The Grouping of Electron Flow in Three-Gap Resonator at Excitation of Highest Mode with Multiple Frequency

The results of a three-dimensional simulation of the electron flow grouping in a three-gap resonator are presented. By means of the change in the sizes of the coupling slots between the resonance cavities, the resonator can be tuned in such a way that the ratio of the frequency f2 of the second higher mode (in-phase) to the frequency f1 of the main mode (anti-phase) becomes equal to two. It is shown that when the input signal is fed at a frequency f1 (when f2/f1 = 2), the in-phase mode of oscillation is excited in the resonator, the amplitude of the oscillations that exceeds the amplitude of the main mode oscillations. In this case, the repetition frequency of the electron bunches at the exit from the resonator doubles.