Excitation and charge transfer in low-energy hydrogen-atom collisions with neutral atoms: Theory, comparisons, and application to Ca
2016 (English)In: PHYSICAL REVIEW A, ISSN 2469-9926, Vol. 93, no 4, 042705Article in journal (Refereed) PublishedText
A theoretical method is presented for the estimation of cross sections and rates for excitation and charge-transfer processes in low-energy hydrogen-atom collisions with neutral atoms, based on an asymptotic two-electron model of ionic-covalent interactions in the neutral atom-hydrogen-atom system. The calculation of potentials and nonadiabatic radial couplings using the method is demonstrated. The potentials are used together with the multichannel Landau-Zener model to calculate cross sections and rate coefficients. The main feature of the method is that it employs asymptotically exact atomic wave functions, which can be determined from known atomic parameters. The method is applied to Li + H, Na + H, and Mg + H collisions, and the results compare well with existing detailed full-quantum calculations. The method is applied to the astrophysically important problem of Ca + H collisions, and rate coefficients are calculated for temperatures in the range 1000-20 000 K.
Place, publisher, year, edition, pages
2016. Vol. 93, no 4, 042705
Astronomy, Astrophysics and Cosmology
IdentifiersURN: urn:nbn:se:uu:diva-297904DOI: 10.1103/PhysRevA.93.042705ISI: 000374523500005OAI: oai:DiVA.org:uu-297904DiVA: diva2:944345
FunderThe Royal Swedish Academy of SciencesWenner-Gren FoundationsGöran Gustafsson Foundation for promotion of scientific research at Uppala University and Royal Institute of TechnologySwedish Research CouncilKnut and Alice Wallenberg Foundation