Spectral analysis of the light scattered from a chemically relaxing fluid: a ternary mixture

Abstract

The spectral distribution of light scattered by a ternary fluid mixture containing two chemically reactive species and one nonreactive species is considered and a normal mode analysis is carried out for a range of k-values for which the pressure fluctuations are decoupled from those in entropy and concentration. The expressions obtained for both the lorentzian and non-lorentzian contributions to the Brillouin lines are straightforward extensions of those obtained for the binary reactive mixture. The damping and strength factors of the three lorentzian contributions to the Rayleigh line are rather complicated functions of the transport coefficients and chemical relaxation time. As illustrative examples the situations where (a) the nonreactive species or (b) the two reactive species are present in very low concentration are considered in some detail.