NLTE emissivities via an ionisation temperature

We present recent work aimed at obtaining opacities and emissivities in NLTE plasmas, at sufficiently low cost to be used in-line by hydrodynamics codes. We try to improve the basic ingredients of the RADIOM model, namely the ionisation temperature T-Z and the source function. The accuracy of the estimated T-Z is tested by comparing the resulting ionisation curves to some submitted to the 1996 NLTE Kinetics Code Comparison Workshop. We examine the quality of the source function by comparing the emission spectra to some recent results from average-atom, detailed configuration and superconfiguration codes.(C) 2001 Elsevier Science Ltd. All rights reserved.