Comparison of PI cross sections between the present results and the available theoretical and experimental data for Ar<sup>8+</sup>

<p><strong>Figure 1.</strong> Comparison of PI cross sections between the present results and the available theoretical and experimental data for Ar<sup>8+</sup>. (a) Our results from DARC; (b) the convoluted results of DARC (black line), our MCDF results (blue vertical lines with circles), and those calculated by Simon <em>et al</em> (red vertical lines with diamonds) using a Gaussian profile of FWHM = 800 meV, and the results from TOPbase [<a href="http://iopscience.iop.org/0953-4075/46/17/175402/article#jpb467372bib2" target="_blank">2</a>] (magenta dotted line) convoluted with FWHM = 300 meV; (c) overview of experimental PI spectrum of the Ar<sup>8+</sup> ion [<a href="http://iopscience.iop.org/0953-4075/46/17/175402/article#jpb467372bib21" target="_blank">21</a>].</p> <p><strong>Abstract</strong></p> <p>Photoionization (PI) cross sections of the ground state 1s<sup>2</sup> 2s<sup>2</sup> 2p<sup>6</sup><sup>1</sup> S<sub>0</sub> of Ne-like Ar<sup>8+</sup>, Fe<sup>16+</sup>, Kr<sup>26+</sup> and Xe<sup>44+</sup> ions are calculated by using the Dirac atomic <em>R</em>-matrix code based on a fully relativistic <em>R</em>-matrix method. To analyze the detailed resonant structure, systematical calculations based on the multiconfiguration Dirac–Fock method are performed for the dominant 2s → <em>n</em>p resonant transitions, and the resonant energies, strengths and total natural widths are presented. The resonant structures and characteristics of the PI cross sections and resonance strengths along the Ne-like sequence are discussed with emphasis on the influence of relativistic effects. For the Ar<sup>8+</sup> ion, good agreement is found between the present results and available theoretical calculations and experimental data.</p>