Effective collision strengths for transitions in Fe XV

Abstract

Collision strengths for transitions among the energetically lowest 53 fine-structure levels belonging to the (1s22s22p6) 3ℓ2, 3ℓ3ℓ′, 3s4ℓ and 3p4s configurations of Fe XV are computed, over an electron energy range below 160 Ryd, using the Dirac Atomic R-matrix Code (DARC) of Norrington & Grant (2003). Effective collision strengths, obtained after integrating the collision strengths over a Maxwellian distribution of electron energies, have also been calculated. These results of effective collision strengths are tabulated for all 1378 inelastic transitions over a wide temperature range of 105 to 107 K. Comparisons are also made with other R-matrix calculations and the accuracy of the results is assessed.