Numerical Modeling of the Processes of Electron-Wave Interaction in the Cavities of High-Power Gyrotrons with a Frequency of 300 GHz

Abstract

Some of the intended fusion experiments and promising technological applications require sources of microwaves with powers of about 200-1000 kW in the continuous-wave regime at frequencies of 300 GHz and higher. In the process of project accomplishment, we studied the interaction of a helical electron beam with the high-frequency field in the cavities of several design versions of such gyrotrons for operation in the continuous-wave regime. Main issues have been identified and possible solutions have been considered.

Concept design of the megawatt power level gyrotron stabilized by a low-power signal for DEMO project

“…Numerical simulation of the wave-beam interaction to obtain the efficiency and output power was performed in the framework of the single-mode self-consistent model [13,14], which takes into account the cavity profile, Ohmic losses, spread of electron transverse velocities, and other factors. With an increase of the radiation frequency, the effects of mode transformation at the irregularities of the electrodynamic system begin to play a significant role [14]; therefore the output part of the cavity was additionally optimized in order to achieve a minimum transformation of the operating mode into others. The calculated mode purity of the operating mode outside the cavity in the output waveguide is 99.9%.…”