ON THE SHATTERING OF CLUSTERS BY SURFACE IMPACT HEATING

The onset of a shattering regime when a supersonic cluster undergoes a n ultrafast heating by its impact at a surface, proposed on the basis of an information theoretic analysis, has now been demonstrated experi mentally for molecular clusters. It is emphasized that the sudden onse t of shattering as a function of impact velocity is a robust result de pending essentially only on the multitude of possible isomers of large r clusters. There is one underlying assumption of the information theo retic approach-namely that there is a rather rapid thermalization of t he translational degrees of freedom of the impact heated cluster so th at mean energy is the only energetic constraint. When this is not nece ssarily the case, e.g., for ionic clusters at lower energies, there wi ll not be extensive fragmentation. (C) 1996 American Institute of Phys ics.