Design of 120GHz, 1MW Gyrotron for Plasma Fusion Application

In this article a complete design of the gyrotron is presented. Considering the goal of 1MW power and 120GHz frequency, flrst the mode selection and the interaction cavity design are performed. The high order asymmetric mode TE22;6 is selected as the operating mode by using the mode selection code GCOMS. The interaction cavity geometry is calculated on the basis of selected operating mode and Particle-in-Cell (PIC) code is used for the beam-wave interaction computation and power and frequency growth estimation. The electron beam source (generally called Magnetron Injection Gun, MIG) is designed by using the EGUN and TRACK codes. The spent electron beam energy is collected at the specially designed cylindrical waveguide type of structure called collector. For the 120GHz gyrotron, single stage depressed collector is designed to improve the e-ciency considering the maximum beam spread at the collector wall. Finally, the RF window is designed for the efiective transmission of the generated RF power. The overall design data shows the 1MW power generation at 120GHz frequency.