FTS measurements of O2 collision-induced absorption in the 565–700 nm region using a high pressure gas absorption cell. (September 2019)

• Record Type: Journal Article
• Authors: Sung, Keeyoon; Wishnow, Edward H.; Crawford, Timothy J.; Nemchick, Deacon; Drouin, Brian J.; Toon, Geoffrey C.; Yu, Shanshan; Payne, Vivienne H.; Jiang, Jonathan H.
• Is Part Of: Journal of quantitative spectroscopy & radiative transfer. Volume 235(2019)
• Page Start: 232
• Page End: 243
• Publication Date: 2019-09
• Subjects: Spectrum analysis -- Periodicals; Radiation -- Periodicals; Analyse spectrale -- Périodiques; Rayonnement -- Périodiques; Radiation; Spectrum analysis; Periodicals; 543.0858
• DOI: 10.1016/j.jqsrt.2019.06.016
• Languages: English
• ISSNs: 0022-4073

Abstract

Highlights: Obtained spectra of O2 and air in the 562–800 nm region at room temperature. Computed Rosenkranz line mixing parameters for O2 (B) band. Adopted speed-dependent Voigt profile for O2 (B) resonance line absorption contribution in presence of line mixing. Measured O2 collision-induced absorption (CIA) in the 687, 630, 577 nm regions. Abstract: The collision-induced absorption (CIA) spectra of oxygen and dry air have been measured in the near-infrared and visible regions, covering the O2 (B) band at 687 nm and double transitions in the 630 nm and 577 nm regions. A custom-design 1 m path length high-pressure cell was developed and configured to a Bruker 125HR Fourier transform spectrometer at the Jet Propulsion Laboratory. A super-luminous Laser Driven Light Source (LDLS) was also used to improve the photon flux incident upon the spectrometer. A series of spectra of pure O2 and dry air were obtained at various high pressures up to 131 bars at room temperature. For the measurement of O2 –O2 CIA in the B band region, the monomer resonance absorption contribution has been subtracted from the observed spectra by simulating the O2 (B) band absorption with a speed-dependent Voigt line shape profile with line mixing effects taken into account. The remaining absorption component was regarded as the CIA in the region. The integrated absorption coefficient was measured to be 3.2(6) × 10 −6 cm −2 /Amagat 2 for the O2 (B) band region, which is significantly lower than literature values. For the two double transition bands in the 630 and 577 nm regions, the integrated CIA bands from the present work were measured to be 2.50(14) and 3.26(18) × 10 −4 cm −2 /Amagat 2, respectively. The present measurements are significantly higher than prior measurements for the 630 nm band region, while they are slightly lower than prior measurements for the 577 nm band region. For dry air, the integrated CIA bands were measured to be 0.10(2) and 0.15(2) × 10 −4 cm −2 /Amagat 2, respectively, for the 630 and 577 nm regions, no appreciable contribution from O2 –N2 pairs was observed. The results are compiled in electronic supplements.