Use of weakly irregular waveguide theory to calculate eigenfrequencies, Q values, and RF field functions for gyrotron oscillators

The design of open resonators for gyrotron oscillators requires knowledge of the reso nator cigenfrequencies, Q values, and resonant RF field functions. These quantities can be obtained for open cavities with weakly irregular profile using the theoretical approach of Vlasov et al. which is based on the one-dimensional wava equation where / is the longitudinal variation of a TE or TM modo and β is the mode. propagation factor. In this paper we discuss the approximation.implicit in this approach and present a comparison of theoretical results and experimental data