37 research outputs found
Relativistic and retardation effects in the two--photon ionization of hydrogen--like ions
Full text linkThe non-resonant two-photon ionization of hydrogen-like ions is studied in
second-order perturbation theory, based on the Dirac equation. To carry out the
summation over the complete Coulomb spectrum, a Green function approach has
been applied to the computation of the ionization cross sections. Exact
second-order relativistic cross sections are compared with data as obtained
from a relativistic long-wavelength approximation as well as from the scaling
of non-relativistic results. For high-Z ions, the relativistic wavefunction
contraction may lower the two-photon ionization cross sections by a factor of
two or more, while retardation effects appear less pronounced but still give
rise to non-negligible contributions.Comment: 6 pages, 2 figure
Variational principle for high-order perturbations with application to multiphoton processes for the H atom
Full text linkIonization of atomic hydrogen with up to four excess photons by circularly and linearly polarized light
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Two-photon ionisation of excited atomic hydrogen at the photoelectric threshold and above
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Above Threshold Ionization of Hydrogen Atom in Strong ac Fields
Full text linkUsing a Sturmian function expansion non-perturbative method is applied to calculate above threshold ionization of hydrogen atom in a laser field.</jats:p
