Melting temperature effects on the size of ion-induced craters

Recent work on the sizes of craters produced by ion impacts of solids has s hown that the size of the crater scales with the inverse square of the cohe sive energy. This observation is in contrast to the size of craters produce d in macroscopic impacts, which scale directly with the inverse of the cohe sive energy. It has relied on the assumption that the melting temperature i s proportional to the cohesive energy. Using computer simulations, we now s how that the size scales in fact with the inverse of the product of the mel ting temperature and cohesive energy. This provides direct proof that the r eason to the different behavior of macroscopic and ion-induced cratering is flow of the liquid produced by the ions. (C) 2001 American Institute of Ph ysics.