Table of Contents
Journal of Atomic, Molecular, and Optical Physics
Volume 2010 (2010), Article ID 231329, 7 pages
http://dx.doi.org/10.1155/2010/231329
Research Article

Distorted Wave Theories Applied to Double Ionization by Ion Impact: Simulation of Higher-Order Processes

1Institute of High Performance Computing, 1 Fusionopolis Way, #16-16 Connexis, Singapore 138632
2Department of Physics and Astronomy, York University, 4700 Keele Street, Toronto, ON, Canada M3J 1P3
3Department of Physics and Laboratory for Atomic, Molecular, and Optical Research, Missouri University of Science and Technology, Rolla, MO 65409, USA
4Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany

Received 14 January 2010; Accepted 24 March 2010

Academic Editor: Igor Bray

Copyright © 2010 M. F. Ciappina et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

One of the goals in studies of double ionization (DI) of simple atoms by electron or ion impact is to elucidate and assess the different mechanisms that lead to this atomic process. In this work we present an attempt to model the mechanisms beyond the first order in DI of helium by highly charged projectiles. To this end we employ the continuum distorted wave-eikonal initial state (CDW-EIS) formalism joint with a Monte Carlo event generator (MCEG). The MCEG allows us to generate theoretical event files that represent the counterpart of the data obtained from a kinematically complete experiment. Starting from these event files, a new data analysis tool used to contrast theory and experiment in DI, the four-body Dalitz plots, is easily produced. The higher order mechanisms are simulated by considering DI as a sequential process: a single ionization of a helium atom as a first step and another single ionization of a single-charged helium ion as a second step. Some of the features in the experimental data are very well reproduced by these simulations.