Elastic energy loss and defect dynamics under swift heavy ion bombardment

Abstract

A heavy multicharged ion (MCI) moving in solids interacts with nuclei and electrons of the matter atoms. At a projectile velocity exceeding the Bohr velocity V > V 0 the main process is inelastic interaction, i.e. excitation and ionization of bound electrons. The elastic interaction being the result of electrostatic repulsion of the MCI nucleus and the target atom nucleus is the key mechanism in the point defect production in the whole velocity range. The well-known method of the elastic interaction cross-section calculation in the velocity range V < V 0 is modified for the velocity range V > V 0 when the projectile is a MCI. The elastic interaction cross-section is obtained by taking into account the velocity dependence of the MCI charge and in accordance with the screening length which is a function of velocity V too. The attenuation of the screening effect leads to a marked rise of the defect production cross-section. The elastic energy loss increase is hardly distinguished from the well-known results. It is shown that the cooling of excited electrons can be described by the nonlinear heat conduction equation with an analytical solution. The possible mechanism for latent track formation is discussed.