Collisional line broadening and mixing in the Raman spectrum of CO perturbed by N2: Experimental measurements and theoretical calculations

D. Paredes-Roibás (1, 2) , R.Z. Martínez (2) , H. Jóźwiak (3) , Franck Thibault (4)

1 UNED - Universidad Nacional de Educación a Distancia
2 IEM - Instituto de Estructura de la Materia
3 Nicolaus Copernicus University [Toruń]
4 IPR - Institut de Physique de Rennes

We present a joint experimental and theoretical study of line broadening and mixing in the Q branch of the Raman spectrum of CO perturbed by N2 at 77, 195 and 298 K. Advanced methods and facilities have been used for both aspects of the study: the experiments were conducted using a high-resolution stimulated Raman spectroscopy setup, while the calculations were performed using a quantum dynamical formalism and one of the most recent potential energy surfaces available. Line broadening coefficients were determined experimentally for rovibrational lines up to j=11 at 77 K, j=15 at 195 K and j=19 at 298 K, and calculated for lines up to j=6 at the three temperatures. Line mixing was also observed and coefficients measured for lines up to j=8 at 77 K and j=5 at 195 K, and again calculated up to j=6 at the three temperatures. A comparison shows an overall very good agreement between experiments and calculations for both sets of coefficients. Additional calculated data for the pure rotational R and S lines are also provided.

Mots clés: Quantum dynamical calculations; Line mixing; Collisional broadening; CO-N2; Stimulated Raman spectroscopy; Molecular physics; Quantum dynamics; Atomic and molecular collisions

Domaines: Physique [physics]

D. Paredes-Roibás, R.Z. Martínez, H. Jóźwiak, Franck Thibault. Collisional line broadening and mixing in the Raman spectrum of CO perturbed by N2: Experimental measurements and theoretical calculations. Journal of Quantitative Spectroscopy and Radiative Transfer, 2021, 275, pp.107868. ⟨10.1016/j.jqsrt.2021.107868⟩. ⟨hal-03334306⟩