Electron-impact triple ionization of Se 2 +

2021

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We study electron-impact single-ionization cross-sections for all levels of the ground configuration of the Ar 2+ ion using the distorted wave approximation. We investigate the influences of the direct ionization and excitation-autoionization processes on the total singleionization cross sections. We used corrected energies for the levels of the Ar 3+ ion so that the ionization threshold corresponds to the value recommended by National Institute of Standards and Technology (NIST). Radiative damping is taken into account for the ionization cross-sections of the indirect process. Excitations from the 3s and 3p subshells are investigated for the indirect process. We demonstrate that the excitations from the outermost 3p subshell of the ground configuration provide an important contribution to the single ionization cross-sections at low energies. Fairly good agreement with measurements is obtained for the ground level of the Ar 2+ ion. We show that the direct ionization provides ∼70% at peak of the total single-ionization cross-sections.

Section: Resultssupporting

confidence: 73%

“…& Loch 2016;Konceviciūtė et al 2018;Pindzola & Loch 2018;Koncevičiutė et al 2019). This means that the calculated singleionization cross-sections have to be corrected by cross-sections transferred to the direct double ionization(Pakalka et al 2018).…”

mentioning

confidence: 99%

Electron-impact ionization of Ar²⁺

Kynienė

2021

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“…This is slightly below the National Institute of Standards and Technology's (NIST) recommended value of 16.35 eV (Kramida et al 2019). On the other hand, the same tendency for the FAC ionization thresholds compared to the NIST data were also determined for other ions (Jonauskas et al 2015;Konceviciūtė et al 2018;Jonauskas 2018; Kynienė et al 2019b). .…”

Section: Resultssupporting

confidence: 57%

Electron-impact single ionization of Si⁺

2020

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Electron-impact single ionization is studied in the Si+ ion by considering transitions among energy levels. The study includes excitation-autoionization (EA) and collisional ionization processes. The excitations are investigated up to shells with the principal quantum numbers n ≤ 10. It is shown that correlation effects included in the EA calculations play a crucial role in explaining measurements. The correlation effects diminish the EA cross sections by ∼30% compared to single-configuration calculations. However, the collisional ionization is not significantly affected by an extension of the basis of interacting configurations. Good agreement between the presented level-to-level distorted wave data and experimental measurements is found for the single ionization of the Si+ ion.

“…A multi-step approach was previously applied to study DDI in various elements (Jonauskas et al 2014;Koncevičiūtė & Jonauskas 2016;Koncevičiūtė et al 2018). It was Tables 1-12 are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.…”

Section: Introductionmentioning

confidence: 99%

Electron-impact double ionization of the carbon atom

2018

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Electron-impact single- and double-ionization cross sections and Maxwellian rate coefficients are presented for the carbon atom. Scaling factors are introduced for the electron-impact excitation and ionization cross sections obtained in the distorted wave (DW) approximation. It is shown that the scaled DW cross sections provide good agreement with measurements for the single ionization of the C atom and C1+ ion. The direct double-ionization (DDI) process is studied using a multi-step approach. Ionization–ionization, excitation–ionization–ionization, and ionization–excitation–ionization branches are analyzed. It is demonstrated that the three-step processes contribute ≼40% of the total DDI cross sections for the case where one of the electrons takes all of the excess energy after the first ionization process.