TEMPERATURES FROM ROTATIONAL-VIBRATIONAL RAMAN Q-BRANCHES

An iterative, least-squares analysis scheme, based on the differential of the intensity, dI = dτ∂I/∂τ + dρ{variant} ∂I/∂ρ{variant} has been developed for obtaining the temperature θ = 1/τ and density ρ{variant} from a set of rotational-vibrational Raman, Q-branch intensities. Spectral locations that cover the maximum variation in ∂I/∂τ were determined from a set of computed intensities and derivatives. The results for the Stokes (anti-Stokes) bands indicate for temperatures less than 2100K (2700K) that the maximum extent of ∂I/∂τ can be spanned by recording intensities only in the first two vibrational bands, v(1-0) and v(2-1) and, due to the multivalued nature of ∂I/∂τ, equally spaced values for ∂I/∂τ can be obtained only by programming the spectrometer to select an appropriate set of non-uniformly spaced passbands. © 1979.