Lineshifts in the Fundamental Band of CO: Confirmation of Experimental Results for N2 and Comparison with Theory

Line Broadening and Shifting Studies of the J=5←4 Transition of Carbon Monoxide Perturbed by CO, N2, and O2

“…The observed consistency of linewidth data for pure rotational and rovibrational transitions allows the conclusion that line broadening of the rovibrational line is predominantly governed by rotational relaxation phenomena involving rates due to collision-induced transitions between rotational levels which are not much dependent on the vibrational state. In contrast to this behavior, the lineshift data for the observed pure rotational transition (see Table 1) differ significantly from the corresponding values for the R-branch m = 5 transition of the fundamental vibrational band, determined to −82(10) kHz/Torr for CO-CO (17), −72.8 kHz/ Torr for CO-N 2 (32), and −84.9 kHz/Torr for CO-O 2 (33), respectively. Such differences are related to the fact that the rovibrational lines are predominantly shifted due to the isotropic part of the shifting cross section which does not contribute to the shifts of pure rotational transitions (36).…”

Shifting and broadening in the fundamental band of CO highly diluted in He and Ar: A comparison with theory

“…The temperature of the sample cell was 296Ϯ1 K. Two sets of measurements were made, one with CO highly diluted in He and the other with CO highly diluted in Ar. For further experimental details and an example of simultaneously recorded spectra, the reader is referred to Luo et al 7 As in Ref. 7, the center of the reference line was determined by fitting it to a Lorentzian profile.…”

Line Broadening and the Temperature Exponent of the Fundamental Band in CO–N2 Mixtures

“…We had measurements at 301 K and 53.3 kPa (28), 299.9 K and 68.05 kPa (46), and new measurements at 296.5 K and 48.55 kPa in a 4-m-long cell. We explained earlier how these were brought to a common temperature.…”