Many-Body Effects in Energetic Atomic Transitions

Abstract

When a target atom is bombarded with a beam of energetic photons, electrons, heavy charged particles, or other atoms, one or more of the atomic electrons from the target atom may be ejected or excited to different orbits. In many of these atomic processes, the quantitative study of the transition based on the straightforward independent-particle calculation, when compared with the experimental measurement, fails to provide a satisfactory physical interpretation. The failure of the independent-particle calculation suggests that the interaction to be considered should not be limited to the one between the incident particle and the ejected or excited electron alone. A more comprehensive quantitative estimation should also include interactions between (i) the ejected or the excited electron and the remaining electrons of the target atom, (ii) the incident particle and the remaining electrons of the target atom, and (iii) electrons within the target atom at various stages of the transition.