Particle simulation of relativistic backward wave oscillator with coaxial extractor

An L-band relativistic backward wave oscillator with coaxial extractor is investigated using the KARAT 2.5 D particle simulation code. Detailed beam-wave physical interaction in the oscillator are presented. Typical simulation results are that, under the magnetic field of 1.0 T, an L-band microwave with an average output power of 2.2 GW is obtained for 700 keV/10 kA electron beam, and the efficiency is over 30%. The optimized electromagnetic structure of the device is Φ100 mm×520 mm.