Corrugation effects in oxygen surface trapping at hyperthermal energies

We have measured trapping probabilities for 5-600 eV O+ ions incident on Cu (001) at 45 degrees and along the sample normal. These results have been re produced using classical trajectory simulations. In the simulations, the su rface trapping probability P-s is distinguished from the total trapping pro bability P-T At 45 degrees, the energy dependence of P-s differs significan tly from that of Na+ incident on Cu(001). Trajectory analysis shows that di fferences between the trapping trends can be attributed to differences in t he apparent surface corrugation for these two systems.