Spectral line broadening of H- and He- like Si IONs in hot and dense plasmas

Summary form only given. The use of high-Z element traces in dense and hot plasmas is a valuable technique for diagnosing the plasma properties. In this work, we present Stark-broadened profiles of spectral lines of H- and He-like Si ions, assumed to be immersed into a CH₂-foam plasma, as is used, for example, in hohlraum experiments. The line shapes are calculated for the range of plasma densities and temperatures that are relevant for these traces, i.e., N _e = 3times10²¹-3times10²² cm^-3 and T_e=T_i=100-2000 eV. By using a recently developed method, the line shapes are calculated with a high accuracy, accounting for ion dynamics, plasma correlation effects, and interactions between the radiators and the plasma particles. The degeneracy-breaking effects, including the spin-orbit interactions, are taken into account rigorously. Both the core and the far wings of the line profiles are analyzed, and density and temperature dependences are investigated. It was found that in cases when the radiator can be considered as a mostly degenerate system, the line-width dependence on the density is close to ~N_e ^2/3, and the temperature dependence is rather weak, while e.g. the spin-orbit interaction makes the picture more complicated. In addition, the ion-dynamics and correlation effects are proven to affect the line broadening significantly. A semi-empirical model is suggested for an accurate and easy-to-use approximations of the line shapes, for the entire region of plasma parameters considered