Investigation on Dual Frequency Operation in Double Confocal Gyrotron

Double confocal cavity shows good performance in high efficiency harmonic gyrotron development. Due to its specific configuration, dual frequency operation in double confocal gyrotron which has two different pairs of confocal mirrors is proposed. In this paper, the attempting of dual frequency operation in double confocal gyrotron is investigated by particle-in-cell simulation. A TE 0,8 fundamental and TE 0,15 second harmonic double confocal cavity is designed. In particle-in-cell simulation, both fundamental and second harmonic modes are stimulated simultaneously. The maximum 2.6 kW output power is observed, in which the power of fundamental TE 0,8 mode is 2 kW, and the power of second harmonic TE 0,15 mode is 0.6 kW. The results demonstrate that it is capable to generate dual frequency output at different harmonics by double confocal gyrotron.