多参数耦合下电子枪静电聚焦特性分析

Electrostatic Focusing Characteristic of Electron Gun with Multi-Parameter Coupling

电子枪静电聚焦特性影响电子束焊接质量,目前没有系统的理论方法计算不同型号电子枪内反映静电聚焦特性的束腰参数。通过理论分析电子枪内轴上电位分布与电子束束腰半径和位置间的映射关系,阐释电子枪静电聚焦特性;采用CST仿真平台,以某电子枪为例,设置激励源参数和边界条件,构建某电子枪静电透镜分析模型,仿真不同结构参数下电子束束腰位置和束腰截面积,结合数值分析结果,探明不同结构参数对轴上电位的影响,验证电子枪静电透镜分析模型。仿真结果为电子枪关键参数的设计和优化提供理论支撑。

The electrostatic focusing characteristics of electron guns affect the quality of electron beam welding.At present, there is no systematic theoretical method to calculate the beam waist parameters that reflect the electrostatic focusing characteristics of different types of electron guns. The mapping relationships between the potential distribution on the axis of the electron gun and the beam waist radius and position of the electron gun are both theoretically analyzed. The electrostatic focusing characteristics of the electron gun are explored. Based on the CST simulation platform,one electron gun is taken as an example. The excitation source parameters and boundary conditions are numerically set.And the electrostatic lens analysis model of an electron gun is constructed. Moreover, the beam waist positions and cross-sectional areas of the electron beam under different structural parameters are acquired. Combined with the numerical analysis results, the effects of different structural parameters on the on-axis potential are discussed. And the electrostatic lens analysis model of the electron gun is verified according to the numerical analysis results. The simulation results provide theoretical support for the design and optimization of the key parameters aiming at the electron gun.