Nonlinear simulation on 3 mm band second-harmonic complex cavity gyrotron with gradual transition

Starting from general transmission line equation with an electron beam, a self-consistent nonlinear analysis on 3 mm band second-harmonic complex cavity gyrotron with gradual transition is presented, in which the multiple mode interacting with a electron beam and mode coupling are taken into account, through a simulation code of self-consistent nonlinear beam-wave interaction made by ourselves. The influences of the magnetic field coefficient and current and the velocity ratio of the electron beam under the interaction between the electron beam and H02-H03 RF field for second-harmonic gyrotron are analyzed. The results show that an electron efficiency over 27% is predicted for suitable dimensions for the complex cavity and magnetic field coefficient and current and the velocity ratio of th