Dirac R--matrix calculations of electron--impact excitation of neon--like krypton

Abstract

We have employed the Dirac R-matrix method to determine electron-impact excitation cross sections and effective collision strengths in Ne-like Kr26+. Both the configuration-interaction expansion of the target and the close-coupling expansion employed in the scattering calculation included 139 levels up through n = 5. Many of the cross sections are found to exhibit very strong resonances, yet the effects of radiation damping on the resonance contributions are relatively small. Using these collisional data along with multi-configuration Dirac Fock radiative rates, we have performed collisional-radiative modeling calculations to determine line-intensity ratios for various radiative transitions that have been employed for diagnostics of other Ne-like ions.