Simulated behavior of planar-helix slow-wave structure traveling-wave tube at various electron beam current

Planar-Helix Slow-Wave Structure (PH-SWS) possesses promising potential in the miniaturization of Traveling-Wave Tubes (TWTs). To utilize this design, understanding in the effect of beam current on the operation of PH-SWS TWT is needed. In this study, we have performed PIC simulation on the reported PH-SWS TWT at various beam currents. From the simulation results, it is found that PH-SWS TWT experiences saturation in signal gain as the beam current reaches 25 mA. At the same time, electron collision on PH-SWS occurs when the beam current exceeds 20 mA.