不确定度评价方法在高纯锗探测器参数修正中的应用

Application of uncertainty evaluation method in parameter correction of high-purity germanium detector

摘要:

将统计性不确定度评价方法应用到高纯锗(HPGe)探测器参数的标定和修正工作中. 结合蒙特卡洛模拟和统计性不确定度评价方法，分析探测器参数在探测效率模拟结果中的相对重要性，对重要参数同时进行多次简单蒙卡抽样，模拟计算探测器对多空间点多γ源的探测效率，找出真实效率与模拟效率的最小偏差，即能确定最佳探测器参数. 结果表明，此方法修正探测器参数后，对60Co，137Cs， 241Am源在标定点的模拟效率与真实效率相对误差均小于0.5%，在3个验证点的模拟效率与真实效率相对误差均小于0.5%.

Abstract:

In view of the defect of commonly used method for correcting the parameters of high-purity germanium (HPGe) detector, a new correction method based on statistical uncertainty analysis and Monte Carlo simulation is proposed. The relative importance of the parameters of HPGe detector in the simulation results is analyzed, to find important parameters. The Simple Monte Carlo sampling of important parameters is conducted thousands times, from which the sampled values are used as the detector model's parameters. Then the detection efficiencies of the detector for multiple γ sources located at different spatial points are simulated via Monte Carlo N-Particle Transport Code, Version 5(MCNP5). The best parameters of detector can be determined by the minimum deviation between true efficiencies and simulation efficiencies. Take these best parameters as the detector model’s parameters, the results show that the relative errors between the simulation efficiencies and the true efficiencies for the sources 60Co, 137Cs, 241Am at the calibration points are all less than 0.5%, the relative errors between the simulation efficiencies and the true efficiencies at 3 verification points are all less than 0.5%.