Simulation of collisions in planetary rings

We investigate the evolution of structures in planetary rings in the neighbourhood of the orbit of an embedded moonlet (small satellite). The effects of collisions have been taken into account by introducing the velocity dependent restitution coefficient according to experimental and theoretical results. Here we present results of recent many-particle simulations which show a significant influence of the interparticle collisions on the formation and persistence of wake structures in a model ring. In contrary to the collision-free model, a stationary, non-mirrorsymmetric wake pattern with decreasing intensity in azimuthal direction is observed. The azimuthal damping rate of the wake intensity is estimated from the data obtained in the simulation.