CdZnTe伽马射线探测器的能谱特性分析

人工晶体学报 ›› 2021, Vol. 50 ›› Issue (10): 1883-1891.

CdZnTe伽马射线探测器的能谱特性分析

于晖^1,2, 张蒙蒙², 杜园园³, 席守智^1,2, 查钢强², 介万奇²

1.陕西迪泰克新材料有限公司,西安 712034;
2.西北工业大学材料学院,凝固技术国家重点实验室,辐射探测材料与器件工信部重点实验室,西安 710072;
3.中国科学院高能物理研究所,粒子天体物理重点实验室,北京 100049

收稿日期:2021-06-21 出版日期:2021-10-15 发布日期:2021-11-24
通讯作者: 介万奇,博士,教授。E-mail:jwq@nwpu.edu.cn
作者简介:于晖(1983—),女,陕西省人,工程师。E-mail:yuhuinwpu@nwpu.edu.cn。介万奇(1959—),教授,博士生导师。国家杰出青年基金获得者,教育部“长江学者”特聘教授,现为中国材料学会常务理事,《人工晶体学报》副主编。主要从事金属凝固和化合物半导体晶体生长原理与技术研究。曾先后主持国家重点研发计划项目、国家重点基础研究项目(973)、国防基础研究项目、国家自然科学基金重点项目等30余项。获国家技术发明二等奖2项,国家科技进步二等奖1项,省部级科技成果奖8项,发表论文500余篇,获授权发明专利26项,独著专著1部,合作专著2部。技术成果达到国际先进水平,并在多个领域实现应用。
基金资助:
国家自然科学基金(61874089);西安市科技计划(2020KJRC0121)

Analysis on Energy Spectra for CdZnTe Gamma Ray Detector

YU Hui^1,2, ZHANG Mengmeng², DU Yuanyuan³, XI Shouzhi^1,2, ZHA Gangqiang², JIE Wanqi²

1. Shaanxi Imdetek New Materials Co., Ltd., Xi'an 712034, China;
2. Key Laboratory of Radiation Detection Materials and Devices, Ministry of Industry and Information Technology, State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an 710072, China;
3. Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Science, Beijing 100049, China

Received:2021-06-21 Online:2021-10-15 Published:2021-11-24

摘要/Abstract

摘要： CdZnTe(CZT)探测器目前在国内外天体物理研究中占有重要的地位。本文采用蒙特卡洛软件GEANT4模拟了CZT伽马射线探测器对伽马射线的能谱响应,研究了电子和空穴的输运特性、外加偏压、探测器厚度等因素对平面型探测器的能谱特性的影响规律。结果表明,在电子收集效率较高时,能量分辨率明显受迁移率寿命积比值((μτ)_e/(μτ)_h)的影响,比值越小,能量分辨率越好。增加工作电压可以提高载流子的收集效率和探测器的能量分辨率。在电子收集效率较高时,增大厚度可以弱化空穴信号贡献,提高能量分辨率。漂移程与晶体厚度之比(μτ)_eE/d可以用来估算平面型CZT探测器对低能射线的收集效率,并计算出其对应关系。

关键词: 辐射探测晶体, 伽马射线探测器, CdZnTe探测器, GEANT4, CdZnTe晶体, 能量分辨率, 能谱

Abstract: CdZnTe detectors play an important role in international astronomy research. In this paper, the spectra response of CdZnTe planar detector for γ-ray was numerically simulated using GEANT4 Monte-Carlo simulation toolkit, and the influence of the factors, such as transport properties of electrons and holes, applied bias voltage, thickness of detector and other factors were studied. The calculated results show that when the charge collection efficiency (CCE) of electron is high, the dependence of energy resolution on the ratio of electron and hole mobility-lifetime product ((μτ)_e/(μτ)_h) is strong, and the resolution increases with the decrease of the ratio. The energy resolution and CCE of carrier can be improved by raising up the bias. When the CCE of electron is high, increasing thickness can weaken the hole signal contribution to the total induced charge, and improve the energy resolution. The value of (μτ)_eE/d can be used to evaluate CCE of planar CdZnTe detectors for rays of low energy, and the corresponding relationship was calculated.

Key words: radiation detection crystal, gamma ray detector, CdZnTe detector, GEANT4, CdZnTe crystal, energy resolution, energy spectrum

中图分类号:

P172.3
O734

于晖, 张蒙蒙, 杜园园, 席守智, 查钢强, 介万奇. CdZnTe伽马射线探测器的能谱特性分析[J]. 人工晶体学报, 2021, 50(10): 1883-1891.

YU Hui, ZHANG Mengmeng, DU Yuanyuan, XI Shouzhi, ZHA Gangqiang, JIE Wanqi. Analysis on Energy Spectra for CdZnTe Gamma Ray Detector[J]. JOURNAL OF SYNTHETIC CRYSTALS, 2021, 50(10): 1883-1891.

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