Simulation of W-band second-harmonic complex cavity gyrotron with abrupt transiton

By studying the cavity structure of a second-harmonic complex cavity gyrotron with abrupt transition, the modes competition and the interaction between the electron beam and wave, the characteristics of the RF structure, suppression of parasite oscillations and optimization of the work parameters are discussed. The simulation results of the low-loss TE02/TE03 low-voltage gyrotron are given. Using a gradient magnetic field in calculation, the interaction efficiency is significantly improved. PIC simulation results show that the gyrotron can generate 37 kW at 94 GHz with 37% efficiency with a 25 kV, 4 A and velocity ratio 1.6 beam.