Nonlinear Theory of Beam-Wave Interaction in Gyrotron Cavities with Gradual and Abrupt Transitions

Self-consistent nonlinear theory of beam-wave interaction in complex-shaped gyrotron cavities is developed. The theory combines the generalized telegrapher’s equations and mode-matching technique for gradual and abrupt transitions, respectively. As an example, a complex cavity of a second-harmonic 0.4-THz gyrotron is considered. For this gyrotron, the results of beam-wave interaction modeling are used as a check on accuracy of the simplified approach used in previous research.