ABOVE-SURFACE NEUTRALIZATION OF SLOW N6+ IONS DURING INTERACTIONS WITH A CU(001) TARGET

Measurements are reported for projectile K-Auger-electron emission, ob served at 90-degrees to the incident beam direction, during interactio ns of 60-keV N6+ ions with a clean Cu(001) target at grazing incidence angles in the range 0.2-degrees-20-degrees. Spectral features in the projectile K-Auger-electron spectra consistent with above-surface K-Au ger-electron emission were observed at perpendicular velocities below 1.37 X 10(-2) a.u. (incidence angle psi < 1.9-degrees). At incidence a ngles below 0.8-degrees (nu(perpendicular-to) < 5.8 X 10(-3) a.u.) the above-surface K Auger yields were observed to saturate, reaching a ma ximum value of about 12% of the total K-Auger-electron production. The present results are in good agreement with earlier measurements.