Hybrid High-Power Multiple-Beam Generator With Double-Gap Coupling Resonator System

The results of numerical analysis of a new design of a hybrid powerful microwave generator based on a virtual cathode are presented. Its electrodynamic system is a double-gap resonator with seven transit channels where a multipath electron beam moves. The dimensions of the resonator were chosen in such a way as to provide a monotron effect in the in-phase mode. From an analysis of the Fourier spectra and phase portraits of the output signal oscillations, five characteristic generation regimes were revealed in the considered ranges of the induction of the focusing magnetic field and electron beam current. Oscillations close to single-frequency are observed in one of the regimes (regime A). In other regimes, chaotic oscillations are observed, which differ in spectral composition. From the particle-in-cell (PIC) simulation results, it follows that the generation in regime A occurs at a frequency of the in-phase mode and is characterized by high value efficiency. The maximum efficiency value of 13.6% was obtained with an electron beam current of 3 kA and a focusing magnetic field of 0.7 T.