Multiple-scattering analysis of triply differential cross sections for electron emission in energetic ion-atom collisions

The role of multiple-scattering events has been investigated in single ioni zation of atoms induced by energetic ion impact. The triply differential cr oss sections have been evaluated as a function of the projectile scattering angle for fixed values of the emitted electron energy and angle within the framework of the distorted-wave Born approximation (DWB). It has been show n that the double-scattering mechanism, which (sometimes) results in a char acteristic double-scattering peak at a definite projectile scattering angle , provides a satisfactory description of the process over a wide region of electron ejection energies and angles. For low-energy electron emission the role of higher orders is not negligible, and the quantum mechanical nature of the process is more emphasized. At an electron velocity equal to the pr ojectile velocity the analogy with the mechanism of electron capture into b ound states has also been investigated, In this region the DWB theory for i onization corresponds to the Oppenheimer-Brinkman-Kramers model for electro n capture.