Electron Optics Simulator: A Three-Dimensional Finite-Element Electron Gun and Collector Design Tool

This paper reports the development of a fully 3-D finite-element (FE) design tool for the design of electron guns and collectors called the electron optics simulator (EOS). It is a module of the microwave tube simulator suite (MTSS) developed by the University of Electronic Science and Technology of China. EOS specifically targets problem classes including axisymmetric gun, gridded gun, multibeam gun, and multistage depressed collector. EOS is a steady-state trajectory code, which is a solver of electrostatic field and trajectory that takes into account secondary electrons, space-charge effects, and the external magnetic field. The simulator is dependent on the following two front-end features in MTSS: preprocessing that includes a solid modeling tool and a fully 3-D tetrahedral FE mesh automatic generator, and post processing for analysis and display of the results. A friendly interface is provided to design, test, optimize, and validate the electron optics systems. The aforementioned theoretical models are discussed in detail in this paper. In the end, some comparisons between simulation and experiment are presented.