Energy dissipation of fast heavy ions in matter

The energy dissipation due to fast heavy ions in matter is critically reviewed with emphasis on possible mechanisms that lead to material modifications. Starting from a discussion of the initial electronic energy-deposition processes, three basic mechanisms for the conversion of electronic into atomic energy are investigated. Experimental evidence for a highly charged track region as well as for hot electrons inside tracks is presented. As follows mainly from Auger-electron spectroscopy, there are strong indications for different track-production mechanisms in different materials.