An alternative method to determine atomic radiative emission

Université de Provence et CNRS, UMR 6633, Centre de St-Jérôme, PIIM F-13397 Marseille Cedex 20, France

Received: 30 May 2006
Accepted: 19 October 2006

Abstract

We reconsider the standard paradigm that detailed spectral distributions must be determined by the inclusion of detailed atomic and ionic level structure in the population kinetics. An alternative method is proposed which creates detailed spectra from a reduced description of the level-population kinetics. The method is based on the introduction of a non-LTE effective population-density coefficient that corresponds to a redistribution of the population with respect to the strengths of various excitation channels. An analytical solution that is based entirely on the reduced level-population kinetics is derived, which reduces the computational effort in the standard paradigm by orders of magnitude. Exact numerical calculations show excellent agreement, even for non-Maxwellian and non-equilibrium plasmas.