Attosecond electron-electron collision dynamics of the four-electron escape in Be close to threshold

TL;DR

This study investigates the four-electron escape dynamics in beryllium near the ionization threshold, revealing a pyramid-shaped escape pattern and elucidating the underlying collision mechanisms using attosecond techniques.

Contribution

It uncovers a new pyramid-shaped escape geometry for four electrons in Be and demonstrates the physical mechanisms behind quadruple ionization with attosecond collision analysis.

Findings

Electrons escape in a pyramid configuration instead of a tetrahedron.

Attosecond collision scheme aligns with the pyramid break-up pattern.

Provides insight into quadruple ionization mechanisms.

Abstract

We explore the escape geometry of four electrons a few eV above threshold following single-photon absorption from the ground state of Be. We find that the four electrons leave the atom on the vertices of a pyramid instead of a previously-predicted tetrahedron. To illustrate the physical mechanisms of quadruple ionization we use a momentum transferring attosecond collision scheme which we show to be in accord with the pyramid break-up pattern.