A Single-stage Depressed Collector for a Gyro-TWA

In this paper, a single-stage depressed collector for a 263GHz, 1kW gyrotron traveling wave amplifier was designed and simulated using TRAK to recover the energy of spent electrons. The full position and velocity information of the spent electrons were exported after beam-wave interaction which was separately simulated using Particle-In-Cell simulation. A genetic algorithm based on MATLAB code was developed, combined with TRAK, to optimize the structure of the collector for maximum collection efficiency. A collection efficiency of 87.1% was achieved and the result was verified by CST Particle Studio.