HCI-Induced Ionization and Fragmentation of Fullerenes and Organic Molecules

Abstract

The interaction of multiply charged ions with fullerenes is governed by electron capture as well as nuclear and electronic stopping. The fullerene excitation due to electronic stopping leads mainly to direct ionization and multifragmentation. Our experiments show that the according patterns in the fragmentation spectra can serve as fingerprints for the electronic stopping. A quantitative analysis of the cross sections for ionization and multifragmentation reveals the characteristic linearity in the projectile velocity v as well as an oscillatory dependence on the projectile atomic number Z. The π-electron dominated electronic structure of fullerenes has some similarities to that of biomolecular species. Qualitatively similar dynamics are therefore expected to occur in HCI collisions with biomolecules. First experimental results indeed indicate a strong dependence of the fragmentation pattern on projectile charge state and velocity.