The formation of a plasma sheath.

In this paper we consider how the electric potential varies in space and time during the formation of a plasma sheath. We give the variation of the wall potential in time, the potential profile at various stages of the sheath formation and the variation of the total current at the wall.
In this paper we extend the well-established static theory of plasma sheaths and discuss the growth of a sheath near a plane perfectly absorbing wall. Suppose that we introduce a plane perfectly absorbing sheet of material into a plasma which is electrically neutral and consists of electrons and a single type of singly ionized atoms. The mobile electrons will in general have a much higher velocity than the more massive ions and so initially more electrons than ions will strike the wall, and be absorbed, per unit time. Thus the wall will initially acquire a net negative charge. This charge will repel the electrons approaching the wall from the main body of the plasma and attract the ions. The net charge on the wall will continue to increase until the current density at the wall becomes zero. We wish to investigate the rate of growth of the potential of the wall and the profile of the electric potential at any time on the basis of a simple model. [ABSTRACT FROM AUTHOR]