Secondary Ion Emission from Metal Surface in Collision of 30keV Ar+ Ions

Abstract

Charge states and kinetic energies of scattered Ar ions and recoiled ions in collision of30keV Ar ions with Mn, Fe, Co, Ni, Cu, Zn, Ge, Ag, Cd, Sb, Ta, Pt, Au and Pb targets were measured at the direction of angle 70°. The targets were placed on the focal plane of the INS isotope separator. We observed the spectra consisting of sharp peaks and a continuous background. It was confirmed from the peak positions that the collisions between the incident Ar ions and the target materials are of quasi-elastic character. However, an energy difference of about500eV which can be interpreted as inelastic energy loss was observed. Cross sections of scattered ions were measured and excitation curves are discussed. In the case of Nd2O3target, we found the collisions to be considered as independent collisions of Ar ions with individual Nd and O atoms due to decomposition of the Nd2O3molecule in the ion impact. The shoulder which was always observed in the high energy side of the peak was found to be explained quantitatively as a result of double scattering. The background was discussed in terms of multiple-scattering and energy absorption in the target.