HPGe探测器探测效率对γ能量及其探测距离的相关性研究

Study on the Effect of γ- energy and Detection Distance on Detection Efficiency of HPGe- Spectrometer

为了探究高纯锗谱仪探测效率与γ能量和探测距离的普适函数关系,本工作利用标准源133Ba、137Cs和60Co,刻度了探测器在高能段(E>160ke V)的效率曲线;并通过调节探测器与标准源的距离,研究了效率曲线与探测距离的变化关系;最后通过拟合所有实验测量点,得到了普适函数关系式。为减小统计误差,各特征γ的全能峰计数大于2.0×105;同时利用了强源干扰法对较大死时间数据进行了修正。该结果可为开展大规模非标样品的实验测量和体样本探测效率的模拟计算提供参考。

In order to investigate the effect of γ-energy and detection distance on the detection efficiency of HPGe-γspectrometer, this work calibrated the detection efficiency in high energy region （ Eγ〉160 keV） at different detection distances （10 mm 〈50 mm〈0.5 mm） by using the standard sources 133 Ba, 137 Cs and 60 Co.The detection efficiency was found to be a uniform function ofγ-energy and detection distance.In order to minimize the statistical error,the counts of full-energy peaks were greater than 2.0 ×10^5 ,meanwhile the strong-source interference method was used to correct the large dead-time data.This result would facili-tate the experimental measurements of large-scale non-standard samples and the simulation of detection effi-ciency for body sample.