X射线管强制冷却对焦点位移的影响  

The Effect of Forced Cooling of X-Ray Tube on Focalspot Displacement

作　　者：任翔[1] REN Xiang(First Research Institute of The Ministry of Public Security of People's Republic of China,Beijing 100048,China)

机构地区：[1]公安部第一研究所,北京100048

出　　处：《真空电子技术》2021年第5期68-72,共5页Vacuum Electronics

基　　金：国家重点研发计划资助项目(2018YFF0109903)。

摘　　要：X射线安全检查设备是目前普遍采用的一种必备的安全措施。随着技术指标逐渐向着大功率方向发展,图像背景不均问题越来越明显,其中一个原因是X射线管的焦点在工作时产生了位移,使得接收端的X射线强度发生了变化。本文从X射线管的工作原理出发,根据热力学第一定律和传热学原理,理论上论证了焦点位移是由阳极的热膨胀引起,位移量的大小由达到热稳态时阳极的平均温升决定。为了验证以上理论,采用了一种强制冷却方式的X射线管作为研究对象。首先介绍了其结构特点和强制冷却的工作方式,以及测量焦点位移的测试平台和测试方法,然后分别测量了使用和不使用强制冷却工作方式时的焦点位移量,通过对比得出使用强制冷却工作方式时的焦点位移量更小的结论。The X-ray security inspection equipment is a necessary security measure which is widely adopted at present.With the gradual development of technical indicators in the direction of high power,the problem of uneven image background becomes more and more obvious.One of the reasons is that the focal spot of the X-ray tube is displaced when it is working,which changes the X-ray intensity at the receiving end.Based on the working principle of the X-ray tube,according to the first law of thermodynamics and the principle of heat transfer,this paper theoretically demonstrates that the focal spot displacement is caused by the thermal expansion of the anode,and the magnitude of the displacement is determined by the average temperature rise of the anode when the steady-state conduction is reached.In order to verify the above inference,a forced cooling X-ray tube was used as the research object.This paper introduces the structural characteristics and forced cooling working methods,as well as the test platform and test methods for measuring focal spot displacement.The focal spot displacements are measured respectively with and without forced cooling.The comparative results indicate that the focus displacement with forced cooling is smaller.

关 键 词：X射线管 焦点位移 热膨胀 强制冷却 

分 类 号：TN14[电子电信—物理电子学]