Femtosecond dynamics - snapshots of the early ion-track evolution (vol 225, pg 4, 2004)

The energy dissipation and femtosecond dynamics 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 by means of Auger-electron spectroscopy. Results for amorphous Si, amorphous C and polypropylene are presented and discussed. Experimental evidence for a highly charged track region as well as for hot electrons inside tracks is shown. As follows mainly from Auger-electron spectroscopy, there are strong indications for different track-production mechanisms in different materials. (C) 2004 Elsevier B.V. All rights reserved.