360 likes | 375 Views
Particle detection with liquid xenon. Tugdual OGER Subatech. Liquid Xenon. High atomic number (54) + high density (~3 g/cm 3 ) Efficient to stop penetrating radiation Can provide a good shield. No long lived isotopes Small W-value (15.6 eV) Sensitive for low energy particle detection
E N D
Particle detection with liquid xenon Tugdual OGER Subatech
Liquid Xenon • High atomic number (54) + high density (~3 g/cm3) • Efficient to stop penetrating radiation • Can provide a good shield. • No long lived isotopes • Small W-value (15.6 eV) • Sensitive for low energy particle detection • Fast scintillation light decay time (2.2 ns) • Can help locate the interaction • “easy” cryogenics @ -100 °C • Homogeneous (liquid) • Detector structure can be simplified • Scalable to higher masses Tugdual OGER
Direct search of dark matter with Liquid Xenon Data analyses of 2010 : 48 kg x 100.9 days It’s the most performing experiment searching for dark matter and it’s staring to explore the predictions from WIMP SUSY models: Spin Independent Dark Matter → σ= 7·10-45 cm2 at 50 GeV/c2 Phys. Rev. Lett. 107, 131302 (2011) Phys. Rev. D 84, 061101 (2011) Phys. Rev. D 84, 052003 (2011) With 2011-12 data, sensitivity will improve even more : more statistics (aiming for >200 days more than for 2010), less 85Kr contamination (~ a factor 5), better purity, lower thresholds, more calibration data Xenon10 (2007) 5.4 kg x 58.6 days 5·10-44 cm2 Xenon100 (2010) 40 kg x 11.2 days 3.4·10-44 cm2 Xenon100 (2011) 48 kg x 100.9 days 7.0·10-45 cm2 Xenon1T approved at LNGS (hall B) Xenon100 (2012) aimed sensitivity 2·10-45 cm2 Xenon1T (2014/15) 1000 kg x 1 year O(10-47) cm2 DARWIN Multi-ton LXe / LAr Tugdual OGER
The Compton telescope principle θ E1, x1, y1, z1 E2, x2, y2, z2 Tugdual OGER
The 3 imaging • Promising GEANT4 simulation results obtained with : • 500 µm spatial resolution • low noise (~200 e-) • 2.3% energy resolution at 1 MeV Strong requirements on instruments E0 β+- emitter : 44Sc Production research at Tugdual OGER
The XEMIS cryogenic device XEnon Medical Imaging System Purification circuit Pulse Tube Refrigerator Cryostat Tugdual OGER
Xenon liquefaction by using a pulse tube cryocooler -114°C @ 1bar -110°C @ 1bar T = 4°C Cooling power up to ~200W @165K Tugdual OGER
Insulation of the cryogenic system Multilayer insulation Dynamic vacuum chamber Total system thermal leak ~40 W Tugdual OGER
The circulation system Purification rate : 0.5 liter/min of GXe Tugdual OGER
Removing impurities with a getter filter Tugdual OGER
Rescue system Rescue generating set Pneumatic valve open for P>1.78 bars UPS Bursting disc Mechanical breaking for P>2.0 bars Rescue tank, 4m3 Tugdual OGER
Storage system Cryo-pumpage operation : It takes 5 hours for a complete recovering GXe 100 L bottles P >50 bars Tugdual OGER
A liquid xenon TPC Liquid xenon Photomultiplier Cathode Scintillation signal collection : Information on t0 UV + Ionisation signal collection : Information on t1, E, x et y Field rings = Interaction 3D position : x, y et z = (t1 – t0)·vdrift And deposit energy : E Micromesh Segmented anode Tugdual OGER
Many ways for using the ionization signal Immerged micromeshes XEMIS Immerged wires LXeGRIT Double phase detectorsXENON, ZEPLIN, LUX Tugdual OGER
The XEMIS TPC PMT Hamamatsu Micromegas Grid(not visible) Field rings 2.54cm 12 cm 16 channelsIdef-X FEE Noise level: ~ 100 e- Segmented anode Tugdual OGER
Low-noise front-end electronic Segmented anode Flat - connectors Kapton flat cable Noise on central pads ~100 e- @171 K Lowest electronic noise measured in LXe IDEF-X AsicsDeveloped for CdTe @ IrFU Tugdual OGER
Drift velocity measurement • Accurate drift time measurement: • σ ~150 ns T = 165 K T = 171 K T = 165 K Constant Fraction Discriminator principle: CFD time Tugdual OGER
Electron attenuation Tugdual OGER
Electron attenuation correction Signal attenuation due to electronegative impurities: S = 1.746 ± 0.006 V Z axis S0 = 1.7623 ± 0.0015 V @511 keV λ = 19.52 ± 0.16 cm S = 1.130 ± 0.004 V Tugdual OGER
Electron attenuation length evolution Tugdual OGER
Energy resolution @ 511 keV Tugdual OGER
That’s all Thank you Tugdual OGER
Detection of xenon signals Use of both signals : XENON, EXO, LXeGrite, XEMIS, LUX, ZEPLIN Two signals in competition : ionization and scintillation Use of scintillation only : MEG, XMASS Tugdual OGER
Cas réaliste FWHM = 1.3 cm Considère : parcours du positron associé au 44Sc, émission isotrope Micro-TEP avec xyz = 1 mm, Télescope Compton :sE = 5.9 % @ 1 MeV (FWHM), bruit électronique: 200 e-, xy = 1 mm z= 100 µm Résolution de 1.3 cm le long de la LOR Point de départ de l’étude de faisabilité : 2006 Tugdual OGER
Apparatus ― Time projection chamber 12 cm 1kV/cm 50 m 80kV/cm PMT Hamamatsu Field rings Micromegas Grid(not viewable) 2.54cm 12 cm 16 channelsIdef-X FEE Noise level: ~ 100 e- Segmented anode Tugdual OGER
Le circuit de liquéfaction Tugdual OGER
The Time Projection Chamber Scintillation t0 + Ionisation t1, E, x, y Hamamatsu PMT = 3D position : x, y, z = vdrift(t1 –t0)and energy E Field rings Height : 12 cm 2.56 cm IDeF-X FEE Micromegas grid Segmented anode Tugdual OGER
Nettoyage et assemblage de la zone active en salle propre Tugdual OGER
FE Electronics, les premières mesures de bruit à température ambiante Flat - connectors Kapton feed-through At room temperature, Noise : 125 e- + 4.46 e-/pF Noise ~ 200-300 e- targeted on anode with liquid xenon Tugdual OGER
Quelle électronique FE pour l’anode segmentée ? Segmented anode IDEF-X Asics Flat - connectors IDEF-X : ASIC développé pour CdTe par le service de micro-électronique de l’IrFU Tugdual OGER
Active zone : IDeF-X Kapton flat cable Signal outputs Polarisation circuit IDeF-X Tugdual OGER
FEE characterization 16 channels for 16 pads Noise on central pads ~100 e- @171 K Best electronic noise measured in LXe Only hits located in red region are used for the analysis. Tugdual OGER
511 keV gammas acquisition Field rings Anode µgrid Collimator PMT PMT CsI crystal 22Na source : - β+ (545 keV) - (1.257 MeV) Liquid xenon Tugdual OGER
Impurities concentration evolution Tugdual OGER
511 keV absorption in LXe (NIST : 3,4 cm) Tugdual OGER