On mechanism of low-energy heavy ions scattering on a target surface with small atomic mass

In the present work, an experimental study of low-energy (E0=20-500 eV) heavy Cs+ ions scattering on target surfaces with small atomic masses (Al, Si, Ni) has been performed for more accurate definition of mechanism of scattering and evaluation of an opportunity for use of heavy ions scattering as a tool of surface layer analysis. It is shown that the dependence of the relative energies of scattered ions versus the initial energy E/E0 (E0) for Si (Eb=4.64 eV/atom) and Ni (Eb=4.43 eV/atom) approximately coincide despite the fact that the mass of Ni atom is twice as large as that of the Si atom mass. At the same time their binding energies Eb are approximately equal to each other. It is found that the scattering angles of Cs+ ions considerably exceed a limiting scattering angle θlim in a single collision. It has been established that the scattering of low-energy heavy ions by light targets is described by a non-binary mechanism of many-particle interactions (simultaneous ion interaction with several target atoms). It has been shown that during the many-particle interactions the structure of energy spectra disappears; high relative energy of scattering ions and their dependence on energy of bombardment is observed. It has been found that the energy of scattered ions depends on binding energy, melting temperature and packing density of target atoms