Dependence of scattered ion yield on the incident energy: Ne+ on pure gallium and indium

An experimental study of the ion yield dependence on the incident energy (0.4–2.2 keV) for Ne+ isotopes scattered at 120° from pure gallium and indium targets has been carried out by mass-resolved ion-scattering spectrometry. For both two targets, the ion yield curves exhibited a broad maximum below 0.8–1 keV (with a lower position for Ne+ on In) followed by a monotonous decrease yield without any oscillatory features. The energy dependence of ion-survival probability was explained as a complex interplay of the Auger neutralization with the characteristic velocity vc=(0.9±0.1)×107 cm/s for Ne+ on Ga, and the collision-induced neutralization and reionization. The later ones were significant processes at the energies larger than 0.8–1.0 keV or, in terms of the distance of closest approach, d0.5–0.55 Å; the collision-induced neutralization was more effective than the inverse process. No visible influence of isotope effect on charge exchange was found. The ion-survival probability versus the inverse ion velocity displayed an independence on the mass of Ne+ projectiles.