The plasma wake of mesosonic conducting bodies. Part 2. An experimental parametric study of the mid-wake ion density peak

Abstract

An experimental investigation of the disturbed flow field created by conducting bodies in a mesosonic, collisionless plasma stream is reported. Part 1 dealt with ion focusing by the body's plasma sheath and the subsequent filling of the near-wake void region. In part 2, the mid-wake region is investigated, where, for bodies of the order of a Debye length in size, the focused ion streams converge to form a significant current density peak on the wake axis. A parametric description is obtained of the behaviour of the amplitude, width, and position of this peak. The results also indicate that portions of the axial ion peak are created by additional mechanisms and that body geometry affects the mid-wake structure only when the sheath is sufficiently thin to conform to the shape of the body.