Systematic Design & Analysis of a 42 GHz Gyrotron and the Effects of Structure & Beam Parameters on Its RF Performance

Abstract

The systematic design approach of a 42 GHz CW gyrotron has been extensively presented in this paper. Beam-wave interaction of the conventional tapered cylindrical cavity gyrotron is demonstrated using commercially available Particle-In-Cell (PIC) code. Beam absent and beam present cases have been considered to observe the performance of the device. Beam absent case is presented to validate the design in desired mode as well as resonant frequency whereas beam present case is demonstrated to validate and observe the beam-wave interaction behavior of the device in terms of output power. In order to optimize the dimension of interaction structure to achieve desired performance of the device, several parameters were considered. RF output power of the device is estimated with the variation of structure parameters as well as electron beam parameters to achieve better performance in terms of efficiency. Using the designed parameters, beam present analysis offers a saturated output power well above 250 kW. The particles phase space behavior along the interaction length is demonstrated to realize the energy transfer phenomena. The PIC simulation results are found in close agreement with the self-consistent single-mode results. The estimated output power and efficiency support the proper design of proposed gyrotron oscillator.