Control of electrostatic charging of solids in channels filled with electron beam plasma

Electrostatic charging of macroscopic solids placed in a cylindrical channel filled with cold strongly nonequilibrium plasma is experimentally studied. Plasma is generated by injection of a thin electron beam along the channel axis. Air, oxygen and noble gases are used as plasma-generating gases. The value of the potential of bodies of the simplest geometry (sphere, disk) is measured relative to the grounded parts of the experimental setup; the experiments are carried out in both stationary plasma and plasma flows. The value of the charge accumulated by solids is found to depend on the chemical composition and pressure of the plasma-generating gas, the power of the injected electron beam and the plasma flow velocity, and on the angle of the electron beam incidence on the surface (for bodies in the form of a disk).