Europhys. Lett.
Volume 62, Number 5, June 2003
Page(s) 691 - 697
Section Atomic and molecular physics
Published online 01 May 2003
DOI: 10.1209/epl/i2003-00428-0
Europhys. Lett., 62 (5) , pp. 691-697 (2003)

Quasi-simultaneous double ionization of helium in super-intense high-frequency laser pulses

A. Staudt1, J. Prager2 and C. H. Keitel1

1  Theoretische Quantendynamik, Physikalisches Institut, Universität Freiburg Hermann-Herder-Str. 3, D-79104 Freiburg, Germany
2  Interdisziplinäres Zentrum für wissenschaftliches Rechnen, Universität Heidelberg Im Neuenheimer Feld 368, D-69120 Heidelberg, Germany

(Received 21 March 2003; accepted in final form 9 April 2003)

In super-intense laser pulses beyond the tunneling regime, non-sequential double ionization is known to be of little significance, especially due to the laser-induced Lorentz force. We show that, for such intense fields, electron-electron repulsion does still play a crucial role in the case of quasi-instantaneous double ionization with long electron-electron interaction times at short separations. For this purpose the time-dependent quantum dynamics and the angular ionization yields are investigated for a model helium atom beyond the dipole approximation.

32.80.Rm - Multiphoton ionization and excitation to highly excited states (e.g., Rydberg states).
32.80.Fb - Photoionization of atoms and ions.
42.50.Hz - Strong-field excitation of optical transitions in quantum systems; multi-photon processes; dynamic Stark shift.

© EDP Sciences 2003