EFFECTS OF VARIOUS FORCES ON THE DISTRIBUTION OF PARTICLES AT THE BOUNDARY OF A DUSTY PLASMA

The distribution and suspension of dust particles under the action of electrostatic, gravitational, ion-drag and neutral collision forces ar e investigated near the boundary of a dusty plasma. It is shown that t he competition among the forces results in spatial oscillations (multi -layer) of the particle distribution. For sub-micron grains the ion-dr ag has a significant effect on the grain dynamics while for micrometer sized grains the gravity quickly dominates over other forces. The eff ect of the neutral gas flux is to enhance or diminish that of the grav ity while the effect of the neutral viscosity is to shift the profile toward the wall. Under the force balance, the particles are suspended in a narrow region with sharp boundaries within the sheath. (C) 1997 A merican Institute of Physics.