Rare gas pressure broadening of the NO fundamental vibrational band

Pressure broadening of rotational transitions in the nitric oxide fundamental band was studied using Fourier transform spectroscopy, Rotational level dependent broadening coefficients were determined for both the (2)Pi (1/2) and (2)Pi (3/2) substates at 300 K using the five noble gases as the broadening species. Pressure broadening coefficients were also determined for Q-branch transitions using At as the collision partner. This information was subsequently used to study the broadening of the Q-branch absorption lines at 900 Torr total pressure. The high-pressure spectra showed significant deviations from a simple fit using a sum of Lorentzians that indicated the possible effects of line coupling. (C) 2001 Academic Press.