R-matrix electron-impact excitation data for the Ne-like iso-electronic sequence

G. Y. Liang, N. R. Badnell

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Abstract

We present results for the electron-impact excitation of all Ne-like ions from Na+ to Kr26+ obtained using the intermediate-coupling frame transformation R-matrix approach. For each ion's calculation, the close-coupling expansion is taken to be the 113 LS terms (209 levels) belonging to the configurations [1s(2)]2s(2)2p(6), 2s(2)2p(5){3, 4, 5}l, 2s2p(6){3, 4, 5}l (l is an element of s, p, d, f, and g), and 2s(2)2p(5){6, 7} l' (l' is an element of s, p, and d). An additional configuration interaction effect arising from configurations of 2s(2)2p(4)3l{3, 4, 5}l" (l" is an element of s, p, d, f and g) was included in the target expansion. A detailed comparison of the target structure has been made for six specific ions (Si4+, Ar8+, Ca10+, Fe16+, Ni18+, and Kr26+) spanning the sequence to assess the accuracy for the entire sequence. Effective collision strengths (Gamma s) are presented at temperatures ranging from 2x10(2)(q+1)(2) K to 2x10(6)(q+1)(2) K (where q is the residual charge of ions, i. e. Z-10). Detailed comparisons for the.s are made with the results of previous calculations for several ions, which span the sequence. Furthermore, we examine the iso-electronic trends of effective collision strengths as a function of temperature. The present results are the only R-matrix ones for the majority of the ions and the most extensive and complete data for modelling to-date.

Original languageEnglish
Number of pages20
JournalAstronomy and Astrophysics
Volume518
Issue numberJuly/August
DOIs
Publication statusPublished - 3 Sep 2010

Keywords

  • atomic data
  • atomic processes
  • plasmas
  • collision strengths
  • FE-XVII
  • energy-levels
  • breit-pauli
  • NI-XIX
  • laboratory measurements
  • rate coefficients
  • radiative rates
  • emission-lines

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