Study an optical property of high current electron gun

Electron optics property of a high power electron accelerator (450kW) using the SLAC226 program was studied in this paper. Some results such as the potential distribution in the gun, the trace space plot of ray in anode plane, the impact on beam focusing caused by the spacing of diode were obtained. Through calculating, the best distance between anode and cathode is about 58.5mm. And some analysis of space-charge effects were also presented．