THE RECOMBINATION-DOMINATED POSITIVE-COLUMN WITH FINITE ION TEMPERATURE

This paper extends earlier work by including ion diffusion in the transport processes for both positive and negative ions in a positive column where negative ions dominate over electrons and ion-ion recombination is the dominant recombination process. As anticipated in previous work, the effect is to preserve the structure of a central negative ion-positive ion plasma core surrounded by an electron-positive ion plasma. Increasing tau, the ratio of ion temperature relative to electron temperature, results in a progressive smoothing of the previously sharp boundary. Introduction of another parameter tau means that the problem is effectively a triple eigenvalue problem with I = beta(i)n(e0)/upsilon(i) the ratio of central ion-ion recombination ratio to the ionization rate now being a function of tau. I is found to be a relatively weak function of tau, but the principal eigenvalue lambda is found to vary strongly with tau. An alternative method of approach using perturbation theory and tau as the variable for expansion is described and some results given to show consistency.