Near‐infrared absorption cross sections and integrated absorption intensities of molecular oxygen (O₂, O₂‐O₂, and O₂‐N₂)

Abstract

Near‐infrared absorption cross sections and integrated absorption intensities of gas phase oxygen and nitrogen mixtures have been determined from laboratory measurements using a coolable multipass gas cell and Fourier transform spectroscopy. Spectra were recorded at instrument resolutions of 0.5 and 0.05 cm −1 , between 2200–12,500 cm −1 (between 4.5 and 0.8 μm). Monomer and binary cross sections of the a 1 Δ g ← χ 3 Σ g − (0,0) and (1,0) bands and underlying continuum absorptions of oxygen centered near 7,850 and 9,400 cm −1 (1.27 and 1.06 μm) were determined for mixtures of 21%, 50%, and 75% oxygen in nitrogen, from measurements at a total pressure of 100 kPa (1000 mbar) and temperatures of 200, 230, and 294 K. Where possible, comparisons are made between the results obtained from this work and those of previous studies.