滚边法测量高能X射线源焦斑大小  

High energy X-ray spot size measurement with rollbar

作　　者：李勤[1] 王毅[1] 李成刚[1] 李洪[1] 祁双喜[1] 刘云龙[1] 程晋明[1] 李天涛[1] 龙全红[1] 

机构地区：[1]中国工程物理研究院流体物理研究所,四川绵阳621900

出　　处：《强激光与粒子束》2016年第4期184-189,共6页High Power Laser and Particle Beams

基　　金：国防科技专项研究基金项目

摘　　要：应用于高能闪光X光照相技术的X射线源焦斑大小是闪光照相装置的关键参数,直接影响成像的分辨能力。由于高能X射线的强穿透性和强辐射环境,给焦斑测量带来一定困难。介绍了一种间接测量方法,采用滚边装置(rollbar)成像得到X射线源的边扩展函数,微分后得到光源的线扩展函数并计算调制传递函数(MTF),而后从MTF为0.5所对应的空间频率之值确定出光源的光斑大小。给出了神龙二号加速器电子束聚焦调试实验中得到的X射线焦斑测量结果,分析影响测量结果的因素并提出了解决方法。The X-ray spot size is a critical parameter for flash radiography facility which degrades resolution in the flash radiography.It is difficult to measure the X-ray spot size in the condition of intense radiation and its penetrability.This paper describes a rollbar used to measure the X-ray focal spot size.The edge spread function(ESF),line spread function(LSF)and modulation transfer function(MTF)of the X-ray spot are obtained from the rollbar image data,and the X-ray spot size is determined by the MTF.In the experiment of Dragon-Ⅱlinear induction accelerator downstream and target,the X-ray spot size is measured and the results are analyzed.

关 键 词：高能X射线 焦斑大小 调制传递函数 滚边装置 

分 类 号：TN249[电子电信—物理电子学]