Theoretical analysis of a gyrotron driven by an external harmonic signal

In this paper, synchronization of a gyrotron by an external harmonic signal is analyzed based on a model with the Gaussian fixed structure of a high-frequency field using preliminary calculated complex gain factor. Stability conditions of the synchronization regimes with variation of beam current and cyclotron resonance mismatch are analyzed at different values of the driving amplitude. The dependences of the transversal efficiency (i.e., the portion of transverse energy given by electrons to the field) on these parameters are plotted. Optimal parameter values have been found at which, in the synchronization regime, an efficiency close to the maximal for an autonomous gyrotron is achieved, and a wide synchronization band is also ensured.