OPTICAL OSCILLATOR-STRENGTHS OF NOBLE-GAS RESONANCE TRANSITIONS IN THE VACUUM-ULTRAVIOLET REGION

We report the results of an accurate measurement of the optical oscill ator strengths of the prominent resonance lines of He, Ne, Ar, and Kr in the vacuum-ultraviolet region based on the absorption of resonance radiation. The transmission of this radiation through a layer of gas o f finite thickness is measured as a function of the number density of the gas. The transmission function is fitted to this data to obtain th e absorption oscillator strength. The accuracy of the present measurem ents ranges from 2.5% to 4%. The results are as follows: HeI (58.4 nm) , 0.2683 +/- 0.0075 (2.8%); HeI (5.37 nm), 0.0717 +/- 0.0024 (3.4%); N eI (74.4 nm), 0.010 17 +/- 0.000 30 (2.9%); NeI (73.6 nm), 0.1369 +/- 0.0035 (2.6%); ArI (106.7 nm), 0.0616 +/- 0.0021(3.4%); ArI (104.8 nm) , 0.2297 +/- 0.0093(4.0%); KrI (123.6 nm), 0.1751 +/- 0.0049 (2.8%); K rI (116.5 nm), 0.1496 +/- 0.0038(2.5%).