Dark Matter search with EDELWEISS and beyond Gilles Gerbier CEA Saclay – IRFU Rencontres de Moriond- VHEPU march 15 th Expérience pour DEtecter Les Wimps E n SIte Souterrain European Underground Rare Event Calorimeter Array

2 CEA Saclay (IRFU and IRAMIS) CSNSM Orsay (CNRS/IN2P3 + Univ. Paris Sud) IPN Lyon (CNRS/IN2P3 + Univ. Lyon 1) Institut Néel Grenoble (CNRS/INP) LPN Marcoussis (CNRS) Karlsruhe Institute of Technology JINR Dubna Oxford University Sheffield University Karlsruhe The EDELWEISS collaboration 4800 mwe Laboratoire Souterrain de Modane - LSM (Fréjus tunnel) LSM J Gascon/IPNL : spokesman

3 The EDELWEISS-II infrastructure cryostat Polyethylene shield Pb shield Muon Veto Neutron counter 3He detector Innovative dilution cryogenic set-up (18 mK) :  Can host up to 40kg of detectors Shieldings :  Clean room + deradonized air 10 mBq/m3  Active muon veto (>98% coverage)  50-cm PE shield + 20-cm lead shield Other side monitoring detectors:  Radon detector down to few mBq/m 3  He3 neutron detector (thermal neutron monitoring inside shields) sensitivity ~10 -9 n/cm 2 /s  Liquid scintillator neutron counter (study of muon induced neutrons)

4 The EDELWEISS-II infrastructure cryostat Polyethylene shield Pb shield Muon Veto Neutron counter 3He detector Cryogenic installation (18 mK) :  Can host up to 40kg of detectors Shieldings :  Clean room + deradonized air 10 mBq/m3  Active muon veto (>98% coverage)  50-cm PE shield + 20-cm lead shield Other side monitoring detecetors:  Radon detector down to few mBq/m 3  He3 neutron detector (thermal neutron monitoring inside shields) sensitivity ~10 -9 n/cm 2 /s  Liquid scintillator neutron counter (study of muon induced neutrons)

5 Detector principles : 3 parameters to isolate signal Germanium 17 mK Ionization few V/cm Heat measurement (NTD sensor) Discriminating variable between ER and NR « Q » = ionization/recoil energy Neutron calibration (S. Scorza PhD thesis) nuclear recoils (NR) electron recoils (ER) Fiducial volume A: +4 V B: -1.5V C: -4 V D: +1.5V = Ionization « VETO » = > « Surface/beta » identification : if non zero, reject event NB : idea first presented by CDMS group at LTD Recent: ID400 Old : GeNTD Fiducial annular electrodes Guard planar electrode All planar electrode VETO B VETO D

6 Detector principles : 3 parameters to isolate signal Germanium 17 mK Ionization few V/cm Heat measurement (NTD sensor) Discriminating variable= « Q » = ionization/recoil energy Neutron calibration (S. Scorza PhD thesis) nuclear recoils (NR) electron recoils (ER) Fiducial volume A: +4 V B: -1.5V C: -4 V D: +1.5V Surface identification = Ionization VETO If non zero, reject event New : ID400 Old : GeNT Fiducial annular electrodes Guard planar electrode All planar electrode 1 evt 6x Pb 6x Bi 6x Po

7 EDELWEISS II limits (2011) and EDELWEISS -CDMS combined analysis 10 ID detectors of 400 g operated during ~ 1 y CDMS has same target and same sensitivity Simple merger of data sets chosen prior to any analysis. EDW II: 384 kg.d, [ keV], 5 evts CDMS: ~379 kg.d, [~10-100keV], 4 evts => ~50% gain at high WIMP masses. NB : CDMS decides on an ID-inspired design for the electrodes of its future detectors. Phys. Rev. D 84, (2011). made with dmtools “WIMP safe” mass concept ! Check PDG “Dark Matter review” by Drees&Gerbier

Recent EDELWEISS low mass analysis Realization that, despite being tuned for M WIMP ~100 GeV, EDELWEISS-II had significant efficiency down to 5 keV recoil Significant background rejection with ID electrodes down to low energy wth subset of data => significant improvement down to 7 GeV WIMP mass Resolutions are improving with new electronics (FWHM 900 eV -> 650 eV for ionization, > <1 keV for heat) 500 eV achieved in tests (HEMT R&D to go down to 300 eV?) 25 octobre 2012EDELWEISS-III report to CSIN2P3 EDW II LE PRD 86 (2012) R 10 GeV WIMP – ID3

9 Expected pattern f(E,t) for given orientation angle of crystal vs sun direction NB : electron recoils Searching for axions Detection/production by Primakov effect g a  Solar axions  ->  +a >a+  ->  f(E, t,  Bragg diff Preliminary Single detector Edelweiss II PhD Work of T de Boissiere Other constraints on g ae m a currently studied

10 EDELWEISS-III : few pb 60 Gev Detectors 40 FID800 detectors 24 kg fiducial, installed 2013 (factor 15 wrt before) 2 NTD sensors/detector Current EDW-II setup : major upgrade new cabling, cold electronics new cryogenics (lower  phonic noise) new internal PE shielding replacement of thermal shields with lower activity Cu => Expect lower thresholds, lower background (  and n), and redondancy Program (1.6 M€) funded : upgrade finished at 95 %, cool down on going (march 2013) with 15 detectors Results by 2014

11 EDELWEISS III : new detectors FID800 Fid mass *4 wrt to ID400 No NR event in  calibration Expected to be and indeed better than IDs ! FID800(  ) ID400 (  ) Fiducial mass ~640g All annular electrodes

Coverage of low-mass region with 4 FID detectors with 300 eV FWHM resolutions (1200 kgd), 3 keV Er threshold thanks to new HEMT replacing JFET 1 evt, 10 keV thresh kg.j EDELWEISS-III : improved 5-15 GeV sensitivity HEMT R&D ongoing

13 EURECA Status 2013 EDELWEISS+CRESST +others (19) CDR written Baseline : 2 phases: 150 kg then1 t Choice of balance Ge / CaWO4 to be optmised vs physics reach at time t Basic features  Favored site : LSM : deepest in Europe  Large water active shield  7 mK base temp, « scalable cryogenics » see P Camus  Flexible design for different detectors  Tower design : fully integrated, 7mk- 300k see H Kraus No common official proposal submitted yet Strong will to make common project with S-CDMS

New Actual 50 m Last status jan 2013  Excavation of the extension 2014 or  In operation in 2016/2017.  Detailed studies funded by Savoie departement and Rhone-Alpes Region  Agreement from Ministery and CNRS for the project  Funding in progress (85% already obtained CNRS, Region Rhone-Alpes, FEDER funds)  Technical discussion in progress France Italy LSM underground lab extension New

15 Summary, prospects