On the distribution of bound levels of ions in dense plasmas: The plasma polarization shift

We present a reconciliation of the null experimental observations with a proper statistical treatment of the plasma polarization shift, the density dependent shift of spectral lines which results from the differential screening of bound electron orbitals by penetrating, neutralizing free electrons in dense plasmas. It turns out that even at otherwise very high electron densities the mean number of perturbing free electrons within bound quantum orbitals of plasma ions is only fractional. Thus most radiators actually experience no perturbation and are expected to emit/absorb unshifted. On the other hand, the strength of the resulting central feature can be significantly reduced with respect to that of unperturbed radiators because of the power shifted into the dim red-side wing.