Kinetics of Ionization-Recombination of a Plasma and Population Density of Excited Ions. I. Equilibrium Plasma

This is the authors' abstract. We don't add key points for this paper.

It is shown that ions in a low-density plasma has an excited-state population density described by corona equilibrium or by the capture-cascade scheme; for hydrogen-like ions both have the same p -dependence ( p is the principal quantum number) of n ( p )/ g ( p ) ∝ p -0.5 ( n ( p )/ g ( p ) is the population density per unit statistical weight) for an optically thin high-temperature plasma. For an equilibrium condition, relative contribution is about 10:1, verifying the corona model commonly assumed. For a low-temperature equilibrium plasma, however, the capture-cascade component dominates over the corona one for high-lying levels. In the high-density limit partial LTE holds only if the plasma is in ionization equilibrium or in complete LTE. In view of the fact that the equilibrium plasma is a rather exceptional case in actual situations, the theory is generalized: a plasma is decomposed into purely-ionizing- and purely-recombining-plasma components.