PIC Simulation Studies of High Power RBWO with Trapezoidal Resonant Reflector at Low Guiding Magnetic Field

Abstract

In this paper, an S-band Relativistic Backward Wave Oscillator (RBWO) with Trapezoidal Resonant Reflector (TRR) has been studied at low guiding magnetic field by using 3D Particle-In-cell (PIC) code. The overmoded TRR and slow-wave structure (SWS) are more favourable in view of high-power handling capability under the low guiding magnetic field. In order to generate the GW level of power, the device is operated with ~1.2 MV of DC beam voltage and ~12.5 kA of developed electron beam current. The annular electron beam at the beam-wave interaction is guided by an external guiding magnetic field of 0.32 T. The PIC simulation predicted an average RF output power of ~5.0 GW at ~3.6 GHz in pure TM01 output mode with the conversion efficiency of ~34%. The obtained saturated RF power generation has been last up to 100 ns of simulation time without any pulse shortening. © 2020 IEEE.