Charge States of Ne and Ar Ions Scattered to Large Angles by Ar Atoms for Collision Energies up to 3.0 MeV

Abstract

The impact parameter dependence of inner-shell excitations in single heavy ion-atom collisions can be determined from the final charge state of the scattered ion as a function of the scattering angle and collision energy. In our work, the final charge states for 0.15 MeV to 1.5 MeV Ne+ ion-projectiles scattered through angles from 1–20° by Ar atoms have been measured. Similar measurements for the Ar+-Ar system from 0.5 to 1.0 MeV, and for the Ar++-Ar system at 3.0 MeV, were made. When the average charge state, m, of the scattered ions is plotted as a function of the product Eoθ of the incident ion-energy and the scattering angle for these systems, m is observed to increase by one or two units for specific values of Eoθ. Because Eoθ is closely related to Ro, the distance of closest approach for the collision, these increases are indicative of inner-shell vacancies being produced through molecular orbital interaction.