Scattering of relativistic electron beams by the anode mesh in high-current vircators

Abstract

In a virtual cathode oscillator, the scattering of a high-current relativistic electron beam by the anode mesh leads to formation of an electron cloud near the anode. The cloud particles possess low energy and large spread in velocities caused by multiple scattering and ionization losses. The electrons captured by the cloud do not participate in the oscillations of the virtual cathode and partially block a vircator. As a result, the amplitude of the electric field oscillations is reduced. In order to increase the oscillation amplitude, the thickness of the anode mesh should be equal to the mean free path for electrons in the mesh material.