Transition Probabilities and Electron Excitation Rates for Fexiv

Abstract

Electron impact excitation rates and oscillator strengths for transitions between fine-structure levels of the 3s23p, 3s3p2, and 3s23d configurations and from these levels to the fine-structure levels of the 3p3, 3s3p3d, and 3p23d configurations in Fe XIV are reported. The 135 target levels have been included in the close-coupling expansion in our collision calculation using the Breit-Pauli R-matrix approach. The lowest 135 Fe XIV energy levels belong to the 3s23p, 3s3p2, 3s23d, 3p3, 3s3p3d, 3p23d, 3s3d2, 3p3d2, 3s24s, 3s24p, 3s3p4s, and 3s24d configurations. An accurate representation of target levels has been obtained using spectroscopic and correlation radial functions. The atomic wave functions give excitation energies which are in close agreement with experiment. Oscillator strengths and transition probabilities for Fe XIV lines normally compare very well with previous calculations. The effective collision strengths have been calculated by integrating total resonant and nonresonant collision strengths over a Maxwellian distribution of electron energies and these are presented over a wide temperature range suitable for modeling of astrophysical plasmas. Significant differences in collision strengths are noted with the previous 18 state R-matrix calculation.