Differential cross-section measurements of charge-changing processes in small-impact-parameter collisions by 900-keV ${\mathrm{Ar}}^{\mathrm{q}+}$ (q=0–3) ions on He atoms were studied. Both scattered and recoiled particles were separated according to their charges and detected by a kinematical coincidence system. The distribution of the number of ejected electrons from the colliding system was also evaluated. A weak correlation between the charge-state distributions of the emerging projectile and recoil ions at a fixed impact parameter has been determined. This is not in contradiction to other measurements in which larger correlations were found and were attributed to the impact-parameter selection effect.

• Received 1 August 1988

DOI:https://doi.org/10.1103/PhysRevA.39.2899