Electron-ion collision is one of the fundamental processes in atomic and molecular physics, and the study of this process can provide insight into the mechanism of electron-atom/ion interaction. It has important applications in plasma physics and astrophysics. Accurate electron-impact cross-sections are important in plasma modeling. In general, total electron impact single ionization (EISI) cross-section is contributed from the direct ionization (DI) and the indirect ionization processes, with the latter further divided into excitation auto-ionization (EA), resonant excitation double auto-ionization (REDA), and resonant excitation auto-double ionization (READI) processes.
In this work, the EISI cross-section for the ground state \left\textKr\right4\mathrmd^105\mathrms^24\mathrmf^13 of \mathrmW^13+ ions is calculated in detail by using the level-to-level distorted-wave (LLDW) method, which mainly includes the contributions of direct ionization (DI) and excited auto-ionization (EA) cross-sections to the EISI cross-section.
Our computational results indicate that when configuration interaction is considered, the calculated values show excellent agreement with experimental data for electron impact energies exceeding 500 eV. However, significant discrepancies still exist near the ionization threshold. It is confirmed that these discrepancies primarily originate from the presence of long-lived metastable ions.
To achieve better agreement with experimental observations, we further calculate EISI cross-sections for 71 energy levels of the metastable state \text4d^10\text5s^2\text4f^12\text5p with lifetimes longer than 1.5×10
–5 s. The total EISI cross-sections of these 71 energy levels are obtained through theoretical fitting and compared with the experimental results by Schury et al
. (
2020 J. Phys. B: At. Mol. Opt. Phys. 53 015201). It is found that our results are in good agreement with the experimental results of Schury et al. after considering the contribution of long-lived metastable.