Effective radiative cooling in optically thin plasmas

Abstract

We present the radiative cooling rates and cooling timescales of an optically thin atomic gas for the temperature range 10 2 K to 10 9 K, calculated in a thermally self-consistent, time-dependent approach. The most important emission lines of the ten most abundant elements have been considered as well as the relevant continuum processes. We compare the cooling rate of a gas in collisional ionization equilibrium with those of gases with nonequilibrium ionization. We also compare the time-dependent ionization states of all considered elements with those of steady-state calculations. Time-dependent ionization stages, cooling rates and timescales are influenced by the previous history of the gas and by the thermodynamical path (e.g., isochoric or isobaric) of cooling