Density effects on electronic configurations in dense plasmas

We present a quantum mechanical model to describe the density effects on electronic configurations inside a plasma environment. Two different approaches are given by starting from a quantum average-atom model. Illustrations are shown for an aluminum plasma in local thermodynamic equilibrium at solid density and at a temperature of 100 eV and in the thermodynamic conditions of a recent experiment designed to characterize the effects of the ionization potential depression treatment. Our approach compares well with experiment and is consistent in that case with the approach of Stewart and Pyatt to describe the ionization potential depression rather than with the method of Ecker and Kröll.

Figure 1

Ionic fractions predicted by the average-atom model (AA), DFT, and HF approaches in an aluminum plasma in LTE at solid density and $T=100$ eV.

Figure 2

DFT and HF cumulative configuration occupation probabilities as a function of the ratio of the ground configuration energy ($E_{\text{ground}}$) on the excited configuration energy ($E_{\text{excited}}$) in an aluminum plasma in LTE at solid density and $T=100$ eV.

Figure 3

Ionic fractions predicted by the average-atom model (AA, square symbol) and HF (circle symbol) approaches in an aluminum plasma in LTE for the following mass density and temperature conditions: (a) 1.2 g/cc, 550 eV; (b) 2.5 g/cc, 650 eV; (c) 5.5 g/cc, 550 eV; (d) 9 g/cc, 700 eV.

Figure 4

Synthetic spectra for aluminum plasmas in LTE. From bottom to top, the thermodynamical conditions are 1.2 g/cc, 550 eV; 2.5 g/cc, 650 eV; 4 g/cc, 700 eV; 5.5 g/cc, 550 eV; and 9 g/cc, 700 eV.