Charge state for internuclear distance of cluster constituent ions penetrating through a foil

Chiba, Atsuya; Saito, Yuichi; Narumi, Kazumasa; Yamada, Keisuke; Kaneko, Toshiaki*

Availability of the swift cluster ion is expected as new irradiation source, because the cluster ion bombardment to the solid brings irradiation effects different from the monatomic ion bombardment at the same speed. This unique effect, cluster effect, is caused via the physical processes that a number of high energy ions within a narrow spatiotemporal region make the high density excited states and that the constituent ion influences with respect to one another. For understanding of the expression mechanism of cluster effect, detailed investigation of these two physical processes are needed. In this study, with a focus on the interaction between constituent ions, we developed an analyzing method that shows quantitatively the relationship between the internuclear distance of constituent ions and their charge states, using the Coulomb explosion imaging technique, to investigate the contribution of the screened Coulomb potential to the cluster effect.