EXPERIMENTAL STUDIES OF CASCADE PHENOMENA IN METALS

We review recent ion-irradiation experiments which have been performed to investigate the collapse of displacement cascades to dislocation l oops in a range of metals and alloys. Many of the results including th e dependencies of the collapse probabilities on irradiation temperatur e, and ion dose, energy and mass, can be explained within the framewor k of a thermal spike/cascade melting model which has been suggested by computer molecular dynamics simulations. Other aspects, such as the d ependence of collapse probabilities on the crystal structure and the e ffects of alloying and impurities, are less well understood.