中子对碲锌镉辐照损伤模拟研究  

Simulation study of neutron radiation damage to cadmium zinc telluride

作　　者：魏雯静 高旭东 吕亮亮 许楠楠[1] 李公平[1] Wei Wen-Jing;Gao Xu-Dong;LüLiang-Liang;Xu Nan-Nan;Li Gong-Ping(School of Nuclear Science and Techology,Lanzhou University,Lanzhou 730000,China)

机构地区：[1]兰州大学核科学与技术学院,兰州730000

出　　处：《物理学报》2022年第22期220-229,共10页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11975006,11575074);兰州大学特殊功能材料与结构设计教育部重点实验室(B类)2021年开放课题(批准号:lzujbky-2021-kb06)资助的课题。

摘　　要：碲锌镉探测器长期暴露于辐射环境下时,会形成不同程度的辐照损伤,影响器件性能甚至失效,极大缩短探测器在辐射场中的服役时限.本文首先利用Geant4程序包对能量为1.00—14.00 MeV的中子在碲锌镉中的输运过程进行模拟,获取初级离位原子的信息,进而结合级联碰撞模型,对不同能量的中子在碲锌镉材料中造成的辐照损伤进行模拟计算.计算结果表明初级离位原子能量大部分位于低能端,并随着入射中子能量升高,初级离位原子的种类更加丰富,能量也逐渐增大;中子辐照碲锌镉材料时非电离能损沿着深度方向均匀分布,且非电离能损随着入射中子能量的增加呈现先增大后减小的趋势;辐照损伤量—原子离位次数(dpa)的计算结果表明, dpa也随入射中子能量升高呈先增大后减小的趋势,进一步分析可知随着入射中子能量增大,非弹性散射成为造成材料内部离位损伤的主要因素.In recent years, the development of new semiconductor materials has made an opportunity and challenge for technological innovation and the development of emerging industries. Among them, cadmium zinc telluride materials have highlighted important application prospects due to their excellent properties. The CdZnTe, as the third-generation cutting-edge strategic semiconductor material, has the advantages of high detection efficiency, low dark current, strong portability, and applicability at room temperature without additional cooling system. However, when the cadmium zinc telluride detector is exposed to radiation environment for a long time, it will cause different degrees of radiation damage, which will affect the performance of the device or even fail to work, and greatly shorten the service time of the detector in the radiation field. The transport process of 1.00 –14.00 MeV neutrons in CdZnTe material is simulated to obtain the information about the primary knock-on atoms, and then by combining with the cascade collision model, the irradiation of neutrons with different energy in CdZnTe material is analyzed. The damage is simulated and calculated. The calculation results are shown below. The energy of most of the primary knock-on atoms is located at the low-energy end,and with the increase of the incident neutron energy, the types of primary knock-on atoms are more abundant,and the energy also increases gradually. With neutron irradiation of CdZnTe, the non-ionizing energy loss is uniformly distributed along the depth direction in the material, and the non-ionizing energy loss first increases and then decreases with the increase of the incident neutron energy. The calculation results of displacements per atom(dpa) show that the dpa also increases first with the increase of the incident neutron energy. And further analysis shows that the number of Te displacement atom atoms and the number of the Zn displacement atoms both increase first and decrease then with the increase of incident neutron energy, while th

关 键 词：中子辐照 碲锌镉 辐照损伤 Geant4模拟 

分 类 号：TL816.3[核科学技术—核技术及应用]