Angular distributions for the electron-impact single ionization of sodium and magnesium

Abstract

We present angular distributions for the electron-impact single ionization of sodium and magnesium at intermediate incident electron energies. The results are obtained from a full-dimensionality solution of the two-active-electron time-dependent Schrödinger equation using the time-dependent close-coupling method. We compare calculated angular distributions with existing measurements. We find good overall agreement with measurements over a range of incident electron energies in both cases. We also calculate angular distributions for ejection configurations in which no measurements are currently available.

Theoretical and experimental(e,2e)study of electron-impact ionization of laser-aligned Mg atoms

“…The TDCC calculations presented here have been discussed in detail previously [14]. The TDCC method centers around the propagation of a two-electron wavefunction that accounts for the interaction between the incoming electron and the ionized electron of the target.…”

Evidence for unnatural-parity contributions to electron-impact ionization of laser-aligned atoms

“…Our two-electron TDCC calculations used a radial mesh of (960) 2 points with variable mesh spacing of between 0.01 and 0.2 a.u. [24]. We found that it was necessary to include partial wave contributions from L = 0 − 14 to completely converge our calculations.…”

“…(5) corrects a typographical error in the denominator of Eq. (9) of [24]. The function P LS l 1 l 2 (k 1 , k 2 , T ) is formed by projecting the final two-electron radial wavefunction (after propagation to a sufficiently long time T ) P LS l 1 l 2 (r 1 , r 2 , t = T ) onto the one-electron continuum orbitals.…”

“…The time-dependent close-coupling (TDCC) theory as applied to electron-impact ionization has been well described [22,23]. The extension of the method to treat multi-electron systems, by utilizing an orthogonalization to the filled sub-shells at each time step, was presented recently for calculations for the single ionization of ground-state Mg [24]. The calculations presented here follow this procedure, except that the active electron is now the 3p orbital of Mg.…”

“…The calculations presented here follow this procedure, except that the active electron is now the 3p orbital of Mg. The Mg + [Ne]3s core is the same as used in our previous calculations from the ground state [24]. We note that this approach is effectively a configuration-average approach to electron-impact ionization, that is, we consider only the 3p active orbital as a configuration and do not account for the term splitting of the 3s3p Mg configuration into the 1 P and 3 P terms.…”