Influence of the Background Plasma on the Performance for X-Band Gyrotron Traveling Wave Tubes

Analysis of the performance for X-band continuous wave gyrotron traveling wave tubes (gyro- TWTs) with background plasma caused by residual gas ionization discharge is presented in this paper. The residual gas is released from the lossy dielectric ceramics during high average or continuous wave operation and ionized by colliding with the high-energy gyrating electrons. This results in a deterioration in the quality of the interacting electrons, which leads to a decrease in the output power and spectrum performance of the gyro-TWT. The collision of these ionized residual gas with gyrating electrons had been simulated based on a simplified model and the results such as electron beam characteristics, output power and spectrum are given and analyzed.