X射线增感屏点扩散函数的Monte Carlo模拟

研制了一通用的Monte Carlo程序来研究X射线增感屏以及成象系统的性能，该程序主要包括三部分，分别描述了所发生的相应的物理过程：X射线的散射和吸收，次级电子的作用及可见光子的扩散，对程序进行了验证，对于一种Gd2O2S:Tb增感屏，计算了其在不同入射X射线能量下的点扩散函数。

MONTE CARLO SIMULATION OFPOINT SPREAD FUNCTION OF INTENSIFYING SCREENS

A general Monte Carlo program has been developed to study theperformance of the X-ray intensifying screens and imaging systems. The program contains three major parts, each of which describes one of the interaction steps occuring in the system:the absorption and scattering of X-rays, the diffusion of generated electrons, and the diffusion of light photons. Through comprehensive verification, it shows that the simulation methods for all physical processes are correct and the results obtained are credible. For a kind of Gd2O2S:Tb intensifying screen, several characteristic parameters such as the number of collected light photons, light collection efficiency and PSF depending on the incident X-ray energy are calculated. These basic physical quantities are useful for the prediction of the information transfer properties of a phosphor layer.