Particle-in-cell simulation of the third harmonic cavity F-Tube klystron

Use of a second harmonic and third harmonic cavity within a klystron to increase efficiency has been studied using particle-in-cell (PIC) code, MAGIC 2D. The six cavity device has a drive frequency of 1GHz, a predicted efficiency of 88%, 39 dB gain and an output power of 833 kW. The preliminary simulation results have revealed indications of bunching with bunch core oscillations. The initial results and analysis of the F-Tube PIC study are presented.