Statistical treatment of radiative transitions in local thermodynamic equilibrium plasmas

The fluctuations of the electronic configurations around the average-atom configuration are estimated using classical statistical mechanics. This method allows the spectral opacities to be rapidly calculated without explicit recourse to detailed configuration accounting. Coupled to a screened-hydrogenic average-atom model, it can be implemented into the atomic physics package of a hydrodynamic code. We compare our results to numerical spectra constructed with more detailed codes or experimental spectra. {copyright} {ital 1997} {ital The American Physical Society}