'International Symposium on Molecular Spectroscopy'
Abstract
The collision-induced absorptions (CIA) of O2 and dry air were measured in the near-infrared and visible region, covering the O2 B-band at 687 nm and double transitions in the 630 and 577 nm region. A newly customized 1 m pathlength high-pressure cell was developed and configured to a Fourier transform spectrometer, Bruker 125HR, at the Jet Propulsion Laboratory. A super luminous cutting-edge Laser-Driven Light Source (LDLS), was also used to improve the photon flux offered by the spectrometer. A series of spectra of pure O2 and dry air were obtained at various pressures up to 131 bars at room temperature. For the CIA of O2 B-band region, the monomer resonance absorption contribution to the observed spectra has been subtracted by simulating their absorption with a speed-dependent Voigt line shape profile with line mixing effects taken into account. The remaining absorption component was interpreted as the CIA component in the region. The integrated absorption coefficient was measured to be 0.024(6)×10−4 cm−1/Amag2 for the O2 B-band region, which are significantly lower than early measurements. For the two double transition bands in the 630 and 577 nm regions, however, the integrated CIA from this work were measured to be 2.50(14) and 3.17(18)×10−4 cm−2/Amag2, respectively, which are significantly higher than their corresponding early measurements. For dry air, the integrated CIA were measured to be 0.10(2) and 0.15(2)×10−4 cm−2/Amag2, respectively, for the 630 and 577 nm region, with no appreciable contribution from the O2-N2 pairs in this work. The results are compiled in electronic supplements.&& Government sponsorship acknowledged
