Reduced models of the dynamics of light impurity stripping

"Closed" and "open" reduced models of two or three most abundant light impu rity ions in an optically thin hydrogen plasma are considered. The models a re shown to satisfactorily describe the average ion charge and radiative lo sses within a wide range of parameters typical of laboratory and astrophysi cal plasmas, including the case when the relaxation time of the impurity di stribution over ionization states is comparable to or longer than the chara cteristic times of the most important dynamic processes. The potentialities of the models are demonstrated using the carbon impurity as an example. Th e models proposed make it possible to analytically study the dynamics of a radiating plasma, obtain qualitatively new results, and significantly reduc e the computation time when solving complicated self-consistent dynamical p roblems. (C) 2001 MAIK "Nauka/Interperiodica".