Single and double ionization of magnesium by electron impact: A classical study

Abstract

International audienceWe consider electron impact-driven single and double ionization of magnesium in the 10-100 eV energy range. Our classical Hamiltonian model of these (e, 2e) and (e, 3e) processes sheds light on their total cross sections and reveals the underlying ionization mechanisms. Two pathways are at play in single ionization: Delayed and direct. In contrast, only the direct process is observed in double ionization, ruling out the excitation-autoionization channel. We also provide evidence that the so-called TS2 (Two-Step 2) mechanism predominates over the TS1 (Two-Step 1) mechanism, in agreement with experiments

Double-ionization mechanisms of magnesium driven by electron impact

“…However, the model in Ref. [32] differs from the model in this paper in two ways; first, the atom consists of an ionic core and two valence shell electrons only, and second, a soft-Coulomb potential without effective charge governs the electron-core potential. Appropriately adjusting the soft-Coulomb parameters a and b alone guarantees no self ionization and non-empty ground states in the twoelectron model in Ref.…”

“…In this section, we compare our model and its implications with the two bound electron model of Mg in Ref. [32]. This comparison will highlight the importance of considering an inner shell electron and the importance of fully accounting for all electron-electron correlations with the inner shell electron.…”

“…Ref. [32] considers a two-active electron model to study the single and double ionization of Mg by electron impact. Ref.…”

“…Ref. [32] also uses a purely classical mechanical approach to describe the double ionization processes and all electron-electron correlations taken into account. However, the model in Ref.…”

“…In Sec. IV, we conclude with two points of discussion; first, about the similarities and differences between our three-active electron target atom and a two-active electron target atom [32] for Mg, and, second, about the experimental link of the mechanisms predicted by this model.…”