Simulation of the Gyrotron with an Arbitrary Cross Section of the Cavity Resonator and a Fixed Longitudinal Field Structure

We present the averaged gyrotron equations derived within a model with a fixed longitudinal field structure and an arbitrary cross section of the cavity resonator. The presented set of equations allows one to describe and simulate the dependences of the starting currents and the electronwave interaction efficiency on the parameters of the electron beam and the characteristics of the electrodynamic system in promising gyrotrons having resonators with improved mode selection. A gyrotron with an operating frequency of 263 GHz based on a two-mirror confocal resonator with cylindrical mirrors is considered as an example.