Ion drag force on a small grain in highly collisional weakly anisotropic plasma: Effect of plasma production and loss mechanisms

The ion drag force acting on a small absorbing grain has been calculated in highly collisional plasma with slowly drifting ions taking into account plasma production and loss processes in the vicinity of the grain. It is shown that the strength of the plasma production and loss mechanisms not only affects the magnitude of the ion drag force, but also determines the direction of the force. The parameter regimes for the "positive" and "negative" ion drag forces have been identified. In addition, the qualitative features of the electric potential distribution around the grain in isotropic conditions (in the absence of the ion drift) are investigated. (c) 2008 American Institute of Physics.