Wakefield excitation by a powerful sub-nanosecond 28.6 GHz microwave pulse propagating in a plasma filled waveguide

摘要

High-power microwave pulse generation (similar to 1.2 GW, similar to 0.4 ns, 28.6 GHz) by a super-radiant backward wave oscillator (SR-BWO) and the feasibility of wakefield-excitation with this pulse in a plasma-filled waveguide are presented. The SR-BWO is driven by an electron beam (similar to 280 keV, similar to 1.5 kA, similar to 5 ns) generated in a magnetically insulated foilless diode and propagating through a slow-wave structure in a guiding magnetic field of 8 T. The plasma produced by an array of flashboards filling a cylindrical wire-array waveguide attached at the exit of the SR-BWO is also characterized. 1D and 3D numerical simulations demonstrate that for the experimental parameters of the microwave pulse and the flashboard plasma filling the waveguide, a wakefield forms accompanied by significant periodic density modulations such that their radial location and depth can be controlled by the waveguide radius, plasma density, and microwave power. Published under license by AIP Publishing.