Single-electron capture in keV Ar^15+…18++He collisions

Abstract

Single-electron capture in 14 keV q−1 Ar15+…18++He collisions is investigated both experimentally and theoretically. Partial cross sections and projectile scattering angle dependencies have been deduced from the target ion recoil momenta measured by the COLTRIMS technique. The comparison with close-coupling results obtained from a two-centre extension of the basis generator method yields good overall agreement, demonstrating the applicability of close-coupling calculations to collision systems involving highly charged ions in charge states up to 18+.

Kinematically complete study of electron transfer and rearrangement processes in slowAr16+-Ne collisions

“…tfischer@mpi-hd.mpg.de and yields very good overall agreement with the experimental partial as well as DCSs [7]. So far, BGM calculations for highly charged projectile ions up to q = 20 are available.…”

“…[13]. Although we have not made such a comparison here, Knoop et al [7] showed that a TC-BGM calculation can give a good agreement with the experimental state-selective angular distribution.…”

“…After being accelerated over a distance of 11 cm, the recoil ions passed a field-free region of 22 cm and were detected by a position-sensitive detector (PSD). In contrast to our previous experiments [6,7] with this setup, the recoil-ion PSD has been changed to a larger diameter (0 80 mm) and there is a bore (0 6 mm) in its center [23]. The PSD was placed in the center of the beam line, and its central bore allows the primary beam to enter the reaction microscope.…”

“…The captured electrons populate primarily only two or three excited pro jectile n shells (see, e.g., Refs. [6,7]), i.e., the process is highly state selective. Many aspects of this are well described by a multichannel Landau-Zener model (MCLZ) [2,8] or a classical over-barrier model (OBM) [3,9,10].…”

Transfer excitation reactions in fast proton-helium collisions

“…Especially at higher impact energies E p > 100 keV/u, where the final electronic state determination in experiments is challenging or often impossible, the influence of excitation has not been investigated [20][21][22][23]. Projectile scattering angle distributions, which are final state selective, are rather rare [1,24,[26][27][28][29][30][31][32]. All these measurements were only possible due to the development of a modern momentum imaging technique, cold target recoil ion momentum spectroscopy (COLTRIMS) combined with optimized threedimensional focusing ion optics, which achieves longitudinal momentum resolution <0.04 a.u.…”