Efficiency Study of a Terahertz-Range Gyrotron

This study is part of an effort toward designing a 300 kW gyrotron oscillator operating at 670 GHz. Three configurations of cavities designed for operation at the TE31,8 -- mode were considered. Cavity design studies have been performed by using the self-consistent code MAGY, with the account for ohmic losses and velocity spread. It was found that the maximum efficiencies in these three cavities reached 23{\%}, 34{\%} and 35{\%}, respectively. Details of calculation will be presented at the meeting.