深圳大学光电子学研究所,广东深圳 518060

光电子学与激光技术; 条纹管; 球面荧光屏; 空间分辨率; 电子轨迹; 数值模拟; 有限差分法

Improvement of imaging performance for X-ray image tube
Zhang Jingjin, Lei Baoguo, and Yang Qinlao

Zhang Jingjin, Lei Baoguo, and Yang QinlaoInstitute of Optoelectronics, Shenzhen University, Shenzhen 518060, Guangdong Province, P.R.China

optoelectronics and laser technology; streak tube; spherical phosphor screen; spatial resolution; electron trajectory; numerical simulation; finite difference method

DOI: 10.3724/SP.J.1249.2017.01014


由于受到场曲的影响,条纹管的空间分辨能力随离轴高度增加而变弱.为了提高条纹管的整体分辨能力,利用有限差分法求解模拟X射线条纹管的电子光学结构,采用Monte Carol 方法和龙格库塔法追踪电子轨迹,得到电子轨迹最佳像面的形状,计算出具有实用性的球面荧光屏的曲率半径为83 mm,并制作出相应曲率的球面荧光屏用于测试. 通过实验观测以及理论分析证明,此球面荧光屏可使条纹管图像分辨能力提高1.2~1.3倍,有效提高条纹管单次测量所获取信息量.

Due to the field curvature, the spatial resolution of streak tube is deteriorated with the increment of the height of off-axis of electron beam. In order to improve the overall performance of streak tube, through simulation of the electro-optical of X-ray image tube by using finite difference method(FDM)and the trajectories tracing by Monte Carol sampling and Runge-Kutta method, we can obtain the geometric shape of optimized image plane. Thus, we design a spherical phosphor screen with the radius of curvature 83 mm, and fabricate the phosphor screen for experimental measurement. The result shows that the spherical phosphor screen can improve the spatial resolution of the existing X-ray image tube over 1.2 to 1.3 times and obtain more information in one shot effectively.