A novel terahertz harmonic gyrotron with dual confocal cavity

A novel terahertz harmonic gyrotron with dual confocal cavity has been designed and simulated. The dual confocal waveguide is an improved confocal system to enhance beam-wave interaction efficiency. This terahertz gyrotron is designed to operate in the second harmonic of confocal TE0,11 mode. Particle-In-Cell (PIC) simulation results show that an output power of about 5 kW at 328.93 GHz can be generated when the gyrotron cavity driven by a 40 kV, 2A electron beam with guiding center radius of 1.65 mm and velocity ratio equal to 1.5. The interaction efficiency increases from 1.5% in single focal cavity to 6.2% in dual confocal cavity under the same operation parameters.