强激光与粒子束, 2016, 28 (4): 045106, 网络出版: 2016-04-01
滚边法测量高能X射线源焦斑大小
High energy X-ray spot size measurement with rollbar
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。
Abstract
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-Ⅱ linear induction accelerator downstream and target, the X-ray spot size is measured and the results are analyzed.
李勤, 王毅, 李成刚, 李洪, 祁双喜, 刘云龙, 程晋明, 李天涛, 龙全红. 滚边法测量高能X射线源焦斑大小[J]. 强激光与粒子束, 2016, 28(4): 045106. Li Qin, Wang Yi, Li Chenggang, Li Hong, Qi Shuangxi, Liu Yunlong, Cheng Jinming, Li Tiantao, Long Quanhong. High energy X-ray spot size measurement with rollbar[J]. High Power Laser and Particle Beams, 2016, 28(4): 045106.
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