Thermal Analysis of Magnetron Injection Gun for 170GHz Gyrotron

The 170GHz gyrotron presented in this paper has an operating voltage of 75kV and a beam current up to 45A, which requires the cathode emission temperature to reach above 1000 °C. At such a high temperature, thermal expansion of the electron gun is bound to occur. In this paper, ANSYS Workbench and COMSOL Multiphysics were used to conduct a thermal analysis of the electron gun. According to the analysis results, the filament power, number and position of the electron gun structure were optimized to meet the design requirements. The maximum value of the total deformation of the overall structure of the electron gun is about 0.06mm, and the total deformation of the cathode emission belt is about 0.054mm. Besides, the thermal analysis results obtained by the two software are compared; the simulation results agree well. The deformation is within the acceptable range, which has little influence on the performance of the electron gun.