STRONG SHELL EFFECTS IN THE SCATTERING OF SLOW HIGHLY-CHARGED AR IONSFROM A AU(111) SURFACE

Slow (E-kin=4 keV) highly charged Arq+ (6 less than or equal to q less than or equal to 13) ions were incident at 25 degrees on a Au(111) si ngle crystal surface. The ions scattered at an angle of 75 degrees wer e analyzed in energy and charge state. When electrons are removed from the L-shell (q greater than or equal to 9) of the incoming Ar ion the yield of multiply charged scattered ions (MCSI) increases by about 3 orders of magnitude. The yield of MCSI increases monotonously with an increasing number of initial L-shell vacancies. The experimental resul ts are compared with and interpreted by a model calculation including a side-feeding process into Ar inner shells, recapture to the surface and Auger transitions after the ion-surface interaction. [S1050-2947(9 7)00611-2].