title: Slow-down collisions and nonsequential double ionization in classical simulations.
abstract: We use classical simulations to analyze the dynamics of nonsequential double-electron short-pulse photoionization. We utilize a microcanonical ensemble of 10(5) two-electron "trajectories," a number large enough to provide large subensembles and even sub-subensembles associated with double ionization. We focus on key events in the final doubly ionized subensemble and back-analyze the subensemble's history, revealing a classical slow-down scenario for nonsequential double ionization. We analyze the dynamics of these slow-down collisions and find that a good phase match between the motions of the electrons can lead to very effective energy transfer, followed by escape over a suppressed barrier.
authors.affiliation: Rochester Theory Center for Optical Science and Engineering and Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, USA.
authors.forename: R
authors.initials: R
authors.lastname: Panfili
authors.forename: S L
authors.initials: SL
authors.lastname: Haan
authors.forename: J H
authors.initials: JH
authors.lastname: Eberly