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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 A in Cl II and 1011 A 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.

Lifetime measurements are reported for levels arising from the 5s25d and 5s24f configurations in Sn II. Measured decay curves were jointly analyzed using the Arbitrarily Normalized Decay Curve (ANDC) method to remove the effects of cascade repopulation from the determination of the lifetimes of the 5s25d 2D3/2 level. The branching ratio of the decay of this level to the ground term fine-structure levels 2P1/2 and 2P3/2 was carefully measured, and we have obtained an accurate value for the absorption oscillator strength of the resonance transition to this level at 1400.52 A. The results are discussed in the context of interpreting vacuum ultraviolet absorption spectra observed with the Goddard High Resolution Spectrograph on board the Hubble Space Telescope.