Time-domain PIC-modeling of suppression of self-modulation in the multiple cavity klystron oscillator with delayed feedback

The results of time-domain PIC-modeling of suppression of self-modulation in a four-cavity klystron oscillator with external delayed feedback are presented. The method is based on using an additional feedback loop with properly chosen delay and phase shift. The application of the method increases the self-modulation threshold beam current. This results in significant increase of the output power and efficiency in comparison with the oscillator with a single feedback.