探测器自身放射性本底

1、探测器自身放射性本底CsI crystalCsI Powder21/22/1111ttteaea脉冲形状甄别脉冲形状甄别 PSDPulse Shape DiscriminationiiiAtAtQuenching factor (ionization yield energy)thReeREoutputeeoutputRREeRREELLLL沟道效应DAMA/LIBRA NaI(Tl) Scintillator at Gran Sasso : total 0.82 ton-year dataObserve annual modulation in the 2-6 keV single-hit

2、signal band, total 11 cycles, 8s s Reject gamma by PSDNo modulations at higher energy & for multiple-hits December30 km/s 232 km/s60 June30 km/sNaI晶体晶体实验实验multiple-hits residual rate (green points) vs single-hit residual rate (red points) Single-Hit Power Spectrum Single Hit 2-6 keV Signal Regio

3、n DAMA/NaI (7 years) + DAMA/LIBRA (4 years) Total exposure: 300555 kg day = 0.82 ton yr表 4-1： 各种常用闪烁体的性能比较 材料 最强发光 波长(nm) 发光衰减时间 折射率 密度 (g/cm3) 光产额 (光子/MeV) NaI(Tl) 410 0.23s 1.85 3.67 42000 CsI(Tl) 565 1.0s 1.79 4.51 55000 ZnS(Ag) 450 0.2s 2.4 4.09 8Li(Eu) 480 1.4s 1.95 4.08 Li 玻璃 395.9 75ns 1.53 2

4、.5 BGO 480 0.3s 2.15 7.13 8900 BaF2 310 6s/ 0.6ns 1.56 4.89 9900 CWO 500 5s 2.3 7.9 19700 蒽 447 30ns 1.62 1.25 芪 410 4.5ns 1.63 1.16 液体闪烁体 420 2.44ns 1.52 0.9 HP Ge detector / PC Ge detectorHigh efficiencyHigh resolution Large massPure materialLow noise/ Low threshold ?10-710-610-610-510-3h lifetime

5、 (s) h?10-810-510-610-610-3e lifetime (s) e70040010100440,000h mobility h(cm2/Vs)110080001000110010040,000e mobility e(cm2/Vs)0.140.090.190.08Fano factor4.24.64.44.22.97e-h pair creation energy (eV)1.61.431.571.502.130.74Band gap (eV)13, 5131, 3348, 30, 5248, 5280, 5332Atomic numberAlSbGaAsCdZnTeCdT

6、eHgI2Ge (77K)Material?10-710-610-610-510-3h lifetime (s) h?10-810-510-610-610-3e lifetime (s) e70040010100440,000h mobility h(cm2/Vs)110080001000110010040,000e mobility e(cm2/Vs)0.140.090.190.08Fano factor4.24.64.44.22.97e-h pair creation energy (eV)1.61.431.571.502.130.74Band gap (eV)13, 5131, 3348

7、, 30, 5248, 5280, 5332Atomic numberAlSbGaAsCdZnTeCdTeHgI2Ge (77K)MaterialSemiconductor detector materialsHPGeHPGe 的体积，质量最大的体积，质量最大( Kg)( Kg)HPGeHPGe 的能量分辨最好的能量分辨最好三种三种HPGeHPGe探测器探测器planarCoaxial detectorVbp (n)p+ (n+)n+ (p+)S0S1pPCGe detector反冲电子或核的次级电子空穴的收集形成信号反冲电子或核的次级电子空穴的收集形成信号- VQtCharge induct