Design and verification of a wide range and high precision electron gun system

Abstract

BackgroundGrid-controlled electron guns mostly use mesh grid and extract pulsed beam current; there is little research on the wide-range direct current beam.PurposeThis study aims to design a wide-range high-accuracy direct current electron gun to meet the requirement of the Low Energy Electron Accelerator and Beam Line.MethodsBased on the original diode electron gun, a control grid was added to improve the control range and accuracy of the accelerator to form a triode electron gun. Then, the CST Particle Studio was employed to simulate the influence of some structural parameters of the triode electron gun on the extracted beam current, and obtained simulation result of electron gun was verified by Particle Beam GUN Simulation (PBGUNS) software. Finally, the experimental verification of design scheme was carried out on the electron gun experimental platform for optimizing the structure of electron gun. Several main structure parameters were changed to adjust beam current.ResultsThe experimental results show the optimized electron gun structure can extract 1 µA~50 mA high-quality beam when using cathode primary heating voltage as coarse adjustment and grid voltage as fine adjustment.ConclusionsThe influence law of gun structure parameters on beam current in the experiment is verify by simulation. The optimized gun structure meets the project requirements.

Keywords

• grid-controlled electron gun
• thermionic cathode
• direct current
• wide-range
• high-accuracy