Non-Perturbative Theory of Atomic Ionization with Two-Electron Continuum

A long-term objective of this project is to develop a general method for calculating atomic ionization leading to a final state with two-electron continuum. The theory of such processes should account for the inter-electron interaction between the two outgoing electrons and between each of these electrons with the ion core. A non-perturbative approach to the inter-electron interaction is to be taken by solving the Lippmann-Schwinger equation. The interaction with the core is described within the Hartree-Fock approximation.

Principal Investigator

Anatoli Kheifets
Electron Physics Unit, RSPhysSE
Australian National University

Project

x01

RFCD Codes

240300

Significant Achievements, Anticipated Outcomes and Future Work

The close-coupling theory of the multiple atomic ionization has been further extended. The second-order corrections to the electron- and proton-impact ionization have been estimated in the double ionization of the helium atom. By employing a single-center model, the double photoionization of hydrogen molecule was described in good agreement with experiment. Significant progress has been achived in theoretical description of the double photoionization of outer shell of noble gas atoms. The work is currently underway to incorporate the Floquet theory of the laser-atom interaction into the model.

 

Computational Techniques Used

System of non-linear integral equations, known as Lippmann-Schwinger equations, is solved on a discrete grid Large RAM and extensive parallelisation are used for this purpose. In addition, access to BLAS and LAPACK library routines as well as NAG Fortran Mathematical Libraries is very beneficial.

 

Publications, Awards and External Funding

External Funding and Awards

ARC Discovery grant DP0451211, Two-electron atomic photoionization in superstrong electromagnetic field

Publications

P. Bolognesi, A.S. Kheifets, I. Bray, L. Malegat, P. Selles, A K Kazansky and L. Avaldi, A procedure to extract the amplitudes of He photodouble ionisation and their relative phase from experimental data, J. Phys. B 36(16): L241-L247, 2003
A. S. Kheifets and I. Bray, Double shake-off model for triple photoionization of beryllium, J. Phys. B 36(13): L211-L217, 2003
A. Dorn, A. S. Kheifets, C.D. Schröter, C.Höhr, G. Sakhelashvili, R. Moshammer, J. Lower and J. Ullrich, Appearance and disappearance of the second Born effects in the (e, 3e) reaction on He, Phys. Rev. A 58:012715, 2003