Scattering of slow highly charged ions from solid surfaces

This thesis is based on experimental investigations of scattering of slow highly charged ions (HCIs) from solid surfaces. We used Ar q+ (1 ≤ q ≤ 15) ions with 4 keV kinetic energy and v ≈ 0.06 a.u. velocity scattered from a clean Au(111) single crystal surface at different incident angles (5° ≤ 0 ≤ 37.5°) and scattering angles of 75° and 50°. The charge state and energy distributions of the scattered ions after interaction with the surface were analyzed. In these studies, we found that the yield of multiply charged scattered Ar ions increases by about 3 orders of magnitude when L-shell is opened (q ≥ 9). For large incident angles (ψ ≥ 25°), the measured energy spectra exhibit a peak with the value expected for binary elastic scattering. While, at a small incidence angle of 5°, inelastic energy loss was identified in spite of the large scattering angle. We also measured the angular dependence of energy loss for 32 keV Ar9+ ions scattered grazingly from a Au(111) and a LiF(100) surface. Whereas a weak angular dependence of energy loss of scattered Ar ions from the Au surface, the energy loss increases strongly with increasing scattering angles when the Ar ions are scattered from the LiF surface. For interpretation of these experimental results they are compared with model calculations taking into account the processes of side-feeding into Ar inner shells, recapture to the surface, Auger transitions, image charge acceleration and fraction force from a flux of electrons between acceleration and fraction force from a flux of electrons between ion and surface.