探测器自身放射性本底 CsI crystal CsI Powder

脉冲形状甄别 PSD

Pulse Shape Discrimination

Quenching factor (ionization yield  energy)

沟道效应

DAMA/LIBRA  NaI(Tl) Scintillator at Gran Sasso : total 0.82 ton-year data  Observe annual modulation in the 2- 6 keV single-hit signal band, total 11 cycles, > 8    Reject gamma by PSD  No modulations at higher energy & for multiple-hits December 30 km/s ~ 232 km/s 60 ° June 30 km/s NaI 晶体实验

 Annual Modulation in single hit at 2-6 keV  No Modulation for multiple hits at 2-6 keV  No Modulation for single hit above 6 keV  multiple-hits residual rate (green points) vs single-hit residual rate (red points) Single-Hit Power Spectrum

 Single Hit 2-6 keV Signal Region  DAMA/NaI (7 years) + DAMA/LIBRA (4 years)  Total exposure: kg  day = 0.82 ton  yr

HP Ge detector / PC Ge detector High efficiency High resolution Large mass Pure material Low noise/ Low threshold

Semiconductor detector materials HPGe 的体积，质量最大 ( Kg)

HPGe 的能量分辨最好

三种 HPGe 探测器 planar Coaxial detector VbVb p (n) p + (n + ) n + (p + ) S0S0 S1S1 p PCGe detector

反冲电子或核的次级电子空穴的收集形成信号

- V Q t Charge induction + +

- V Q t Charge induction

- V Q t Charge induction

Planar detector with perfect charge transport - V Q ind t