HPGe γ谱仪γ能谱高能端探测效率校准

Efficiency Calibration over the High Energy Range of a HPGe γ Spectrometer

γ能谱法分析压水堆一回路水样品过程中,为获取HPGeγ谱仪高能端的探测效率曲线,选择226Ra和232Th制成土壤标准源,利用226Ra子体214Bi和232Th子体208Tl中几条发射概率较高的!射线进行谱仪探测效率校准。获得的效率曲线经过自吸收修正和符合相加修正,得到了Φ70 mm×30 mm水溶液源高能端(1.120 MeV<Eγ<2.754 MeV)的效率曲线。

In the process of analyzing the sample in the primary coolant of PWR using γ spectrometry,in order to obtain the efficiency curve over the high energy range of HPGe γ spectrometer,226 Ra and232 Th were selected to produce the soil calibration source, and then several ! rays with high emission probabilities in226 Ra＇s decay products and232 Th＇s decay products were employed to perform efficiency calibration. The efficiency curve was corrected by self-absorption and true coincidence summing,this paper obtained the efficiency curve of a Φ70 mm×30 mm aqueous calibration source over the high energy range（ 1 120 - 2 754 keV）.