中国激光, 2017, 44 (12): 1204004, 网络出版: 2017-12-11
条纹相机中栅网的特性研究
Characteristics of Mesh in Streak Camera
成像系统 X射线探测器 条纹相机 栅网 二次电子 电场扰动 子透镜效应 imaging system X-ray detector streak camera mesh secondary electron electric field disturbance sub-lens effect
摘要
栅网是条纹相机等电子光学仪器的重要组成部件。通过使用有限差分法对栅网的丝径、网孔进行精细建模, 分析了栅网对均匀电场的扰动以及对电子运动的子透镜效应; 使用电子碰撞自由程Gryzinski理论研究了电子和栅网碰撞的二次电子发射问题。结果发现, 对于条纹相机中常用的10, 33, 50 line/mm栅网, 其结构参数的不连续性对均匀电场的扰动分别为0.31%、0.07%、0.04%; 对于入射能量为15 keV的电子, 栅网金属原子Ni、Cr和Cu的非弹性散射碰撞自由程分别为6.85, 10.34, 7.25 nm, 碰撞很难产生二次电子发射。研究结果对电子光学仪器的设计和栅网参数的优化具有参考意义。
Abstract
Mesh is an important component of electronic optical instruments such as streak cameras. In this paper, the finite difference method is used to model the wire diameter and wire hole of the mesh. The effects of the mesh on the disturbance of uniform electric field and the sub-lens effect of electron motion are analyzed. The secondary electron emission problem of collisions of electrons and mesh is studied by Gryzinski theory. The results show that the disturbances of the structural parameters are 0.31%, 0.07% and 0.04%, respectively, for the 10 line/mm, 33 line/mm and 50 line/mm mesh in the streak camera. For the electrons with energy of 15 keV, the non-elastic scattering collision free paths of Ni, Cr and Cu atoms are 6.85 nm, 10.34 nm and 7.25 nm, respectively, and it is difficult to produce secondary electron emission. The results have reference significance for the optimization of electronic optical instrument design and mesh parameters.
顾礼, 李翔, 周军兰, 杨勤劳, 郭宝平. 条纹相机中栅网的特性研究[J]. 中国激光, 2017, 44(12): 1204004. Gu Li, Li Xiang, Zhou Junlan, Yang Qinlao, Guo Baoping. Characteristics of Mesh in Streak Camera[J]. Chinese Journal of Lasers, 2017, 44(12): 1204004.