THE CONTRACTED POSITIVE-COLUMN IN ELECTRONEGATIVE GASES

The theory of the positive column at moderate pressures in electron-attaching gases is examined for small attachment rates relative to the ionisation rate. It is shown that the negative (and positive) ions are confined to a channel in the centre of the discharge, by both computational and analytical approximation methods. Approximate expressions for the channel width and the eigenvalue which determines the electron temperature are derived. © 1990 IOP Publishing Ltd.