Interaction of atomic and molecular MeV ions with surface

Secondary ion emission was studied using atomic and molecular ions bombarding organic and metallic targets. The energy of the projectile ions varied from 200 keV to 3 MeV. Relative yields of positive and negative secondary ions desorbed from phenylalanine and aluminum targets were identified by time-of-flight mass spectrometry. Cq+, Oq+, Nq+, CO+ and CO+2 (0 ≤ q ≤ 7) were the beams used in this study. The yield obtained for [M-H]-, [M + H]+ and H- and H+ secondary ions indicate the existence of two mechanisms for the desorption process: the kinetic and the surface mechanism. (orig.)