Electronic excitation effects on secondary ion emission from a foil of conducting material bombarded by high energy heavy ions

Abstract

It is recognized that high electronic excitations play an important role in the damage process of solid targets by high-energy heavy ions. However, the conversion mechanism of the energy of the excited electrons into kinetic energy for target atom displacement is not well understood. In order to investigate the electronic excitation effects of high energy heavy ions in solids, we have studied the secondary ions mass spectra from thin conductive solid targets irradiated by swift heavy ion beams from the JAERI tandem accelerator in the energy region where the electronic stopping power is dominant. The results show the importance of the electronic excitation effect even in simple metallic (Cu) target. It is suggested that Coulomb explosion is the major mechanism of producing columnar defects along the incident ion path.