GEV LATENT ION TRACKS IN SUGAR - FULLERENES AND OTHER RADIOCHEMICAL PRODUCTS

It is now known that fullerenes, large atomic carbon clusters, and pol ycyclic compounds, remain in the latent tracks of sufficiently energet ic ions in carbonaceous condensed matter. For the polycyclic compound production a characteristic threshold of a few eV/Angstrom(3) in trans ferred electronic energy must be exceeded. For more general and especi ally more quantitative purposes, sugar was selected as the ion beam ta rget for the experiments described. Sugar is readily dissolved, and ra diochemical products along the ion track are accessible for quantitati ve assessement. We report an observation of the genesis of the singula r fullerenes C-60 and C-70 in ion tracks, and we present a simple theo retical model for fullerene growth from a primeval soup. Specifically, we found in 3 GeV U20+ ion tracks the production of 53 to 114 C-60 mo lecules, and about 3 C-70 molecules per track. Additionally a variety of other radiochemical products emerges, which are characterized by e. g. C=C double bonds, cyclic rings and even pentagons. For contrast, CH 2- and CH3- groups, normally very pronounced in sugar, vanish. Finally , there are indications for the emergence of either carbon cluster or polymer formation.