Structure of a source-driven magnetized oblique presheath.

Abstract

A source-driven magnetized presheath is analyzed in an obliquely incident magnetic field. The conventional fluid treatments of the collisionless and collisional magnetized presheath use standard fluid equations to recover the velocity profiles that satisfy the Bohm sheath criterion at the electrostatic sheath edge. In a purely source-driven collisionless presheath, however, there is no mechanism to redistribute the change in parallel energy in the perpendicular direction and therefore the boundary values of flow velocities are strong functions of angle of incidence. In the present treatment, numerical solutions are obtained for a set of fluid equations derived from the moment description of a generalized gyrokinetic equation. The density, velocity, and temperature profiles in a source-driven presheath are computed, which show a dependence on the angle of incidence of the magnetic field on a perfectly absorbing solid surface.