SWIFT HEAVY-ION-INDUCED PLASTIC-DEFORMATION

Electronic energy loss, which dominates the slowing down of swift heav y ions in solids, leads to atomic rearrangements depending on the natu re of the irradiated target. Amorphous materials are subject to struct ural changes similar to those observed in crystalline materials and un dergo anisotropic plastic deformation. The former process occurs at th e beginning of the irradiation while the latter one takes place above an incubation fluence depending on the nature of the target. This plas tic deformation consists of a steady increase of the sample dimensions perpendicular to the ion-beam direction together with a decrease of t he dimension parallel to it, at constant volume.