On the Ion Flux From Beam Plasma to a Metal Target Irradiated by a Pulsed Electron Beam in the Forevacuum Pressure Range

We describe our investigations of the influence of electron beam parameters and working gas on the ion flux coming from the beam-produced plasma (beam plasma) to a target irradiated by a pulsed low-energy (up to 9 keV) electron beam in the forevacuum pressure range 4-15 Pa. The ion current from the beam-produced plasma to the target increases with increasing gas pressure and beam current, but decreases with increasing beam accelerating voltage. The use of gas with a greater ionization cross section leads to greater ion flux and correspondingly higher ion current to the irradiated target. The value of ion current to the target from the beam-plasma does not exceed 20% of the electron beam current. The observed dependencies of ion flux (current) to the target are due to changes in the beam-plasma density near the target. These results contribute to our understanding of the generation of beam-plasma by a pulsed electron beam and suggest the application of the ion flux from the beam-plasma to assist in electron-beam modification of dielectric materials in the forevacuum pressure region.