Wake effects of a stationary charged grain in streaming magnetized ions.

Abstract

A systematic numerical study of wake potential and ion density distribution of a single grain in flowing ions under the influence of a magnetic field applied along the flow is presented. A strong magnetic field introduces ion focus depletion behind grains, facilitating the entrance of electrons far in the downstream towards the grain. It is shown that the magnetic field suppresses the amplitude of the wake potential and modifies the ion density distribution substantially. The wake peak potential and position characteristics and density distribution of plasma constituents in the presence of a magnetic field and charge-exchange collisions for the subsonic, sonic, and supersonic regime are also delineated. In the subsonic regime, simulations demonstrate the accumulation of ions near the dust grain in the transverse direction, while complete suppression of oscillations in the transverse direction takes place for the sonic and supersonic regime.