Simulation and experimental study on the beam extraction of ion bombardment secondary emission electron gun
To meet the demand of electron beam fluorescence technology for electron guns,this paper performed the research on ion bombardment secondary emission electron guns.The working principle of ion bombardment secondary emission electron gun was firstly introduced.The working process was divided into two parts:ion generation and extraction,and Secondary electrons generation and extraction.A simplified air discharge simulation model was established based on the principle of glow discharge.The density and distribution of positive ions were obtained using Comsol software.For the emission process of secondary electrons in the acceleration chamber,the electron beam was focused by electrostatic focusing.The best structural parameters of Secondary electrons extraction were obtained by using Comsol software based on Nelder Mead algorithm.Finally,an electron gun prototype was constructed.The experimental result showed that the positive ions produced by air discharge bombarded the metal aluminum to make it emit Secondary electrons.An electron beam with an acceleration voltage of 20 kV and a beam intensity of 1.6 mA was obtained.This work confirmed the principle of electron gun and laid the foundation for performance improvement.
electron gunion bombardment secondary electron emissiongas dischargeelectron beam fluorescence measurement
万方数据
维普
