狭长CsI(Tl)闪烁体发光效率的研究

提出了基于狭长CsI（Tl）闪烁体和面阵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射线探测与成像的工业X-CT系统探测器方案.基此，通过物理分析及数学建模，利用Matlab模拟研究了X光能量小于450 keV时狭长CsI（Tl）闪烁体的发光效率等性能指标.研究结果表明：当光电吸收截面μph和康普顿吸收截面μc分别为0.000313和0.0000295、反射层反射系数R和衬底反射系数Rs分别取0.95和0.8、荧光线性吸收系数σ取0.000222 μm－1时，得到狭长CsI(Tl)闪烁晶体的长度l、高度h和宽度w取值范围分别是926～4512 μm、242～5000 μm和242～5000 μm的结论.在此范围内，既可使闪烁晶体有较好的空间分辨率又可获得最高的发光效率.

Study of the Luminescent Efficiency for Narrow CsI (Tl) Scintillator

An X-ray detector project,based on the narrow CsI(Tl) scintillating crystal and area-array CCD,using fiber optic and fiber optic plate as light coupled and transmission with fan-beam linear array scanning,has been put forth in this paper. Below 450 keV for x-ray energy,on the base of the physical analyzing and mathematical modeling,the luminescent efficiency property of narrow CsI(Tl)scintillation crystal has been studied by using Matlab. While the parameters of μph、μc、R、Rs、and σ equal to 0.00313,0.0000295,0.95,0.8,and 0.000222 μm－1respectively,it is concluded that the length range of the narrow CsI(Tl) scintillation crystal is 926～4512 μm,the height range is 242～5000 μm,and the width is 242～5000 μm. In the range of the above size,it can be obtained that space(or geometry) resolution of the narrow CsI(Tl) scintillation crystal is better and luminescent efficiency is also the highest.