90 physicists, 12 countries, 27 laboratories Spain U Valencia U Saragossa U Barcelona SuperNEMO Collaboration Poland U Warsaw

30-Jun-2008 R. Saakyan: Ulisse at LSM Workshop. 7 SuperNEMO preliminary design Planar geometry. 20 modules for 100+ kg Top view Side view Source (40 mg/cm 2 ) 12m 2, tracking volume (~2k Geiger channels). calorimeter (600 channels) 5 m 1 m 4 m Total: ~ 40 Geiger channels for tracking ~ 12k PMTs (3k if scintillator bars design) Single model (baseline design)

30-Jun-2008 R. Saakyan: Ulisse at LSM Workshop. 8 Single sub-module with ~5-7 kg of isotope ~20 sub-modules for 100+ kg of isotope surrounded by water shielding

30-Jun-2008 R. Saakyan: Ulisse at LSM Workshop. 9 1,5m 4,1m 7,75m 2,4m 1m 1,5m J.FORGET SuperNEMO general design june 2008

30-Jun-2008 R. Saakyan: Ulisse at LSM Workshop m 10m 12m He storage 15m Radonless air and gaz mixtures production ISO6 workshop Heavy work surface 24,5m 62m 17,5m 46m

30-Jun-2008 R. Saakyan: Ulisse at LSM Workshop. 11 Choice of Isotope Criteria of choice: - High Q  value - Phase space G  -  half-life - natural abundance - enrichment possibilities purification of 4kg of 82 Se underway (INL, US) enrichment of 150 Nd possible 82 Se obtained by centrifugation Impossible for 150 Nd, only laser enrichment

30-Jun-2008 R. Saakyan: Ulisse at LSM Workshop. 12 SuperNEMO simulations Full detector simulation –Event generator GENBB (  + radioactivity) –Geant 4 –Reconstruction Tracks reconstructed from tracker hits and fitted –Cellular automation for track patterns –Kalman filter for fitting Even vertex found in the foil Track matched with calorimeter hits Charge sign measured from curvature Draws heavily from NEMO3 experience Overall efficiency ~30% (conservative scenario: B-field on, module width 1m, reject “double hits” etc..) SNOVA

30-Jun-2008 R. Saakyan: Ulisse at LSM Workshop. 13 SuperNEMO simulations and physics reach Se82Nd150 “Conservative” scenario 82 Se: T 1/2 (  ) =(1-2) yr depending on final mass, background and efficiency  0.06 – 0.1 eV (includes uncertainty in T 1/2 ) – MEDEX’07 NME 150 Nd: T 1/2 (  ) = yr  eV (but deformation not taken into account) Sensitivity

30-Jun-2008 R. Saakyan: Ulisse at LSM Workshop – 2009 Approved in UK, France and Spain. Smaller but vital contributions from US, Russia, Czech Republic, Japan. Main tasks and deliverables –R&D on critical components Calorimeter energy resolution of 4% (FWHM) at 3 MeV Optimisation of tracking detector and construction (robot) Better background rejection (e.g. extra veto counters) Ultra-pure source production and purity control Simulations and geometry optimisation. –Technical Design report in 2010 –Experimental site selection (Frejus, Canfranc, Gran Sasso, Boulby) SuperNEMO Design Study

30-Jun-2008 R. Saakyan: Ulisse at LSM Workshop. 15 Calorimeter R&D Energy resolution is a combination of energy losses in foil and calorimeter  E/E Goal: 7-8%/ √E  4% at 3 MeV ( 82 Se Q  ) Studies: –Material: plastic (PST, PVT) or liquid –Geometry and shape (blocks, bars) –Size –Reflective coating –PMT High QE Ultra-low background Factor of 2 compared to NEMO3!

30-Jun-2008 R. Saakyan: Ulisse at LSM Workshop. 16 Calorimeter R&D. scintillator Hamamatsu high-QE PMT 207 Bi  E/E = 6.5% at 1 MeV  3.8% at 3 MeV Scint. Block in dark box 90 Sr (370 MBq) e - beam & trigger DAQ

30-Jun-2008 R. Saakyan: Ulisse at LSM Workshop. 17 Scint Dimensions (solid) 1 MeV PMT Size and Make 5 2 x 2 cm BC %3in Ham-SBA 9 2 x 2 cm BC %8in Ham-SBA w/ LG 14 2 x 2 cm BC %8in ETL w/ LG 15 2 x 2 cm BC %8in Ham-SBA w/ LG 20 (hex) x 2 cm BC %8in Ham-SBA w/ LG ** 20 2 x 2 cm PST (cast)7.0 %8in Photonis XP1886 ** 20 2 x 10 cm PST (cast)7.7 %8in Photonis XP1886 Solid Scint. Results ** preliminary Calorimeter R&D. Results so far. Baseline design target!

30-Jun-2008 R. Saakyan: Ulisse at LSM Workshop. 18 Calorimeter R&D. Results so far. Liquid Scint. Results Scint Dimensions (liquid) 976 keV PMT Size and Make  7.6 x 5 cm 7.6 %3in Photonis XP5312  7.6 x 10 cm 8.0 %3in Photonis XP5312  8.4 x 9.2 cm 7.3 %5in Photonis XP2412  20.3 x 20 cm 11.3 %8in Photonis XP (hex) x 9.2 cm10.8 %5in ETL 9390

30-Jun-2008 R. Saakyan: Ulisse at LSM Workshop. 19 Calorimeter R&D. Status. 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 Target resolution 7-8% at 1 MeV (~4% FWHM at 3 MeV) reached for individual large baseline design blocks. PMTs –Working closely with manufacturers: Hamamatsu, Photonis, ETL –Real breakthrough in high-QE PMTs from Hamamatsu and Photonis: 43% QE. –Deep involvement in ultra-low background PMT development (especially Photonis) Decision on calorimeter design in early 2009

30-Jun-2008 R. Saakyan: Ulisse at LSM Workshop. 20 Optimize length, wire material and diameter, read-out, gas mixture etc Several 1-cell and two 9-cell prototypes built and tested 90-cell prototype being built Tracker R&D 9-cell prototype in Manchester

30-Jun-2008 R. Saakyan: Ulisse at LSM Workshop. 21 Tracker studies. 1-cell prototypes. 370 cm Plasma propagation times Anode and cathode ring signals from ionization event - Transverse position from electron drift times - Longitudinal position from plasma propagation times - Wire diameter studies - Anode vs cathode rings only readout for longitudinal position reconstruction (anode readout feasible) - Electron drift times measured with laser - Cell diameter studies

30-Jun-2008 R. Saakyan: Ulisse at LSM Workshop. 22 Tracker studies. 9- and 90-cell prototypes. 12 wires per cell 8 wires per cell 9-cell: End-cap design optimized for wiring robot feasible 8-12 wires per cell work Geiger plateau > 200 V Plasma propagation efficiency ~100% 90-cell Will be built and wired by August Tracking efficiency, cross-talk, ageing etc Final SuperNEMO tracker design in early 2009.

30-Jun-2008 R. Saakyan: Ulisse at LSM Workshop. 23 Pair of end fittings Anode wire feed mechanism Clamp mechanism Actuator mechanism Tracker fully automated wiring. Up to ~500,000 wires to be strung, crimped, terminated Wiring robot being developed in collaboration with Mullard Space Science Lab (UCL)

30-Jun-2008 R. Saakyan: Ulisse at LSM Workshop. 24 BiPo detector To measure contaminations of 208 Tl and 214 Bi in source foils before installation in SuperNEMO Goal: ~5kg of foil (12m 2, 40mg/cm 2 ) in one month with a sensitivity of – 208 Tl < 2  Bq/kg – 214 Bi < 10  Bq/kg BiPo-1 to measure scintillator surface contamination Installed and commissioned in Canfranc in October’07 Temporarily relocated to Modane until Canfranc reopens Extrapolated sensitivity from BiPo-1 first results:~1-10  Bq/kg BiPo-2 results expected end Background < 1 event/month!

30-Jun-2008 R. Saakyan: Ulisse at LSM Workshop. 25 SuperNEMO Design Study Schedule Summary NEMO3 Running Running full detector in 2014 Target sensitivity ( eV) in 2016/17 construction of 20 modules Installation Installation at new LSM at new LSM Preparation of new LSM site BiPoinstallation BiPo1Canfranc/LSMBiPoconstruction BiPo Canfranc 1-4 SuperNEMO modules running at Canfranc running at Canfranc SuperNEMO 1 st module construction 2014 

30-Jun-2008 R. Saakyan: Ulisse at LSM Workshop. 26 SuperNEMO: a chance to see a “smoking gun” evidence for 0  and directly disentangle underlying physics mechanism (V+A, Majoron, etc) Design Study addresses most critical issues –Energy resolution –Tracker optimization –Radiopurity Based on design study results full proposal for 100+ kg detector in – 82 Se – baseline, 150 Nd possible. –“Last minute” isotope change if e.g. CUORE sees the signal in 130 Te. Start-up in stages due to modular approach –First module 2010/11 –All 20 modules ~2013 Target sensitivity: meV by 2016/17 Summary