闪光照相中转换屏的特性研究

Character Study of Scintillator in Radiography System

在高能 X光辐射照相系统中 ,通常将 X光转换为可见光进行探测 ,在闪光机参数确定的情况下 ,转换屏的性能对照相系统灵敏度、空间分辨率起决定性作用。本文首先推导出了转换屏的量子效率公式 ;其次在考虑散射的情况下 ,建立了光子在转换屏中迁移时满足的扩散方程 ,推导出转换屏的调制传递函数 ( MTF)公式。

X ray is always transformed to visible light for detection by scintillator in high energy radiography systems. When the parameter of X-ray is defined, the scintillator's character plays an important role in the sensitivity and spatial resolution of radiography systems. At first, the quantum efficiency is analysed. Then the diffuse equation is set up to describe the movement of the photons in the scintillator while the dispersion is taken into account. As a result,scintillator's MTF is given.