QUASI-ELASTIC SCATTERING OF SYNCHROTRON-RADIATION BY TIME-DOMAIN INTERFEROMETRY

We use synchrotron radiation and time resolved x-ray detection to meas ure structural relaxations of glycerol [C3H5(OH)(3)] having time scale s of 30 to 200 ns at 1.5 Angstrom(-1) momentum transfer. Foils contain ing Fe-57 (14.4 keV nuclear resonance, 141 ns lifetime) are placed bef ore and after the nonresonant sample, and a small difference (similar to 70 MHz) is established in their nuclear response frequencies. Quasi elastic scattering from the sample perturbs the 70 MHz quantum beat pa ttern of the nuclear scattering. A simple model relates the perturbati on to the dynamic structure factor of the sample.