高輝度電子銃の特性解析のための陰極形状モデリング法

Abstract

To study the operating characteristics of a high brightness electron gun, the modeling of the tip evolution of a point cathode was combined with the electric field solver using the surface charge method. The modeling is based on a numerical integration of differential equation describing matter transport phenomena caused by surface diffusion of atoms. The combined program makes it possible to model the tip evolution including the effect of field force acting in opposite directions to surface tension force. The tip evolution under high electric field was examined for different initial tip radii. The cathode maintains a small tip radius for a long period of time, which is caused by the field force. The modeling provides the time variations of the tip shape and the field distribution along the tip surface.