Redistribution of resonance radiation in hot and dense plasmas
Résumé
A method for calculating the redistribution of resonance radiation in hot, dense plasmas is developed by extending the frequency fluctuation model (FFM). This model was originally designed as a numerical procedure for the calculation of the spectral shape of Stark-broadened lines emitted by multielectron ions and has been particularly useful in computations accounting for the ion dynamics effect. The FFM is based on a numerical technique that replaces the primitive inhomogeneous Stark component contributions to the linear response line shape with the observable radiative channels. These channels can be viewed as equivalent to a system of microfield dressed two-level radiators, the Stark-dressed transitions (SDT), which emit a set of spectral lines that reproduce the main features of the first-order radiative properties of the emitter. The mixing of these transitions through a stochastic process is equivalent to random fluctuations of the local ion microfield. The SDT form the basis for the extension of the FFM to the computation of nonlinear response functions. The theory of the second-order radiative redistribution function is reviewed and examples are given. [S1050-2447(99)08008-7].