Investigation of the Collision-Induced Absorbtion by O2 Near 6.4 Micro ńin Pure O2 and O2/N2 Mixtures

Published

September 1, 2000

Author(s)

B Mate, C Lugez, A M. Solodov, Gerald T. Fraser, Walter J. Lafferty

Abstract

The collision-induced fundamental vibrational band of molecular oxygen has been measured between 1300 and 2000 cm^-1 using a Fourier-transform infrared spectrometer and an optical path length of 84 m. Spectra were recorded for pure O₂ and O₂/N₂ mixtures at densities up to 10 times the density of an ideal gas at standard temperature (273.15 K) and pressure (101.325 kPa), and for temperatures between 228 and 296 K. The band is dominated by the δJ = 0, Q-branch and the δJ = 2, S and δJ = -2, O-branch shoulders, with the S branch exhibiting ripples previously attributed to bound dimer transitions, pure quadrupole transitions of O₂ perturbed by line mixing, and intercollisional interferences. The ripples are seen at the same wavenumbers in O₂-Ar mixtures, with intensities dependent on both the O₂ and Ar densities, suggesting that the ripples are not due to bound dimer transitions. The integrated band intensity, S, is related to the collision-induced absorption coefficients by S = S_O2-O2P²O₂ + SO₂-N₂ PO₂ PN₂, where S_O2-O2 and O₂-N₂ collisions, respectively, and PO₂ and PN₂ gas densities. We find values for S_O2-O2 = 6,972(66) x 10^-4cm and S_od2^-N₂ = 7.12(22) X 10^-4 cm^-2, respectively, at 296 K, when the gas density is equal to that found at STP (i.e., S_O2-O2 = 6.972(66) x 10^-4 cm^-2 and S_O2-N2 = 7.12(22) x 10^-4 cm^-2, respectively, at 296 K, when the gas density is equal to that found at STP (I.e., S_O2-O2 = 6972(6) x 10^-4 cm⁰² amagat^-2 and S_O2-N2 = 7.12(22) x 10^-4 cm^-2 amagat^-2).

Citation

Journal of Geophysical Research

Volume

105

Issue

No. D17

Pub Type

Journals

Keywords

atmospheric absorption, continuum absorption, electronic spectroscopy, FTIR oxygen

Citation

Mate, B. , Lugez, C. , Solodov, A. , Fraser, G. and Lafferty, W. (2000), Investigation of the Collision-Induced Absorbtion by O₂ Near 6.4 Micro ńin Pure O₂ and O₂/N₂ Mixtures, Journal of Geophysical Research (Accessed April 19, 2024)