RF behavior and cavity design for 0.3 THz, 4 kW gyrotron for material processing application

The design of weakly tapered interaction cavity for 0.3 THz, 4 kW gyrotron operating at the fundamental cyclotron harmonic is presented in this paper. The interaction cavity design and the beam-wave interaction computation are carried out for TE0,6 mode by using the Particle-in-Cell (PIC) electromagnetic simulation approach. The operating mode is selected by using the code GCOMS, in which various mode selection parameters and start oscillation current are calculated. Further, the power and frequency estimation are performed to finalize the cavity and electron beam parameters. The sensitivity analysis is done to finalize the tolerance limit in various parameters. Finally, the thermal and structural analyses are performed for the designed interaction cavity for the effective cooling.

► PIC numerical approach is used for beam-wave interaction and cavity design.
► TE0,6 is selected as operating mode as it satisfies all mode selection criteria.
► The interaction efficiency is 22% without depressed collector.
► Sensitivity analysis of beam parameters is carried out.
► Thermal and structural analysis of the cavity is carried out by using ANASYS.