基于CdZnTe(CZT)大面积探测器的辐射探测技术研究

The study of radiation detection technology based on Cadmium Zinc Telluride (CdZnTe, CZT) compound semiconductor detector is one of the most popular research forefronts on radiation detection in the world. Earlier studies have focused on advanced radiation detection technology utilizing large-size CZT detectors in a current mode and investigation on the mechanism for the interaction of concerned material and the complex radiation field involving γ-ray, neutron, electron and so on, under extreme conditions with instantaneous activity and high-energy radiation source. It's very valuable to reveal the effects of microscopic properties inside material on the macroscopic radiation detector performances. Recently, the appearance of CZT detector is attracting a lot of attention from researchers and engineers all over the world, because this material has a large number of excellent radiation detection capabilities, such as high resistivity, large bandgap, high density, good energy resolution, great photoelectric conversion efficiency, strong radiation hardness, and being able to work at room temperature. Thus, CZT crystal is becoming the most promising material for a large scale of research areas. It can be widely used in aerospace, nuclear medicine, industrial non-destructive testing, nuclear safety and good-sized nuclear devices. In this project, we plan to emphasis several key science topics as follows: (1) scientific and technologic problems within the manufacturing of large-size CZT detectors, (2) experiments on radiation detection properties utilizing large-size CZT detectors, (3) newly found effects and disciplines on the interaction of radiation sensitive material with complex radiation field with instantaneous activity and high-energy radiation source. We hope that this project will make an important contribution to the extension and developing of advanced radiation detection technology.

基于碲锌镉(CZT)的新型化合物半导体探测器的辐射探测技术研究是国际上辐射探测的重要前沿及热点研究领域。开展基于大面积、电流型CZT探测器的先进辐射探测技术研究，探索瞬时、高能量、极端条件下的复杂辐射场(伽马、中子、电子等)与物质相互作用机理，对于揭示材料内部的微观特性与探测器宏观辐射探测性能之间的关系，具有重要价值。近年来，这种具有高电阻率、宽禁带、高密度、高光电探测效率、强抗辐照能力并可室温操作等优良辐射探测性能的探测材料的出现，引起人们极大的关注，在航空航天、核医学、工业无损检测、核安全及大型核科学装置的研究等领域应用广阔。本项目拟重点研究如下关键科学问题：(1)大面积CZT探测器研制中的科学技术问题研究(2)大面积CZT探测器辐射探测性能的实验研究(3)瞬时、高能量、复杂辐射场与探测灵敏物质相互作用的新效应、新规律研究。希望本项目为先进辐射探测技术前沿的开拓作出重要贡献。

基于碲锌镉(CZT)的新型化合物半导体探测器的辐射探测技术研究是国际上辐射探测的重要前沿及热点研究领域，开展基于大面积CZT探测器的先进辐射探测技术研究，探索瞬时、高能量极端条件下的复杂辐射场（伽马，中子，电子等）与物质相互作用机理，对于揭示材料内部的微观特性与探测器宏观辐射探测性能之间的关系，具有重要价值。本项目提出了基于大面积CZT探测器的辐射探测技术研究，采用理论分析、数值模拟和实验研究相结合的方法，从电流型CZT探测器的探测原理和信号构成出发，构建半导体物理性质与探测器性能之间的关系，分析研究探测器的探测灵敏度、能量响应、时间响应等关键特性，提出和验证大面积高灵敏探测器构建技术。研究结果表明：1) CZT探测器对1.25 MeV伽马射线的灵敏度可达1E-15 C•cm2/MeV；2) 上升时间为4 ns，脉冲半宽为30 ns；3) 最大线性电流高于1 A；4) 当14 MeV中子辐照总剂量为1E10 neutrons•cm-2时，探测器脉冲辐射探测性能基本不变。本项目成果可为脉冲伽马探测提供关键科学仪器的研制方法和技术途径，具有重要的研究和应用价值。