Highly efficient generation of subnanosecond microwave pulses in Ka-band and nanosecond pulses in X-band

The paper presents theoretical and experimental studies of the Superradiance (SR) regime of short high-power microwave pulse production in the Cherenkov relativistic BWO. It was found in theory and simulations, that under certain conditions, the peak power of the microwave pulse may be higher than the electron beam power. It is possible for enough lengthy uniform slow wave structure in the case of moderate electron energy and task easy for longitudinal profiling of coupling impedance. In experiment using the RADAN-303SNS mini-accelerator, 420 MW, 200 ps pulses were produced in Ka-band. In X-band experiment using SINUS-150 accelerator, 1.2 GW, 0.5 ns pulses were produced with 140% power conversion efficiency.