A Compact Relativistic Magnetron with Extract Ring

Over the past decades, the compactness of high-power microwave (HPM) sources has emerged as a pressing concern. Among these, the relativistic magnetron (RM), a well-established HPM source, stands out due to its simplicity, compact design, exceptional beam-wave interaction efficiency, and low applied magnetic field requirements. In this paper, we introduce a compact S-band ring-extraction RM, boasting an output radius of just 41.1 mm, making it suitable for permanent magnet packaging. Based on three-dimensional particle-in-cell (PIC) simulations, our device, operating at an accelerator voltage of 400 kV and an applied axial magnetic field of 0.55 T, is capable of delivering an output power of 0.77 GW at 3.16 GHz, achieving a remarkable power conversion efficiency of 54%. This promising device holds significant potential for use in compact HPM systems.