提出了一种基于CsI(Tl)闪烁晶体和面阵CCD器件、采用光纤和光纤面板进行光耦合及传输、以扇形束线阵扫描方式实现对X光高分辨探测的方案。CsI(Tl)晶体的尺寸大小将直接影响到晶体的发光效率及X光的高分辨探测,据此开展了蒙特卡罗模拟研究。模拟研究了X射线能量、X射线源到探测晶体的距离(源距)、CsI(Tl)晶体的厚度与X射线能量分布、全能峰效率与CsI(Tl)闪烁晶体转换效率之间的关系。结果表明,当X射线能量为120～450 keV, CsI(Tl)晶体尺寸厚度为0～1.5 cm变化时,全能峰效率的变化范围为31.34～96.74％,CsI(Tl)闪烁晶体的转换效率的变化范围为12.8～97.43％。可见,X射线的能量及CsI(Tl)闪烁晶体尺寸的厚度,是决定X光高分辨探测的重要参量,这对优化X光高分辨探测用CsI(Tl)晶体的尺寸设计具有一定的参考价值。

A Xray detector, based on the CsI(Tl) scintillating crystal and areaarray CCD, using fiber and fiber optic plate to couple and transmit light with fanbeam linear array scanning, has been put forth. The luminescent efficiency and Xray high-resolution detection are directly influenced by the dimension of CsI(Tl) scintillating crystal, and Monte Carlo method is adopted to simulate the influences, including the relations between the energy of Xray, the distance between Xray source and the scintillating crystal, and the thickness of CsI(Tl) crystal and the Xray energy distribution, and then the whole energy peak efficiency and the transition efficiency. The results show that while the Xray energy is of 120～450 keV, and the thickness of CsI(Tl) crystal is 0.3～1.5 cm, the whole energy peak is within the range of 31.34%～96.74%, and the transition efficiency is within the range of 12.8%～97.43%. So, the Xray energy and the dimension of CsI(Tl) scintillating crystal are the most important parameters determining the Xray high resolution detection. It has certain referenced values to optimize the dimension design of CsI(Tl) scintillating crystal for Xray high resolution detection.