Dust Aggregation on Surfaces*

The physics underlying the manner in which small particulates (i.e., dust) accumulate on surfaces is crucial to our understanding of dust contamination within fusion environments as well as its role in the formation of early protoplanets and the future of space exploration. Unfortunately, the manner in which dust (whether charged or not) interacts with a surface is poorly understood. This presentation will describe an experiment investigating the accumulation of dust on an insulating surface placed within a vacuum environment. It will be shown that under these conditions, small dust particles can form Compact Aggregate Piles (CAPs). The appearance of CAPs indicates that dust accumulation is sensitive to a variety of forces, the combination of which can lead to different evolutionary paths for the system. The physics behind this process, and the mechanism by which charge is accumulated on these particles will be discussed as will their role in CAP formation. Alternative formation mechanisms that may be involved will also be examined.