ANGULAR AND CHARGE-STATE DISTRIBUTIONS OF HIGHLY-CHARGED IONS SCATTERED DURING LOW-ENERGY SURFACE-CHANNELING INTERACTIONS WITH AU(110)

Abstract

We have measured scattered projectile angular and charge state distributions for 3.75 keV/amu O-q+ (3 less than or equal to q less than or equal to 8) and 1.2 keV/amu Ar-q+ (3 less than or equal to q less than or equal to 14) ions grazingly incident along the [110] and [100] directions of a Au(110) single crystal target. Scattered projectile angular distributions characteristic of surface channeling are observed. For both incident species, the dominant scattered charge fraction is neutral, which varies only by a few percent as a function of incident charge state. Significant O- formation is observed, which manifests a distinct velocity threshold. For incident Ar projectiles with open L-shell, the positive scattered charge fractions, while always less than about 10%, increase linearly with increasing number of initial L-shell vacancies.