Bunching Parameter Study of Hybrid Gyrotron Amplifier

Abstract

The performance of multistage gyrotron amplifiers depends upon the prebunched electron beam, which is evaluated by the bunching parameter. In hybrid gyrotron amplifier named gyro-twystron, electrons are modulated in the cavity and get ballistically bunched in the drift tube. The prebunched electron beam interacts with RF wave in the output waveguide. In this paper, the bunching parameter dependency on Prebunching RF structure dimension is investigated and further analysed to optimise the transverse efficiency. The analysis predicted the transverse efficiency of 50% is achieved at the bunching parameter of 1.88 and produces an output power of 12.5 kW. 3D particle-in-cell (PIC) simulation of two cavity gyro-twystron has been done to validate analytical results, and PIC simulation predicted an output power of 11.5 kW. © 2020 IMA-Institut fur Mikrowellen-und Antennentechnik e.V.