Formulation of the Binary-Encounter Approximation in Configuration Space and Its Application to Ionization by Light Ions

The binary-encounter approximation (BEA) is transformed from momentum space to configuration space. In this frame the impact-parameter representation allows one to calculate a variety of quantities pertinent to the general problem of ionization. Among these are cross sections for proton ionization of hydrogen and helium; in the latter case, cross sections for ejection of both electrons are also given. A number of tables and formulas are given, enabling one to correct the simple hydrogenlike-model predictions of the BEA for effects which arise in multielectron atoms. Multiple-ionization probabilities ($K+L$ shell) are calculated and compared to experimental results and to the predictions of the semiclassical approximation.