Details

Autor(en) / Beteiligte

• Stark, G
• Herde, H
• Lyons, J R
• Heays, A N
• de Oliveira, N
• Nave, G
• Lewis, B R
• Gibson, S T

Titel

Fourier-transform-spectroscopic photoabsorption cross sections and oscillator strengths for the S 2  BΣu-3-XΣg-3 system

Ist Teil von

• The Journal of chemical physics, 2018-06, Vol.148 (24), p.244302

Ort / Verlag

United States

Erscheinungsjahr

2018

Link zum Volltext

Quelle

American Institute of Physics (AIP) Journals

Beschreibungen/Notizen

• Photoabsorption cross sections and oscillator strengths for the strong, predissociating vibrational bands, v ≥ 11, in the S  BΣu-3-XΣg-3(v,0) system are reported. Absorption measurements were undertaken on S vapor produced by a radio-frequency discharge through H S seeded in helium, and also in a two-temperature sulfur furnace, at temperatures of 370 K and 823 K, respectively. S column densities were determined in each source by combining experimental line strengths in low-v non-predissociating B - X bands (v < 7) with calculated line f-values based on measured radiative lifetimes and calculated branching ratios. The broad-band capabilities of two vacuum-ultraviolet Fourier-transform spectrometers, used with instrumental resolutions of 0.22 cm and 0.12 cm , respectively, allowed for simultaneous recordings of both non-predissociating and predissociating bands, thus placing the predissociating-band cross sections on a common absolute scale. Uncertainties in the final cross section datasets are estimated to be 15% for the 370-K vapor and 10% for the 823-K vapor. The experimental cross sections are used to inform a detailed predissociation model of the B(v) levels in Paper II [Lewis et al., J. Chem. Phys. 148, 244303 (2018)]. For astrophysical and other applications, this model can be adjusted simply to provide isotopologue-specific cross sections for a range of relevant temperatures.