Design of a 300 GHz Relativistic Gyrotron with an output Power of more Than 7 MW

Calculations are presented for an electron-optical system that makes it possible to produce a helical electron beam with an energy of 250 keV, a current of 100 A, and a pitch factor of 1.1 for a 0.3 THz gyrotron with the operating mode of TE33.2. Based on averaged stationary equations with a non-fixed field structure, the cavity profile is optimized and the possibility of obtaining an output power of about 8 MW with an electronic efficiency of more than 30% is demonstrated. Within the framework of particle-in-cell three-dimensional simulation, the processes of establishing oscillations are considered. Besides, it is shown that in the range of magnetic fields from 14.7 to 15.1 T, selective excitation of oscillations in the operating mode with a maximum power of about 7 MW is possible.