Stabilization of Absolute Instabilities in the Gyrotron Traveling Wave Amplifier

Abstract

Absolute instabilities in the gyrotron traveling wave amplifier are investigated with a simulation approach which models electron and wave dynamics in the sever and distributed-loss section. Distributed wall losses are shown to be far more effective than the sever in stabilizing these instabilities. Physical interpretations are given and theoretical predictions are verified by a ${K}_{a}$-band experiment which achieved 62 kW peak power with 12% bandwidth, 21% efficiency, and 33 dB saturated gain through the use of a mechanically adjustable magnetron injection gun.