The Spectrum of Neutral Sulfur (S I) in the Vacuum Ultra-Violet

Observations and measurements were made of 114 lines of SI between 1157 Å and 2169 Å in the first, second and third orders of the NBS 10.7-m normal incidence vacuum spectrograph. All of these lines involve transitions to levels of the 3 s 2 3 p 4 ground configuration. Two lines at 4152 and 4157 Å were also measured. Wavelength uncertainties range from less than ± 1 mÅ up to ± 3 mÅ. Energy levels and their uncertainties derived from these data are given. The ionization energy is 83 559.3 ± 0.3 cm -1 .