  In this work, we report on microgravity studies of particle ensembles
simulating ice-particle collisions in Saturn's dense main rings. We have
developed an experimental method to study the energy dissipation in a many-body
system consisting of approx. one hundred cm-sized glass spheres. The temporal
development of the mean particle velocity, ranging from ~10 cm/s (at the
beginning) to ~0.35 cm/s (after 9s of experiment duration), can be explained by
a constant coefficient of restitution of 0.64. A comparison to values obtained
for pure water-ice bodies shows that future cryogenic ice-collision experiments
can achieve collision velocities of ~0.1 cm/s, and thus will very well simulate
the conditions in Saturn's main rings.
