|Electron-excitation of the fine-structure transition|
|in chlorine-like ions Ar II to Ni XII|
|Astronomy & Astrophysics Supplement Series, 1995, Vol.110, No.1, pp.209-212|
Calculated effective collision strengths for the ground term fine-structure transitions of 11 chlorine-like ions (17 electrons) from Ar II to Ni XII are presented. There is currently very little published data for this sequence and so there is a strong motivation to satisfy the need for this information and to improve upon the accuracy of previous work where it does exist. The data are calculated using R-matrix techniques and are provided over a temperature range from 10(3) K up to 10(7) K over which the target models should be valid. Accuracy for the effective collision strengths is in the region of 10%. An independent calculation on Fe X recently published by Mohan et al. (ApJ 434, 389) is shown to be wrong for this transition because of their omission of important low-energy contributions.