Numerical analysis of weakly relativistic large orbit gyrotron with permanent magnet system

High-harmonic gyro-devices with axis-encircling electron beams known as lar ge orbit gyrotrons (LOG) represent an appealing alternative to the conventi onal gyrotrons. In this paper we investigate the feasibility of such device operating with low current and low energy electron beams formed by a novel electron gun with a permanent magnet system. The results from the numerica l experiments indicate the possibility to excite TE41 mode at fourth harmon ic of the cyclotron frequency. Simulations predict generation of microwave radiation with frequency 104 GHz and output power near 1 kW.