Oscillator strengths for ultraviolet transitions in Cl II and Cl III

Oscillator strengths for transitions in Cl II and III are derived from lifetimes and branching fractions measured with beam-foil techniques. The focus is on the multiplets at 1071 Å in Cl II and 1011 Å in Cl III whose lines are seen in spectra acquired with the Far Ultraviolet Spectroscopic Explorer. These data represent the first complete set of experimental f-values for the lines in the multiplets. Our results for Cl II λ1071 agree very well with the most recent theoretical effort and with Morton's newest recommendations. For Cl III, however, our f-values are significantly larger than those given by Morton; instead, they are more consistent with recent large-scale theoretical calculations. Extensive tests provide confirmation that LS coupling rules apply to the transitions for these multiplets.