a Measurement of the Optical Oscillator Strengths of Noble Gas Resonance Transitions in the Vacuum Ultraviolet

We report the results of an accurate measurement of optical oscillator strengths of the prominent resonance lines of He, Ne, Ar and Kr in the vacuum ultraviolet. To measure the oscillator strength of a resonance line we make use of the absorption of the resonance radiation as it passes through the gas to a detector. The transmission of this radiation through a layer of gas of finite thickness is measured as a function of the number density of the gas. The transmission function is fitted to this data to obtain the absorption oscillator strength. The accuracy of the present measurements ranges from 2.5% to 4% and is reflected in the uncertainties presented below. The results are for He I (58.4 nm) 0.2683 +/- 0.0075 (2.8%), He I (53.7 nm) 0.0717 +/- 0.0024 (3.4%), Ne I (74.4 nm) 0.01017 +/- 0.00030 (2.9%), Ne I (73.6 nm) 0.1369 +/- 0.0035 (2.6%), Ar I (106.7 nm) 0.0616 +/- 0.0021 (3.4%), Ar I (104.8 nm) 0.2297 +/- 0.0093 (4.0%), Kr I (123.6 nm) 0.1751 +/- 0.0049 (2.8%) and Kr I (116.5 nm) 0.1496 +/- 0.0038 (2.5%).