The absorption bands of 12C16O2 near 718 nm

The absorption spectra of carbon dioxide were recorded in the region from 13,500 to 14,200 cm(-1), using a Bruker IFS 125 HR Fourier transform spectrometer and a 30 m multipass cell with the White type optical system. The recording was performed at spectral resolution of 0.03-0.04 cm(-1), room temperature, path length of 1057.95 m and at three pressures of 252, 403 and 582 mbar. The achieved sensitivity (noise equivalent absorption) at the level of k(nu) = 6 x 10(-10) cm(-1) allowed detection of a number of lines of three 2005 i - 00001 ( i = 1,2,3) bands of (CO2)-C-12-O-16 with the intensity values down to 10(-29) cm(-1)/(molecule cm-2) at 296 K. The 20053-00001 band was observed for the first time. The line intensities for all bands were measured for the first time. The uncertainty of the line position measurements was estimated to be about 0.007 cm(-1) for the unblended lines with a high value of the signal-to-noise ratio. The uncertainties of the retrieved line intensities for the strongest unblended lines are on the level of 10%. The spectroscopic constants for the three observed bands were fitted to the observed line positions. The vibrational transition dipole moments squared of these bands were fitted to the observed line intensities. A comparison of the measured line positions to those from the HITRAN2020 database was done. Finally a comparison of the measured line intensities to those contained in the HITRAN2020 database as well as in the new version of the Ames line list was also given. (c) 2023 Elsevier Ltd. All rights reserved.

Automated summary

The absorption spectra of carbon dioxide in a specific region were recorded using a Fourier transform spectrometer and a multipass cell. The sensitivity allowed for detection of multiple lines with varying intensities. Line positions, intensities, and spectroscopic constants were analyzed and compared to existing databases.