The shielding of dust particles by each other in a dusty plasma is studied taking into account the effects of dust charging. It is shown that the assumption of a Boltzmann response for dust species is not appropriate under these circumstances. Further, it is shown that in the close-packing limit, dust grains screen each other by charge reduction, and an expression is obtained for this shielding...

The phenomenon of centrifugal separation in a rotating multispecies plasma column is discussed. Rate equations for collisional separation are derived. Two electrostatic instabilities that are driven by centrifugal effects are also considered: a diocotron mode and a drift wave.

The role of atomic, molecular and plasma wall interaction processes in divertor plasmas of magnetic fusion devices is briefly outlined. Some critical issues in the atomic physics and plasma wall interaction databases, which determine the accuracy and predictive capabilities of divertor plasma modeling codes, are discussed in more detail.

The control of tokamak fusion experiments is outlined with particular reference to the evolution of the control from primitive pre-programmed operation, through to feedback control of many parameters, finally developing advanced methods which are destined to optimise the performance of the tokamak plasma. Four examples of enhanced control of tokamak plasmas are given.

A summary of the Workshop on Non-neutral Plasmas, held in Boulder, Colorado, on July 29 through August 1, 1997, is given. This workshop provided an opportunity for the exchange of results and scientific information among the diverse areas of plasma physics, atomic physics, and chemistry, which use non-neutral plasmas.