Generation of a sequence of powerful ultrashort microwave pulses based on the effect of superradiance of a relativistic backward-wave oscillator with reflectors at the ends of the interaction space

In a numerical experiment based on nonstationary codes, it is shown that introduction of reflections at the ends of the slowing structure of a relativistic backward wave oscillator operating in the superradiance mode provides conditions for the formation of a sequence of powerful ultrashort microwave pulses during a single current pulse. The pulse repetition frequency is specified by the time of propagation over the feedback circuit and can amount to $\sim$100 MHz. The conversion factor defined as the ratio of the peak power of the ultrashort pulse to the electron beam power is about 3 for the first (main) pulse and decreases to $\sim$2 for subsequent pulses.