HPGe 探测器晶体尺寸及效率的研究

采用蒙特卡罗方法模拟计算光子的探测效率需对高纯锗( HPGe ) 探测器进行准确的建模。模拟计算研究了HPGe 晶体长度对探测效率的影响，并在空间不同的测量位置对放射源进行测量，将模拟计算与实验测量相结合，对探测器晶体的尺寸进行调整，获得了HPGe 探测器晶体的模拟计算的准确尺寸，并在122s1 332 keV 能量范围内对模拟结果进行了验证。结果表明，在此能量范围内HPGe 探测器的探测效率的模拟计算值与实验测量值的相对偏差大多数在5% 内，并建立点源探测效率与探测器轴向距离的关系。The accurate shape of HPGe detector is needed in order to calculate its detection efficiency with Monte Carlo methods. In our calculation, the influence of the HPGe crystal size on efficiency has been investigated; the final crystal sizes were determined by comparison with experiments and were validated by the experimental efficiency obtained at several source-to-detector positions. The results show that when the crystal dimensions determined are used to calculate the detection efficiency in the energy range 122s1 332 keV, the relative deviations between simulated and most experimental results were within 5%. In addition, the relationship between detection efficiency and axial distance to detector was established.

Study on Crystal Size and Detection Efficiency of HPGe Detector

The accurate shape of HPGe detector is needed in order to calculate its detection efficiency with Monte Carlo methods. In our calculation, the influence of the HPGe crystal size on efficiency has been investigated; the final crystal sizes were determined by comparison with experiments and were validated by the experimental efficiency obtained at several source-to-detector positions. The results show that when the crystal dimensions determined are used to calculate the detection efficiency in the energy range 122s1 332 keV, the relative deviations between simulated and most experimental results were within 5%. In addition, the relationship between detection efficiency and axial distance to detector was established.