Relativistic backward wave oscillator using a selective mode converter

A new version of the relativistic backward wave oscillator (BWO) is proposed and investigated experimentally, where the cutoff (for the working mode mode) taper at the cathode end is replaced by a selective Bragg-type mode converter. In the experimental BWO model, which operates in the three-centimeter range and is equipped with a mode converter based on a slightly corrugated waveguide, a radiated power of 700 MW in pulses of duration up to 100 ns with an output spatial structure similar to a Gaussian wave beam is obtained at an accelerating potential of 0.8 MV and a focusing magnetic field of 7 kOe. Zh. Tekh. Fiz. 69, 102–105 (November 1999)