A Novel Technique for Optimizing 270°-Bent Electron Gun for Evaporation Applications

Abstract

In this article, a novel approach for optimizing a practical 270° bent electron gun has been proposed by using JUPYTER NOTEBOOK, an open-source web application utilizing PYTHON script, aiding faster data processing and mathematical computations. For this purpose, a 3-D cost function has been formulated to optimize the position of the anode with respect to the filament which aims at maximizing the beam power density, maximizing beam parallelism or laminar flow and optimizing beam shape. CST Studio-Particle Tracking Module is used for gun design, magnetic field design, and for the study and analysis of generated electron beam trajectories by performing both electrostatic and electromagnetic 3-D gun simulations. Unlike the conventional 270° bent transverse electron guns using Helmholtz coils for generating uniform magnetic fields, here permanent magnets have been used for generating nonuniform magnetic fields making the overall system compact along with electromagnets and magnetic shunts for precise beam maneuvering. Magnetic fields are experimentally measured by using Gauss meter which match well with that of the simulated values. The electron gun was fabricated and trial experiments were conducted under high vacuum environment. Experimental validation was done by puncturing a stainless steel plate kept at 90° and 270° positions above the crucible and the results match well with the simulated results.