Model calculations of the interaction of a diffusing BaO cloud with an infinite conductivity Ba+ plasma cloud have been performed. This diffusing neutral cloud initially structures the ion cloud preferentially at long wavelengths for values of the ionized cloud radius &rgr;0, neutral cloud Gaussian radius a, and separation rl between ionized and neutral cloud centers such that &rgr;0rl/a2≲1. In the plane perpendicular to the ambient magnetic field B the phase of the distortions in the Ba+ cloud is such as to produce 'dimplings' of the field line integrated isodensity Ba+ contour at radius &rgr;0, i.e., to produce displacements radially inward toward the field line integrated Ba+ cloud center at both points where the line passing through the two cloud centers intersects the circle of radius &rgr;0 centered at the origin of the Ba+ cloud. The amplitud e of the displacements is greatest for &rgr;/a?1, rl/a?1. The inward displacements can be as large as 0.015a. For &rgr;0=a this could result in dimplelike displacements of characteristic size &rgr;0 in times of ~4&rgr;0/Vdr, where Vdr is the magnitude of the relative ion-neutral drift velocity in the striating region. Computer simulation results supporting these ideas are shown. Moreover, the theoretical model and attendant numerical results are in general agreement with observations of a 144-km Ba cloud released in the Secede test program. |