Qin Feng, Zhao Rui, Zhu Wei Feng, Deng Ning Qin, Jiao Zhi Wei, Tang Xian Qiang, Wu Jin Jie
China Jiliang University, Hangzhou, 310018, China.
National Institute of Metrology, Beijing, 100029, China.
Heliyon. 2023 Aug 1;9(8):e18875. doi: 10.1016/j.heliyon.2023.e18875. eCollection 2023 Aug.
In recent years, higher requirements have been placed on the response characteristics of X-ray detectors in the field of medical diagnostic imaging. Due to this, high sensitivity, high attenuation coefficient and low cost detection materials need to be developed. In this paper, the geometric model of a detector was established by Geant4 code. The absorption efficiency and mass attenuation coefficient of MAPbBr crystals were calculated in the energy range of 30 keV to 100 keV. Compared with the mass attenuation coefficient of the NIST database, the deviation was within 1.39%. The signal charge number and detection sensitivity of the X-ray interaction with the MAPbBr crystal ware calculated. Compared with the CdTe crystal and α-Se, the MAPbBr crystal still had a larger detection sensitivity under a smaller applied electric field, which was approximately 9 times higher than that of α-Se. This result indicated that the detection sensitivity could be greatly improved by using a high atomic number and high charge mobility-lifetime product. Based on the simulation results, the 2 mm thick MAPbBr crystal exhibited the highest detection sensitivity at 60 keV X-rays, which was in agreement with the experimental results.
近年来，医学诊断成像领域对X射线探测器的响应特性提出了更高的要求。因此，需要开发高灵敏度、高衰减系数和低成本的探测材料。本文利用Geant4代码建立了探测器的几何模型。计算了MAPbBr晶体在30keV至100keV能量范围内的吸收效率和质量衰减系数。与NIST数据库的质量衰减系数相比，偏差在1.39%以内。计算了X射线与MAPbBr晶体相互作用的信号电荷量和探测灵敏度。与CdTe晶体和α-Se相比，MAPbBr晶体在较小的外加电场下仍具有较大的探测灵敏度，约为α-Se的9倍。该结果表明，使用高原子序数和高电荷迁移率-寿命乘积可以大大提高探测灵敏度。基于模拟结果，2mm厚的MAPbBr晶体在60keV X射线下表现出最高的探测灵敏度，这与实验结果一致。
