Coaxial-Type Magnetically Isolated Relativistic Vircator

A coaxial-type magnetically isolated relativistic vircator was simulated by the particle-in-cell method. It is shown that, after the creation of a virtual cathode in the second vircator tube, a squeezed state of the electron beam is established in the first vircator tube, which represents a one-component hot electron plasma with an electron density of n ≅ 1.4 × 10 11 cm –3 and a temperature of 50 keV; the plasma formation time is 125 ns. The microwave characteristics of the vircator were calculated. The peak microwave power generated during the first 100 ns (the peak efficiency is ~17.5%) was found to be ~1.4 GW and, after the squeezed state is established, the generation power decreased to an average value of ~250 MW (the average efficiency is ~3%). A spectrogram of the radial component of the electric field in a coaxial line was calculated. It was observed that the oscillation frequency increases during the first 100 ns and then remains unchanged at a level of GHz.