TeV Particle Astrophysics II - Madison August 30, 2006 Elena Aprile, Columbia University Future of Dark Matter Direct Detection (with Cryogenic Noble Liquids) Elena Aprile Physics Department and Columbia Astrophysics Laboratory Columbia University TeV Particle Astrophysics II - Madison August 30, 2006 Elena Aprile, Columbia University Direct Detection Methods/Experiments DAMA/LIBRA EDELWEISS CDMS XENON, XMASS-II, ZEPLIN2, ZEPLIN3, WARP, ArDM CRESST ZEPLIN1 XMASS Mini-CLEAN Double Phase (Xe, Ar) TeV Particle Astrophysics II - Madison August 30, 2006 Elena Aprile, Columbia University Goal: Cover Supersymmetry World-best limit today CDMS II 2007 SuperCDMS Phase C 1000 kg of Ge SuperCDMS 25kg 25 kg of Ge 2011 SuperCDMS Phase B 150 kg of Ge ZEPLIN I EDELWEISS ZEPLIN 2 XENON 10 DAMA cm cm cm 2 TeV Particle Astrophysics II - Madison August 30, 2006 Elena Aprile, Columbia University Cryogenic Noble Liquids Suitable materials for detection of ionizing tracks: u Dense, homogeneous, target and also detector u Do not attach electrons u High electron mobility (except neon in some conditions) u Commercially easy to obtain and to purify u Inert, not flammable, very good dielectrics Element Liquid Density ( /cm 3 ) Energy loss dE/dx (MeV/cm) Radiation length X 0 (cm) Collision length (cm) Boiling 1 bar (K) Electron mobility (cm 2 /Vs) Neon high&low Argon Krypton Xenon $ $$ $$$ Cost From C. Rubbia TeV Particle Astrophysics II - Madison August 30, 2006 Elena Aprile, Columbia University LXe & LAr for Dark Matter Direct Detection Liquid Xenon Large A (~ 131): good SI case ( ~ A 2 ) but low threshold a must Presence of 129 Xe (26.4%) and 131 Xe (21.2.4%) good for SD u No long-lived radioisotopes. Kr85 fraction to ppt level proven u Excellent stopping power for compact, self-shielding geometry u Easy cryogenics at -100 C u Efficient scintillator ( 80% of NaI) with fast time response u Background Discrimination Methods: Charge and Light ratio plus 3D event localization Liquid Argon u A=40 good for higher mass WIMPs u No odd isotopes for SD u 39 Ar at ~1 Bq/kg require rejection > 10 7 u Not so Easy Cryogenics at 186 C but easier to purify u Larger volumes required to compensate low Z and density larger size cryostat and shielding (cost) but raw Ar is cheap u Background Discrimination Methods: Charge and Light ratio plus 3D event localization plus Light PSD Integrated Rates Above Threshold Differential Rates TeV Particle Astrophysics II - Madison August 30, 2006 Elena Aprile, Columbia University Dual Phase TPCs with Simultaneous Charge and Light Readout: XENON ZEPLIN WARP ArDM XMASS (Scintillating LXe Calorimeter kg Solar Neutrino/Dark Matter Kamioka See Y.Koshio talk at XMASSII (Double Phase LXe-15 kg) Dark Matter Kamioka See S.Suzuki talk at Mini-CLEAN/DEAP ( Scintillating LNe/LAr Calorimeter - 100Kg) Solar Neutrino/Dark Matter SNOLAB/Homestake? See D.McKinsey talk atSingle Phase LXe or LAr Scintillating Detectors: recent talks TeV Particle Astrophysics II - Madison August 30, 2006 Elena Aprile, Columbia University Dual Phase TPC Principle of Operation WIMP or Neutron nuclear recoil electron recoil Gamma or Electron TeV Particle Astrophysics II - Madison August 30, 2006 Elena Aprile, Columbia University The XENON Experiment: Overview 1 ton target distributed in TPC modules each with ~ 100kg active Xe, viewed by low activity VUV PMTs directly coupled to liquid/gas. Event-by-event discrimination of nuclear recoils from electron recoils (>99%) down to 16 keVr from a) simultaneous detection of scintillation (S1) and ionization (via proportional scintillation S2) and b) 3D event localization with millimeter resolution. Phase 1 (XENON10) : TPC prototype with 15 kg active target. Operating underground (Gran Sasso) with passive gamma/neutron shield. ~50kg-day exposure as of today! 1 st physics results soon. Funded by NSF and DOE. Phase 2 (XENON100) : design studies started, assuming present location and shield. Final design to be determined by XENON10 performance. Goal is to have XENON100 taking physics data by Phase 3 (XENON1T): to be defined by results from XENON Phase 2 and other experiments worldwide TeV Particle Astrophysics II - Madison August 30, 2006 Elena Aprile, Columbia University XENON: Dual-Phase XeTPC with 3D Event Imaging Background Discrimination simultaneous detection of scintillation (S1) and ionization (via proportional scintillation S2) signals down to 16 keV nuclear recoil energy 3D event localization with millimeter spatial resolution XENON Phased Program Modular design: 1 ton in ten 100 kg modules XENON10 Phase: TPC module with 15 kg active target moved underground (Gran Sasso Laboratory) in March 06. Shield construction completed July 06. Dark Matter Search now ongoing. Funded by NSF and DOE XENON100 Phase: design/construction in FY07/08 (2M$ construction). Commission and start underground operation in 2008. TeV Particle Astrophysics II - Madison August 30, 2006 Elena Aprile, Columbia University XENON Dark Matter Goals SUSY Theory Models Dark Matter Data Plotter CDMS II goal SUSY Theory Models XENON10 ( ): 10 kg target ~2 events/10kg/month XENON100 ( ): 100 kg target ~2 events/100kg/month XENON-1T (>2010): 1 ton target ~1 event/1 tonne/month TeV Particle Astrophysics II - Madison August 30, 2006 Elena Aprile, Columbia University Columbia University Elena Aprile (PI), Karl-Ludwig Giboni, Maria Elena Monzani,, Guillaume Plante*, and Masaki Yamashita Brown University Richard Gaitskell, Simon Fiorucci, Peter Sorensen*, Luiz DeViveiros* Case Western Reserve University Tom Shut t, Eric Dahl*, John Kwong* and Alexander Bolozdynya Lawrence Livermore National Laboratory Adam Bernstein, Norm Madden and Celeste Winant Rice University Uwe Oberlack, Roman Gomez* and Peter Shagin Yale University Daniel McKinsey, Richard Hasty, Angel Manzur*, Kaixuan Ni RWTH Aachen University, Germany Laura Baudis, Jesse Angle*, Joerg Orboeck, Aaron Manalaysay* Laboratori Nazionali del Gran Sasso, Italy Francesco Arneodo, Alfredo Ferella* University of Coimbra, Portugal Jose Matias Lopes, Luis Coelho*, Luis Fernandes, Joaquim Santos The XENON10 Collaboration TeV Particle Astrophysics II - Madison August 30, 2006 Elena Aprile, Columbia University 9 young PostDoc scientists- 11 graduate students Many of them at LNGS TeV Particle Astrophysics II - Madison August 30, 2006 Elena Aprile, Columbia University Ionization and Scintillation in Noble Liquids I/S (electron) >> I/S (non relativistic particle) Alpha scintillation electron scintillation Electron charge Alpha charge Electric Field (kV/cm) L/L0 or Q/Q0 (%) Recombination Excitation (Xe*) Ionization (Xe +, e) Xe 2 * ( 1 , 3 ) 2Xe+h (175 nm) FastSlow TeV Particle Astrophysics II - Madison August 30, 2006 Elena Aprile, Columbia University Recent Highlights from XENON R&D Scintillation Efficiency of Nuclear Recoils in LXe Aprile et al., Phys. Rev. D 72 (2005) Ionization Yield of Nuclear Recoils in LXe Aprile et al., accepted in PRL (2006) TeV Particle Astrophysics II - Madison August 30, 2006 Elena Aprile, Columbia University Case ELASTIC Neutron Recoils INELASTIC 129Xe 40 keV + NR INELASTIC 131Xe 80 keV + NR 137Cs source Upper edge -saturation in S2 AmBe n-source Neutron ELASTIC Recoil 5 keVee energy threshold = 10 keV nuclear recoil Columbia+Brown Nuclear and Electron Recoils Discrimination TeV Particle Astrophysics II - Madison August 30, 2006 Elena Aprile, Columbia University 1 square PMTs: Hamamatsu R Al Metal Channel, compact (3.5cm long); QE>20% Background Rejection by S2/S1 and 3D Event Localization Neutron Elastic Recoil 40 keV Inelastic ( 129 Xe) + NR 80 keV Inelastic ( 131 Xe) 110 keV inelastic ( 19 F) + NR Neutron Elastic Recoil 40 keV Inelastic ( 129 Xe) + NR 80 keV Inelastic ( 131 Xe) + NR Edge Events reduced by 5 mm radial cut: XENON3 TPC exposed to 2.5 MeV neutrons TeV Particle Astrophysics II - Madison August 30, 2006 Elena Aprile, Columbia University Pulse tube cryocooler 15 kg LXe XENON10 Vacuum Cryostat Re-condenser TPC active area ~ 20 cm diameter; LXe drift gap= 15 cm 22 kg (15 kg active) Xe mass 1kV/cm drift field - Custom designed HV feedthrough. SS vessel and vacuum cryostat. 89 PMTs (R AL): 48 in GXe and 41 in LXe Light response (S1) : 2 pe/keV at 1 kV/cm Pulse Tube Refrigerator for stable operation at 95C. TeV Particle Astrophysics II - Madison August 30, 2006 Elena Aprile, Columbia University XENON10: TPC Details Bottom PMT Array, PTFE Vessel Top PMT Array PMT Base (LLNL) LN Cooling Loop Level Meters (Yale) Grids, Tilmeters (Case) HV- FT TeV Particle Astrophysics II - Madison August 30, 2006 Elena Aprile, Columbia University XENON10 underground at the Gran Sasso Laboratory March 2006: XENON10 shipped from Nevis Labs to LNGS and commissioning starts underground. Detector is tested/calibrated in temporary location while passive shield is designed/built. Move detector in shield in July XENON10 filled with low Kr-Xe; DM Search starts August 2006 TeV Particle Astrophysics II - Madison August 30, 2006 Elena Aprile, Columbia University XENON10 Shield 3500 mm 2410 mm 200 mm 40 ton Pb ton Poly: ( 210 Pb 30 Bq/kg) inner Pb & ( 210 Pb 500 Bq/kg) Outer Pb Inner Cavity for Detector: 90 cm x 90 cm x1.1 m (H) TeV Particle Astrophysics II - Madison August 30, 2006 Elena Aprile, Columbia University : XENON10 : 3D Event Localization Events are localized in X,Y,Z: 1)Z position determined by drift time, time b/w S1 and S2 2)X&Y positions reconstructed from S2 detected by top 48 PMTs (in gas), based on a simulated map. S2S1 3D event localization is in good agreement with MC (data from a Cs-137 calibration run). Min-Chisq position reconstruction for an edge event. TeV Particle Astrophysics II - Madison August 30, 2006 Elena Aprile, Columbia University XENON10 MC Estimated Background Rate Original XENON10 Goal Electron Recoils 10 kg LXe Radius (10 cm) - Depth (15 cm) Event Rates (log(/keV/kg/day)) In XENON10 Stainless Steel Cryostat & PMTs (background in 5-25 keVee) [Dominant BGs] u Stainless: MC using value of 100 mBq/kg 60Co u PMTs /