The combination of recoil ion and ionized electron momentum spectroscopy provides an unparalleled method to investigate the details of ion-atom collision dynamics in kinematically complete experiments. To predict single ionization scattering behavior at the level now realized by experiment, the classical trajectory three-body Monte Carlo method has been used to obtain complete momenta information for the ionized electron, recoil ion, and projectile in the collision plane defined by the incident projectile and outgoing recoil ion. Strongly coupled systems were considered where the charge state of the projectile divided by the speed of the collision $q/v$ is greater than unity. Illustrated are 3.6-MeV/nucleon ${\mathrm{Se}}^{28+}$ and 9.5-MeV/nucleon ${\mathrm{Ni}}^{26+}$ collisions on He where experimental data are available. The theoretical results are in good agreement with these data and calculations have been performed for 165-keV/nucleon and 506-keV/nucleon ${\mathrm{C}}^{6+}+\mathrm{He}$ to compare results for the same $q/v$ perturbation strengths, but at much lower velocities. In all cases the ejected electrons are found to be preferentially emitted opposite to the recoil ion in the projectile-recoil collision plane. The 165-keV/nucleon ${\mathrm{C}}^{6+}$ spectra are especially rich in that electron capture strongly contributes to the overall electron loss process. Here, the electron capture to the continuum (ECC) spectrum is observed to have not only the known asymmetry in the longitudinal direction, but also has an almost complete asymmetry in the collision plane opposite to the recoil ion. Collision plane spectra differential in the transverse momenta of the recoil ion depict the transition from soft electrons for low transverse recoil momenta, to two-center, and ECC electrons for increasing transverse recoil ion momenta.

• Received 11 August 1997

DOI:https://doi.org/10.1103/PhysRevA.58.270