用蒙特卡罗方法和MATLAB计算冷屏内壁表面辐射光线在探测器芯片上的分布状态

Computation of distribution of radiant rays from inner wall surface of cold shield on the detector chip with Monte Carlo method and MATLAB

以圆形冷屏中的640×512面阵器件为例,基于几何光学的基本原理,将冷屏内壁表面辐射抽象为一定数量、可用MATLAB随机产生的几何光线.追踪这些光线的去向,统计出其中直接投射、或者经过一次反射后落入探测器各光敏元的光线数量,通过直方图、散落点图等途径分析冷屏内壁表面辐射光线在探测器芯片上的分布状态.

Taking the 640×512 array device in a circular cold shield for example,the radiation from inner wall surface of the cold shield can be abstracted into a certain amount of geometric rays which could be generated randomly with MATLB. Through tracing their directions,the numbers of rays that projected directly or fallen after a reflection into the pixels of detector can be obtained.The distribution of radiant rays from inner wall surfaces of cold shield can be analyzed with histogram and spot diagram.