Laser-induced nonsequential double ionization at and above the recollision-excitation-tunneling threshold

Journal Article · Tue Jun 15 04:00:00 EDT 2010 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.81.063413· OSTI ID:21437922

Shaaran, T; Nygren, M T ^[1]

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1. Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom)

We perform a rigorous, semianalytic study of the recollision excitation with subsequent tunneling ionization (RESI) mechanism in laser-induced nonsequential double ionization (NSDI), based on the strong-field approximation. We show that the shapes of the electron momentum distributions carry information about the bound state with which the first electron collides, the bound state to which the second electron is excited, and the type of electron-electron interaction. Furthermore, one may define a driving-field intensity threshold for the RESI physical mechanism. At the threshold, the kinetic energy of the first electron, upon return, is just sufficient to excite the second electron. We compute the distributions for helium and argon in the threshold and above-threshold intensity regimes. In the latter case, we relate our findings to existing experiments. The electron momentum distributions encountered are symmetric with respect to all quadrants of the plane spanned by the momentum components parallel to the laser-field polarization, instead of concentrating on only the second and fourth quadrants. The above-mentioned momentum constraints, together with the strong dependence of the distributions on the bound states involved, may be important for singling out the RESI mechanism in actual physical situations and using NSDI in ultrafast imaging.

• OSTI ID: 21437922
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 6 Vol. 81; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
APPROXIMATIONS
ARGON
ATOM COLLISIONS
BOUND STATE
CALCULATION METHODS
COLLISIONS
DISTRIBUTION
ELECTROMAGNETIC RADIATION
ELECTRON COLLISIONS
ELECTRON-ATOM COLLISIONS
ELECTRON-ELECTRON COLLISIONS
ELECTRONS
ELEMENTARY PARTICLES
ELEMENTS
ENERGY
ENERGY-LEVEL TRANSITIONS
EXCITATION
FERMIONS
FLUIDS
GASES
HELIUM
IONIZATION
KINETIC ENERGY
LASER RADIATION
LEPTONS
NONMETALS
POLARIZATION
RADIATIONS
RARE GASES
TUNNEL EFFECT