Experimental Polarizability Transition Moments of CO₂ for Excited Vibrational States

The Raman spectrum of CO₂ from room temperature to 1800 K has been measured in a series of experiments. The differential Raman scattering cross-sections for the fundamental bands at 1285.41 cm^-1 and 1388.18 cm^-1 have been obtained from reference bands of H₂ and N₂ as intensity standards. The Raman cross-sections of CO₂ hot bands, involving vibrational energy levels up to 5000 cm^-1, were derived from those of the fundamental bands. The Raman cross-sections obtained this way were reduced to transition moments of the mean molecular polarizability, which make it possible to simulate the Raman spectrum of CO₂ up to 2000 K. This paves the way for local or remote diagnostics of CO₂ in hot environments using Raman based techniques.