Design of 42 GHz gyrotron for Indian fusion tokamak system

•The complete electrical design of 42 GHz, 200 kW gyrotron is presented.•Un-depressed collector and axial output system for RF power is selected.•Various commercially available design tools as well as in-house developed computer codes are used in the design process.•The experimental results of cold cavity analysis are also presented.•The design results show more than 200 kW power with 40% interaction efficiency at 42 GHz frequency.

In this paper, the complete design of a 42 GHz, 200 kW gyrotron at first harmonic operation for Indian tokamak system is presented. The gyrotron is designed for TE0,3 operating mode. Un-depressed collector and axial output system for RF power is selected just due to the sake of simplicity in the actual fabrication of the device as it is the first design and development experience. Various commercially available design tools as well as in-house developed computer codes are used in the design process. The experimental results of cold cavity analysis are also presented in this manuscript. The rigorous design simulations confirm more than 200 kW RF power generation in TE0,3 mode at 42 GHz frequency.