Theoretical study of single‐electron capture in the N⁵⁺ + He and O⁶⁺ + He collisions by means of ab initio methods

Abstract

Partial cross sections of single-electron capture on the n = 3 levels have been determined theoretically for the NSf + He and 06+ + He collisions by means of a semiclassical method using ab initio potential energy curves and radial and rotational coupling matrix elements. The different behavior of these two isoelectronic systems is fairly well reproduced by our calculations.

Polarization degree differences for the3p 2P3/2–3s 2Liu1, Zhao2, Wang3 et al. 2010Phys. Rev. A6270View full textAdd to dashboardCite

“…We note that the MOCC results of Ref. [22] are also outside the experimental error bars for most of the energies, which demonstrates the difficulties in the calculations of state-selective electron cross sections in many-electron systems. It is noteworthy that in the N 5+ -He collision system, the dominant channel in the low-energy region is the capture to the 3s state, while for the N 5+ -H 2 reaction, it is the capture to the 3p and 3d states.…”

“…1(b)] collision systems, respectively, which are the predominantly populated capture states in the considered energy range. The corresponding experimental data [20,21] and the MOCC results [22] are also given in this figure for comparison. All the results are mutually consistent regarding the energy behavior of the cross section but there exist discrepancies regarding its magnitude.…”

Measurement and calculation of absolute single- and double-charge-exchange cross sections forO6+ions at 1.17 and 2.33 keV/u impacting He andH2

“…In addition to results of the present CTMC theoretical approach, state-selective cross sections have been calculated by extension of atomic-orbital expansion with close coupling to a two-electron system [50], in a combined ab initio approach (for the potential energy curves and couplings) with a semiclassical collision calculation [51], the traveling molecular-orbital method [52], a semiclassical molecular-orbital approximation [53], and the two-center atomic-orbital close-coupling method [54]. Spectroscopic measurements of state-selective cross section for charge transfer have been carried out for several ions, including O 6+ colliding with He and H 2 in an energy range containing the present impact energies [38].…”

Theoretical treatment of electron capture processes for closed‐ and open‐ shell systems

“…The method was first applied to closed-shell collisional systems such as the two isoelectronic ions 06+/He [15,16] and N5+/He [14] and the test case He2+/He [17] and has shown good agreement with experiment for the partial cross sections on the nl sublevels of single-electron capture [15] as well as for double-electron capture processes [17]. The method is now extended to open-shell multicharged ion collisional systems [18], which are of major importance and cannot be studied otherwise.…”

“…Recently, we have developed a full ab initio molecular treatment of electron capture processes in the keV energy range using ab initio configuration interaction calculations for the determination of the potential energy curves and of the radial and rotational coupling matrix elements followed by a semiclassical collisional treatment. The method was first applied to closed-shell collisional systems such as the two isoelectronic ions 06+/He [15,16] and N5+/He [14] and the test case He2+/He [17] and has shown good agreement with experiment for the partial cross sections on the nl sublevels of single-electron capture [15] as well as for double-electron capture processes [17]. The method is now extended to open-shell multicharged ion collisional systems [18], which are of major importance and cannot be studied otherwise.…”