Momentum distributions of ionization products in ion-atom collisions

Abstract

Final state momentum distributions of the projectile, the recoil-ion, and the emitted electron in ion-atom ionizing collisions are examined. New theoretical results using the continuum distorted wave-eikonal initial state (CDW-EIS) approximation are reported for He ionization by proton impact at high and intermediate energies. The finite value at the kinematical threshold in the longitudinal recoil-ion momentum distribution is shown to be considerably enhanced at intermediate energies. The transverse recoil-ion momentum distribution is calculated by considering the internuclear interaction. At higher energies, the longitudinal and transverse electron momentum distributions clearly show the binary electron contribution. The calculations prompt for further experimental work in the field.