介绍了配置于新型γ能谱仪的CsI(Tl)闪烁探测器的读出电路设计。输入缓冲级采用折叠嵌位电路,改善了系统频率特性并提高了输入阻抗;放大级采用自举电路,改善了系统动态性能并提高了开环增益;输出级采用电流源负载电路,改善了输出信号的线性度并增强了系统的稳定性。实验表明:读出电路噪声为51.08 f C+1.97 f C/p F,时间漂移为0.112%,探头对137Cs源γ射线的输出信号信噪比可达23:1,能量分辨率可达4.98%。
The paper introduces the design of readout circuit for CsI ( Tl ) detector of the new γ spectrometry. The input buffer adopts folding - clamp circuit improving the frequency characteristic of the system and increasing the input impedance, the amplifier stage adopts bootstrap circuit improving dynamic performance of the system and increasing the open - loop gain, the output stage adopts current source load circuit improving the linearity of the output signals and enhancing the stability of the system. The experimental results show that the noise is 51.08fC + 1.97fC/pF and the time - drift is 0.112% for the readout circuit, the SNR of the output signal is 23 : 1 and the energy resolution is 4.98 % for the probe.