Electron impact excitation rates for transitions in carbon-like F IV, Na VI, AI VIII, P X, S XI, CI XII, Ar XIII and K XIV

Abstract

Electron excitation rates for all fine-structure transitions among the 1s22s22p2 and the 1s22s2p3 configurations of C-like F IV, Na VI, Al VIII, P X, S XI, Cl XII, Ar XIII and K XIV are determined by interpolating similar data for O III, Ne V, Mg VII, Si IX and Ca XV, that were calculated using the R-matrix method. Results are presented as polynomial fits in log Te to the effective collision strengths (Υ) for each transition. The fits may be used to estimate values of Υ accurate to approximately ±20% over a temperature range of log Tmax ± 0.8 dex, where Tmax is the temperature of maximum fractional abundance in ionization equilibrium of the relevant species. A comparison of the present results for Ar XIII with the earlier distorted wave calculations of Bhatia et al. reveals significant differences.