宽能高纯锗γ能谱仪环境样品探测效率测试研究  

Study on Detection Efficiency of Broad Energy HPGe γ Spectrometers for Environmental Sample

作　　者：肖李翔 李少婷 周肖肖 余晫 张雨晨 XIA Lixiang;LI Shaoting;ZHOU Xiaoxiao;YU Zhuo;ZHANG Yuchen(Nuclear and Radiation Environmental Monitoring Center of Hubei Province,Wuhan 430070)

机构地区：[1]湖北省核与辐射环境监测技术中心,湖北武汉430070

出　　处：《核电子学与探测技术》2024年第6期1043-1052,共10页Nuclear Electronics & Detection Technology

基　　金：生态环境部全国辐射环境监测项目(JC202318)。

摘　　要：对两种宽能高纯锗γ能谱仪的性能做了测试,研究了不同标准源、距离探测器不同距离以及死时间对两种宽能型高纯锗γ能谱仪探测效率的影响。测试结果表明:两种宽能高纯锗γ能谱仪能量刻度曲线的R^(2)值均为1,线性良好;能量小于165 keV时,两种探测器探测效率明显优于传统P型探测器;样品直径和厚度差异对探测效率影响显著;刻度源距离探测器5 cm和10 cm时,γ能量<391 keV时BE6530的探测效率高于GEM-C65,γ能量>391 keV时BE6530的探测效率低于GEM-C65,测试结果可为测量不同能量选择测试仪器提供参考;扩展了宽能高纯锗γ谱仪活度较高样品的测量范围,可以用修正公式对死时间百分数为50%的计数率结果进行修正,修正后,环境样品在两台仪器的测值相对偏差明显降低。The performance of two broad energy Germanium types HPGe γ spectrometers was tested in this work.The impact of different standard sources,detector distances,and dead times on the detection efficiency of the two broad energy Germanium types HPGeγspectrometers was explored.The test results showed that the R^(2) values of the energy calibration curves for the two broad energy Germanium types HPGeγspectrometers were both 1,indicating good linearity.When the energy was less than 165 keV,the detection efficiency of the two detectors was significantly better than that of traditional P-type detector,and the differences in sample diameter and thickness had a significant impact on the detectors efficiency.When the calibration source was 5 cm and 10 cm away from the detector and the energy was less than 391 keV,the detection efficiency of the BE6530 was higher than that of the GEM-C65.Conversely,when the energy was greater than 391 keV,the result was reversed.In addition,this study expanded the measurement range for samples with high activity using the HPGe γ spectrometers.By using a correction formula to correct the counting rate results with a dead time of 50%,it showed that the relative deviation of the corrected environmental samples in the two spectrometers was significantly reduced.

关 键 词：宽能 高纯锗γ能谱仪 效率 测试 死时间修正 

分 类 号：TL817[核科学技术—核技术及应用]