Optimal Design of Electron Gun for an X-ray Tube

Electron gun is a key part for all kinds of vacuum tubes, which is used to generate, accelerate and converge high energy density electron beam. In this paper, a three-pole electron gun for an X-ray tube is simulated and optimized. The goal for the design is to obtain an electron beam with small spot size, small divergence angle, high brightness and high anode current. By analyzing the effects of parameters including the filament-grid spacing, the thickness of grid, grid voltage and grid-anode spacing etc. on the trajectory and quality of electron beam, the relationship between optimization parameters and target parameters are given as well as the optimization results.