Ionization dynamics in fast ion-atom collisions. II. Final-state momentum distributions of the ionization products in collisions of He with bare carbon ions

Abstract

We have used the energy and angular distributions of the low-energy electron emission cross sections from the preceding paper [Lokesh C. Tribedi et al., Phys. Rev. A 58, 3619 (1998)] to derive the doubly differential final-state longitudinal momentum distributions of the electrons, recoil ions, and projectiles in ion-atom ionization for ${\mathrm{C}}^{6+}+\mathrm{H}\mathrm{e}.$ The complementary nature of the electron spectroscopy and the recoil-ion momentum spectroscopy have been investigated using a formulation based on three-body kinematics to explore the ionization dynamics in detail. The influence of the three-body ionization as well as the binary-encounter processes on the recoil-ion (and projectile) longitudinal momentum distributions has been investigated. The separation of the soft- and hard-collision branches of recoil-ion distributions is an important feature of the present technique. The present method also allows one to determine cross sections for very large electron momenta. The single- differential distributions are also derived by numerical integration of the double-differential distributions. The first Born approximation, the continuum distorted wave eikonal initial state, and the classical trajectory Monte Carlo calculations are used to explain the data.