Overview of the inner-subshell excitations <em>n</em><sub>0</sub><em>l</em><sub>0</sub> → <em>nl</em> included in the present calculations

<p><b>Table 2.</b> Overview of the inner-subshell excitations <em>n</em><sub>0</sub><em>l</em><sub>0</sub> → <em>nl</em> included in the present calculations. All subshells with quantum numbers <em>nl</em>, where <em>n</em> ≤ <em>n</em><sub>max</sub> and <em>l</em> ≤ <em>l</em><sub>max</sub>, providing at least one vacancy to which the <em>n</em><sub>0</sub><em>l</em><sub>0</sub> electron can be excited were considered. The orbital quantum numbers <em>l</em><sub>0</sub>, <em>l</em><sub>max</sub> = 0, 1, 2, ... are expressed by their spectroscopic symbols s, p, d,..., respectively. For ions in the ground-state configuration, <em>m</em> is the number of electrons in the 4d subshell. It is equal to 10 for Sn<sup>4 +</sup> and 1 for Sn<sup>13 +</sup>. As far as long-lived excited ions are concerned, we only had to consider 4d-subshell-excited configurations for the charge states up to <em>q</em> = 12. In the configurations of interest, the 4d subshell is initially populated with <em>m</em> − 1 electrons and the excited electron is initially in subshell <em>n</em><sub>1</sub><em>l</em><sub>1</sub>. The subshells <em>n</em><sub>1</sub><em>l</em><sub>1</sub> taken into account in the present analysis are listed in table <a href="http://iopscience.iop.org/0953-4075/46/17/175201/article#jpb473129t1" target="_blank">1</a>. For the case of Sn<sup>13 +</sup>, the only excited configuration of relevance to the present measurements is the 4p<sup>5</sup>4d<sup>2</sup> configuration.</p> <p><strong>Abstract</strong></p> <p>Electron-impact single-ionization cross sections of Sn<sup><em>q</em> +</sup> ions in charge states <em>q</em> = 4–13 with 4d<sup>[10 − (<em>q</em> − 4)]</sup> outer-shell configurations have been studied in the energy range from the corresponding thresholds up to 1000 eV. Absolute cross sections and fine-step energy-scan data have been measured employing the crossed-beams technique. Contributions of different ionization mechanisms have been analysed by comparing the experimental data with calculations employing the configuration-averaged distorted wave approximation. Ionization plasma rate coefficients inferred from the experimental data are also presented.</p>