K-shell photoionization of Na-like to Cl-like ions of Mg, Si, S, Ar, and Ca

TL;DR

This paper provides detailed R-matrix calculations of photoabsorption and photoionization cross sections near the K-edge for various ions of Mg, Si, S, Ar, and Ca, incorporating damping effects for plasma modeling.

Contribution

It introduces comprehensive R-matrix calculations including radiative and Auger damping effects for ions with over 10 electrons, enhancing plasma modeling accuracy.

Findings

Resonance profiles are symmetric with constant width due to damping.

Damping effects smear the sharp photoionization edge.

Data improve modeling of photoionized plasma features.

Abstract

We present $R$-matrix calculations of photoabsorption and photoionization cross sections across the K-edge of Mg, Si, S, Ar, and Ca ions with more than 10 electrons. The calculations include the effects of radiative and Auger damping by means of an optical potential. The wave functions are constructed from single-electron orbital bases obtained using a Thomas--Fermi--Dirac statistical model potential. Configuration interaction is considered among all states up to $n=3$. The damping processes affect the resonances converging to the K-thresholds causing them to display symmetric profiles of constant width that smear the otherwise sharp edge at the photoionization threshold. These data are important for modeling of features found in photoionized plasmas.