应用蒙特卡罗方法模拟HPGeγ谱仪的体源探测效率

Simulating Calculation for the HPGe γ-spectrometer Detection Efficiency of a Volume Source Using Monte Carlo Method

采用蒙特卡罗方法模拟计算了HPGeγ谱仪对标准样品体源的全能峰探测效率;然后通过实验测量获得标准样品体源各特征能量γ光子的全能峰净计数,并结合模拟得到的全能峰探测效率计算出标准样品体源中天然放射性核素的比活度,计算结果与标称值的相对偏差在±3%以内,符合较好。

Full -energy peak detection efficiencies of HPGe γ-spectrometer for a standard volume source （Φ7.5 cm ×7.0 cm） have been calculated by Monte Carlo simulations , and then, we obtained the radionu-clides specific activity in the standard volume source , using the simulated detection efficiencies and the net counts of the full -energy peak from γspectrum by experimental measurements .The calculated results were compared with the nominal value , the relative deviation is within ±3%.