A high power 390 GHz harmonic gyrotron based on cusp electron gun

The design and simulation of a harmonic gyrotron based on a cusp electron gun is presented. The gyrotron is operated at the 7
^th
electron cyclotron harmonic with an output frequency of ~390 GHz and mode pattern of TE
₇₁
. A large orbit electron beam with energy of 40 keV, beam current of 1.5A and an adjustable pitch alpha from 1 to 3 from a cusp gun is used to drive the beam-wave interaction. Smooth cylindrical waveguide and slotted structures have been studied as interaction cavities. Theoretical analysis and numerical simulation results of these structures will be presented.