为更好服务于环境辐射监测,通过标准放射点源241Am、133Ba、60Co、137Cs、152Eu对平面型HPGe探测器进行标定,分别获得不同特征能量下的探测效率、半高宽、道址等数据。数据处理后得到能量-道址函数、FWHM能量刻度函数、能量与探测效率关系,同时求得能量分辨率为1.58keV(60Co,1.33MeV)。通过对比发现,利用CT技术建立的MC模型更加可靠、高效。通过修正上、下死层厚度依次分段对模型探测效率进行校正,得到整体探测效率相对误差在5%以内,与实验结果符合较好。
Abstract
In order to better serve environmental radiation monitoring, the planer HPGe spectrometer is calibrated by standard radioactive point sources 241Am, 133Ba, 60Co, 137Cs, 152Eu. And the detection efficiency, half height full width, channel address and other data under different energy are obtained respectively. After data processing, the function of energy-channel, function of FWHM-energy scale, relationship of energy and detection efficiency are obtained. At the same time, the energy resolution is 1.58keV (60Co, 1.33Mev). It is found that the MC model established by CT technology is more reliable and efficient. At the same time, the detection efficiency of the model is corrected by the upper dead layer and the bottom dead layer thickness in turn, and the relative error of the overall detection efficiency is within 5%, which is in good agreement with the actual experimental results.
关键词
计量学 /
辐射监测 /
HPGe探测器 /
能量刻度 /
MC模拟 /
死层厚度
Key words
metrology /
radiation monitoring /
HPGe detector /
energy calibration;MC simulation /
dead layer thickness
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基金
国家重点研发计划(2017YFF0205101)
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