Dust emission of mineral/ice mixtures: residue structure and dynamical parameters



In a series of experiments the particle emission from ice/dust mixtures under insolation at space conditions was investigated using an array of particle collectors and Piezo impact detectors. The dust data provide an estimate of the ratio of ice containing to ice free particles for different size ranges, indicating a decrease in the frequency of ice free particles with increasing particle size. The measurement of the main dynamical parameters of the particle emission reveals a significant interrelation of particle size, starting angle and velocity of the emission process. The near surface particle stream exhibits an internal structure of a low-speed central core of large grains superimposed by a high-speed background of small grains. Possible implications for the dynamics of a dust jet emanating from a comet nucleus are discussed.