Superradiance relativistic backward wave oscillator with high power conversion efficiency

Superradiance relativistic backward wave oscillator(SR-RBWO) with high power conversion efficiency is studied by simulation. Coaxial structure is used in the beam-wave interaction region. The outer conductor is a corrugated waveguide and the inner conductor is a smooth circular waveguide. Microwaves will be coupled to the circular waveguide and output from there. By increasing the period number and adjusting the corrugation depth near the collection end, the power conversion efficiency is improved furtherly. For an electron beam of 360 kV and 9.15 kA, with an applied magnetic field of 2.7 T, SR microwave pulse with 18 GW instantaneous power and 400 ps duration is obtained at a center frequency of 8.1 GHz by simulation, the power conversion efficiency reaches 275%.