基于电子追迹算法的微光像增强器分辨力研究  

Resolution Research of Low-light-level Image Intensifier Based on Electronic Trajectory Tracking

作　　者：邱亚峰[1] 严武凌 华桑暾 QIU Ya-feng;YAN Wu-ling;HUA Sang-tun(School of Mechanical Engineering,Nanjing University of Science and Technology,Nanjing 210094,China)

机构地区：[1]南京理工大学机械工程学院,南京210094

出　　处：《光子学报》2020年第12期19-26,共8页Acta Photonica Sinica

基　　金：国防预研基金(No.1171011485)。

摘　　要：针对目前的微光像增强器分辨力计算理论模型存在着不够精确,不能直观给出优化条件等问题,提出了一种基于电子追迹算法的理论模型.通过均匀掺杂GaAs电子散射公式对阴极内光电子运输建模得到不同于朗伯体分布的出射电子分布,将近贴系统近似为纵向均匀电场并建立前、后近贴电子输运模型,在非异常工作情况下以次级电子出射分布为基础建立微通道板内电子输运模型,最后得到荧光屏电子圆斑,并用蒙特卡洛法计算调制传递函数,以0.3为标准得到极限分辨力.对四种不同型号像管的分辨力进行计算,计算结果与实验结果最大误差仅为5.0%,低于已有模型误差(超过10%),证明了该模型具有较好的实用价值和应用前景.Aiming at the problem that the current theoretical models for calculating the resolutions of low-light-level image intensifiers are not accurate enough and can’t provide the optimization conditions intuitively,a theoretical model based on electron tracking is proposed.Electron scattering formula of uniform-doping GaAs photocathodes is used for obtainig the distribution of emitted electrons,which is different from the Lambertian distribution.The proximity system is approximated to a longitudinal uniform electric field to establish the electron transport model.Based on the secondary electron emission distribution,the electron transport model in the microchannel plate is established under non-abnormal working conditions.With the distribution of the electron beams on the phosphor screen,the modulation transfer function is calculated by Monte Carlo method,and the limiting resolution is obtained by taking the standard value as 0.3.The resolutions of four different types of image intensifiers are calculated,and the results show that the largest error between the model simulation results and the experimental results is only 5.0%,less than the errors from the existing models(more than 10%),which proves the practical value and good application prospect of the model.

关 键 词：像增强器 光电阴极 电子轨迹 分辨力 调制传递函数 

分 类 号：TN223[电子电信—物理电子学]