X射线/γ射线直接转换探测器的设计  

Design of The Direct X-Ray/γ-Ray Detector

作　　者：吴忠[1] 丁奕婧 PREMKUMAR Sellan 周建明 雷威[1] WU Zhong;DING Yijing;PREMKUMAR Sellan;ZHOU Jianming;LEI Wei(Joint International Research Laboratory of Information Display and Visualization,Southeast University,Nanjing Jiangsu 210096,China;SuZhou YiXian Optoelectronic Technology Co.,Ltd.,Suzhou Jiangsu 215000,China)

机构地区：[1]东南大学信息显示与可视化国际联合实验室,江苏南京210096 [2]苏州亿现光电子科技有限公司,江苏苏州215000

出　　处：《传感技术学报》2022年第12期1598-1602,共5页Chinese Journal of Sensors and Actuators

基　　金：国家重点研发计划项目(2018YFE0125500,2021YFE0105900);国家自然科学基金项目(62175028,51879042,61674029);江苏省国际合作项目(BZ2022008)。

摘　　要：X射线/γ射线的探测和成像在医学影像、安全检查以及工业无损探伤等方面有重要的应用。与通过闪烁体的间接转换探测模式相比,直接将X射线/γ射线光子转换为电子/空穴对的探测模式可以具有更高的量子效率。但是高能X射线/γ射线与固态半导体材料的互作用物理过程比较复杂,它不仅包含光电效应,可能还有散射效应、康普顿效应,以及电子对效应等。另外,光生载流子在半导体探测器中通过漂移、扩散和复合等复杂的输运过程形成光电流。由于对高能X射线/γ射线光子探测物理过程比较复杂,缺乏有效的数值计算模型和方法对X射线/γ射线直接转换探测器进行理论设计。本文根据X射线/γ射线与半导体互作用过程,以及光生载流子的输运过程,提出了一套X射线/γ射线直接转换探测器的数值计算模型。经过与实验结果的对比验证,该计算模型可以较准确地模拟高能光子吸收以及光生载流子的收集过程,它为研制性能优秀的X射线/γ射线探测成像器件提供了设计工具。X-ray/γ-ray detection and imaging have important applications in medical inspections,security monitoring,and noninvasive industrial detections.Comparison with the indirect conversion detection with scintillators,the direct conversion detection converting the X-ray/γ-ray photons into electron/hole pairs has higher quantum efficiency.However,the interaction of X-ray/γ-ray photons with solid target is quite complicated.It includes scattering,photoelectrical effect,Compton effect,pair productions,and etc..Apart from this,the transportation of photon induced carriers is also complicated,including diffusion,drift,and recombination.Due to those complicated physical process,the simulation tool for the direct X-ray/γ-ray detector is seldom reported.In this article,a few simulation models are proposed to analyse the physical process of absorption of X-ray/γ-ray photons,and the transportation of carriers.As the comparison between the simulation results and experimental results shown,these simulation models can be used to simulate and design the X-ray/γ-ray detector accurately.

关 键 词：X射线/γ射线直接探测 光电效应 散射效应 康普顿效应 电子对效应 

分 类 号：TL816.1[核科学技术—核技术及应用]