Double ionization by electron impact is a process involving at least three active electrons in interaction with a targeted parent ion. Already, it is challenging to analyze and even compute measurable observables in this reduced dynamical system. However, in the experimental measurements of [P. McCallion et al. (1992)], a clear knee structure is observed in the double ionization cross section of magnesium, unpredictable by three active electron models. This knee structure is actually a manifestation of the more deeply bound electrons in the targeted atom: electrons from the inner shell. In this framework, we have derived a purely classical model which accounts for at least one electron from the inner shell. In this project, the local and statistical analysis of the trajectories in the four active electrons system allowed us to shed lights on the dominant processes involved in the double ionization of magnesium by electron impact and the mechanism beyond the origin of the knee structure in the double ionization cross sections.

Publication

• • S. Mittal, J. Dubois, C. Chandre, T. Uzer, Double ionization mechanisms of magnesium driven by electron impact, Physical Review A 101, 062707 (2020)