高纯锗探测器瞬态温度场特性的模拟研究  

Simulation study on transient temperature field characteristics of HPGe detectors simulated by the COMSOL method

作　　者：阙子昂 郝晓勇[1] 何高魁[1] 刘洋[1] 赵江滨[1] 田华阳[1] QUE Ziang;HAO Xiaoyong;HE Gaokui;LIU Yang;ZHAO Jiangbin;TIAN Huayang(China Institute of Atomic Energy,Beijing 102413,China)

机构地区：[1]中国原子能科学研究院,北京102413

出　　处：《核技术》2024年第9期69-76,共8页Nuclear Techniques

基　　金：国防科工局核能开发科研项目(No.HNKF202224(28))资助。

摘　　要：为确保探测器在低温环境下稳定运行,分析了高纯锗探测器的内部传热机理,基于COMSOL Multiphysics软件建立了探测器的三维计算模型,得到了制冷过程中三维瞬态温度分布规律以及不同探测器内部结构和材料选择对温度分布的影响,通过仿真数据与实验数据的一致性比较,验证了该模型及仿真方法的正确性。为进一步优化和改进液氮制冷和电制冷型高纯锗探测器的设计参数提供了理论支撑。[Background]High-purity Ge(HPGe)detectors are widely used in nuclear science,technology,and national defense because of their excellent energy resolution capability,which enables them to fingerprint gamma rays and accurately determine nuclide types and intensities.However,HPGe detectors typically need to be cooled to low temperatures for normal operation to prevent excessive thermal noise at room temperature.[Purpose]This study aims to investigate the heat transfer process and temperature distribution law inside a HPGe detector to ensure the stable operation of the detector in a low-temperature environment.[Methods]Through the analysis of the heat transfer mechanism of the high-purity germanium(HPGe)detector,the internal heat transfer structure and a threedimensional heat transfer model were constructed.COMSOL software was utilized to simulate the internal temperature distribution of the HPGe detector under liquid nitrogen refrigeration,as well as to investigate the effects of varying refrigeration times and packaging structures on this distribution.Based on these simulations,the packaging structure of the HPGe detector was optimized.Additionally,a temperature testing platform for the detector was constructed,and the simulation results were compared with experimental data to validate the model's accuracy.[Results]The simulation results demonstrate that the detector model achieves dynamic equilibrium after 6 h of cooling,with the minimum internal temperature at the tip of the cold finger approximately -175℃.The utilization of oxygen-free copper as the cold chain material,combined with a low heat leakage and high-strength support material for the cold finger,enhances refrigeration efficiency.Additionally,the Dewar is designed with a sidewall thickness of 1.5 mm,and the spacing between the sidewall and the crystal cylinder is set at 3 mm.These design features collectively facilitate the detector's attainment of a lower limiting refrigeration temperature.[Conclusions]The modeling and temperature field simulation me

关 键 词：高纯锗探测器 传热机理 温度分布 探测器结构 

分 类 号：TL818[核科学技术—核技术及应用]