On the effect of the approximations used in gyrotron interaction calculations

Numerical simulations of the beam-field interaction in high-power gyrotrons are the basic tool for the design of the resonator in these devices. In the interaction codes, several assumptions are usually made in order to achieve fast simulations, which is a necessary feature of a designing tool. However, as the resonators get larger to meet the increasing needs in output power and, consequently, their mode spectrum becomes denser, the validity of some of the aforementioned assumptions needs to be revisited. We investigate the influence of these assumptions on the electron motion using pertinent numerical codes.