Resonance-enhanced electron-impact excitation of Cu-like goldShow others and affiliations
2017 (English)In: Journal of Quantitative Spectroscopy and Radiative Transfer, ISSN 0022-4073, E-ISSN 1879-1352, Vol. 198, p. 48-58Article in journal (Refereed)
Abstract [en]
Employing the independent-process and isolated-resonance approximations using distorted-waves (IPIRDW), we have performed a series of calculations of the resonance-enhanced electron-impact excitations (EIE) among 27 singly excited levels from the n <= 6 configurations of Cu-like gold (Au, Z = 79). Resonance excitation (RE) contributions from both the n = 4 -> 4 - 7 and n = 3 -> 4 core excitations have been considered. Our results demonstrate that RE contributions are significant and enhance the effective collision strengths (Upsilon) of certain excitations by up to an order of magnitude at low temperature (10(6.1) K), and are still important at relatively high temperature (10(7.5) K). Results from test calculations of the resonance-enhanced EIE processes among 16 levels from the n <= 5 configurations using both the Dirac R-matrix (DRM) and IPIRDW approaches agree very well with each other. This means that the close coupling effects are not important for this ion, and thus warrants the reliability of present resonance enhanced EIE data among the 27 levels. The results from the collisional-radiative model (CRM) show that, at 3000 eV, near where Cu-like Au is most abundant, RE contributions have important effects (up to 25%) on the density diagnostic line intensity ratios, which are sensitive near 10(20) cm(-3). The present work is the first EIE research including RE contributions for Cu-like Au. Our EIE data are more accurate than previous results due to our consideration of RE contributions, and the data should be helpful for modeling and diagnosing a variety of plasmas. (C) 2017 Elsevier Ltd. All rights reserved.
Place, publisher, year, edition, pages
Pergamon Press, 2017. Vol. 198, p. 48-58
Keywords [en]
Electron-impact excitation, Resonance excitation, Collision strength, Distorted-wave, Collisional-radiative model
National Category
Natural Sciences
Identifiers
URN: urn:nbn:se:mau:diva-2474DOI: 10.1016/j.jqsrt.2017.05.001ISI: 000404306100005Scopus ID: 2-s2.0-85019152458Local ID: 23653OAI: oai:DiVA.org:mau-2474DiVA, id: diva2:1399227
2020-02-272020-02-272024-06-17Bibliographically approved