Collisional evolution of many - particle systems in astrophysics

Low-velocity collisions play a fundamental role in various astrophysical environments like protoplanetary disks (planet formation) or the Saturnian rings (e.g. dynamics and stability). These collisions are likely to occur at velocities in the cm s−1 range and below, and a satisfactory experimental realization of the lowest velocities is so far not possible even in microgravity environments like a parabolic flight aircraft or a drop tower facility. Moreover, many-particle effects can play an important role, e.g. for clustering (Miller and Luding [1]), which are ignored when only performing single particle-particle collisions. A perfect environment to perform the desired many-particle collision experiments is under microgravity condition with a microgravity time of few minutes, in which a particle system would be collisionally ‘cooled’ to velocities down to millimeters per second.