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

Abstract

We present results for the outer-shell electron-impact excitation of all Na-like ions from Mg+ to Kr25+ obtained using the intermediate-coupling frame transformation R-matrix approach. For each ion's calculation, the target and close-coupling expansions are both taken to be the 18 LS terms (32 levels) belonging to configurations [1s(2)2s(2)2p(6)]3l, 4l, 5l and 6l (l = 0-5). Effective collision strengths ((sic)s) are presented at temperatures ranging from 2 x 10(2)(q + 1)(2) K to 2 x 10(6)(q + 1)(2) K (where q is the residual charge of ions, i.e. Z - 11). Detailed comparisons for the (sic)s are made with the results of previous calculations for several ions, which span the sequence. Furthermore, we examine the iso-electronic trends of both low- and high-temperature effective collision strengths