QUASI-ELASTIC GAMMA-RAY SCATTERING FROM GLYCEROL

The Mossbauer scattering instrument at the Missouri University Researc h Reactor (MURR) has been used to study the liquid dynamics of glycero l as a function of temperature. The measurements were made by observin g the Mossbauer gamma rays from the 46.5-keV level in W-183 scattered in the direction corresponding to the first liquid structure peak at Q = 1.36 Angstrom(-1). The widths of the Mossbauer velocity spectra wer e found to be quasielastically broadened by 3.1 mu eV at 24 degrees C up to 55 mu eV at 113 degrees C. The broadening varied quadratically w ith temperature above the melting point, but showed a linear dependenc e when plotted versus the absolute temperature divided by the viscosit y. As discussed by Singh and Mullen, this latter dependence is expecte d in the continuous diffusion limit. The original analysis by Singwi a nd Sojlander was carried out for a diffusing Mossbauer ion, where the observed cross section is the Fourier transform of the self-correlatio n function. Our case requires the use of the pair-correlation function . Quantitative calculations as well as further experiments are needed.