A Gas-Discharge Vircator: Results of Simulation

Abstract

A gas-discharge magnetically insulated vircator containing two tubes, one of which is filled with low-pressure gas is proposed. Its particle-in-cell (PIC)/Monte Carlo (MC) simulation is carried out. The dynamics of free electrons, the dynamics of the virtual cathode (VC) as a whole, and gas ionization are calculated using the example of helium. It is shown that a squeezed state of the electron beam (distributed VC) arises in a gas-filled tube, effectively ionizing gas. It is found that at a pressure of helium of the order of several Pa, the degree of its ionization can reach several percent, which can be useful in creating a joint device “vircator-laser.” A high degree of ionization leads to charge and current compensation of the electron beam in the location of the squeezed state, and the distributed VC gradually dissolves. It is replaced by the two-beam state of the beam again, and repeated microwave generation, more powerful than in the vacuum case (the power increase is more than 6 times), occurs. In this case, the peak efficiency of repeated microwave generation reaches 15%. The frequency characteristics of the gas-discharge vircator which as it turned out differ insignificantly from the characteristics of the vacuum vircator were calculated.