NEGATIVE-ION PRODUCTION IN MULTICHARGED ION-SURFACE INTERACTIONS

Measurements are presented of energy and angular resolved reflected charge state distributions for O-q+, q=1-7, and N-q+, q=2-7, incident projectiles scattered from a clean Al(110) single crystal surface. The measurements were carried out at 16 keV incident ion energy, and at 1.2 degrees grazing incidence. O- reflected ions were observed for all incident O projectile charge states. The energy loss of O- reflected particles was found to be consistently larger than for reflected O+ particles, which was in turn larger than for higher reflected charge states. The magnitude of the energy loss was found to be independent of the incident projectile charge. The reflected charge state distributions were also found to be independent of the incident charge state, except when projectile K shell vacancies were initially present.