OSCILLATOR-STRENGTHS OF SELECTED RESONANCE TRANSITIONS IN NEUTRAL SULFUR

Mean lives and branching ratios for the 4s S-3(1)o and 4s'' P-3(1.2)o levels of neutral sulfur were determined at the Toledo Heavy Ion Accelerator using beam-foil spectroscopic techniques. The mean lives obtained for the 4s S-3(1)o, 4s'' P-3(1)o, and 4s'' P-3(2)o levels, 1.875 +/- 0.094 ns, 2.034 +/- 0.102 ns, and 2.146 +/- 0.129 ns, respectively, represent the most accurate results available to date. Oscillator strengths for the transitions 3p4 P-3(2, 1, 0)-4s S-3(1)o and 3p4 P-3(2, 1, 0)-4s'' P-3(1, 2)o were derived from these mean lives together with the measured branching ratios. For comparison with published results which present only multiplet f-values, such f-values were computed from the measured individual line oscillator strengths. The value obtained for the 3p4 P-3-4s S-30 multiplet at 1814 angstrom is 0.088 +/- 0.005, in good agreement with the mean of previous experimental measurements and theoretical calculations. With the mean life for the 4s'' P-3(0)o level set equal to the mean of our determination for the other two 4s'' P-3o levels (a valid assumption for LS coupling conditions, and consistent with the observed equality of the mean lives within the accuracy of our measurement), an oscillator strength for the 1299 angstrom multiplet of 0.121 +/- 0.004 was found. Both results are in good agreement with recent large-scale theoretical calculations that incorporate the effects of configuration interaction.