Theory of excitation-ionization by particle impact

Techniques developed to include correlation in the double excitation of atoms are applied to a second two-electron process, excitation-ionization by projectile impact. The atomic wave function is approximated by a sum of products of one-electron wave functions, with the coefficients chosen by diagonalizing the fully correlated many-electron Hamiltonian. Thus, spatial correlation is included in both the asymptotic and scattering regions by using these Configuration Interaction (CI) wave functions for initial, intermediate, and final states. Both the energy-conserving and energy-nonconserving parts of the second-order amplitude are found, so that time-ordering effects are also included. Comparison is made with the experimental results of Fulling et al