title: Diffusing-Wave Spectroscopy of Dynamics in a Three-Dimensional Granular Flow
abstract: Diffusing-wave spectroscopy was used to measure the microscopic dynamics of grains in the interior of a three-dimensional flow of sand. The correlation functions show that minutely separated grains fly from collision to collision with large random velocities. On a time scale 10(3) to 10(4) times longer than the average time between collisions, the grains displayed slow, collective rearrangements, which, at the long-time limit, produced diffusive dynamics.
authors.affiliation: Department of Physics and Astronomy, University of California, Los Angeles, CA 90095-1547, USA.
authors.initials: N
authors.lastname: Menon
authors.initials: DJ
authors.lastname: Durian