基于Matlab的磁透镜场分布计算与优化分析

Calculation and optimization analysis of magnetic lens field distribution based on Matlab

磁透镜聚焦是获得微束斑电子束的一种主要方法,磁透镜的场分布直接影响着电子束的品质。为了解决商业软件难以实现的磁透镜参数化设计,本文基于Matlab编制了计算磁透镜场分布的有限元法程序,实现了磁透镜参量的系列化设计,并搭建了磁场测量平台进行实验验证,仿真值与实验值的相对误差<5%。在此基础上,编制的程序能够对磁场值是否饱和进行实时判断,进而微调控饱和区域优化透镜结构消除磁饱和点。

Focusing of magnetic lens is one of the main methods to obtain microbeam spot electron beam.The field distribution of magnetic lens directly affects the quality of electron beam.In order to solve the difficulty of parametric design of magnetic lens in commercial software,a finite element program based on Matlab is developed to calculate the magnetic field distribution of magnetic lens.At the same time,a magnetic field measurement platform is built for experimental verification.The relative error between the simulation value and the experimental value is less than 5%.On this basis,the program can judge whether the magnetic field at each point is saturated in real time and then adjust the saturated region to optimize the lens structure and to eliminate the magnetic saturation point.