Explosive developments in microelectronics, interest in nuclear metallurgy, and widespread applications in surface science have all produced many advances in the field of ion implantation. The research activity has become so intensive and so broad that the field has become divided into many specialized subfields. An Advanced Study Institute, covering the basic and common phenomena of aggregation, seems opportune for initiating interested scientists and engineers into these various active subfields since aggregation usually follows ion implantation. As a consequence, Drs. Perez, Coussement,...