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Title: Behavior of molecular hydrogen exposed to strong dc, ac, or low-frequency laser fields. II. Comparison of ab initio and Ammosov-Delone-Krainov rates

Journal Article · · Physical Review. A
 [1]
  1. Fachbereich Chemie, Universitaet Konstanz, Fach M 721, D-78 457 Constance (Germany)

Ionization rates are calculated for molecular hydrogen oriented parallel to an external electric or low-frequency electromagnetic field using a three-dimensional, fully correlated ab initio method. The calculation includes also the range of field intensities where barrier suppression leads to over the barrier instead of tunneling ionization. The resulting ionization rates (considering also the influence of vibrational motion and excitation) are compared to those predicted by the (semiclassical) Ammosov-Delone-Krainov (ADK) model. In agreement with earlier findings for helium it is found that the ADK model predicts very accurately ionization rates in the tunneling regime, but overestimates the rate in the over-the-barrier regime. This conclusion is, however, only true, if the tunnel-ionization rate of H{sub 2} is (at least to a good approximation) isotropic.

OSTI ID:
20632458
Journal Information:
Physical Review. A, Vol. 66, Issue 6; Other Information: DOI: 10.1103/PhysRevA.66.063408; (c) 2002 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
Country of Publication:
United States
Language:
English