Polarization force on a charged particulate in a nonuniform plasma

The force on a charged particulate or ``dust grain'' in a plasma is derived in the presence of a density gradient and an externally applied electric field. The Debye sheath around the particulate is usually deformed (i.e., polarized) under such conditions, and exerts a force on the particulate. This sheath-polarization force is always in the direction of decreasing Debye length, regardless of the sign of the particulate charge. The magnitude of the polarization force is estimated under typical glow discharge conditions.