Queen's University Belfast | School of Mathematics & Physics | Applied Mathematics & Theoretical Physics
Centre for Theoretical Atomic, Molecular and Optical Physics (CTAMOP)

picture of hugoDr H W van der Hart
(Hugo van der Hart)

  Contact Information

  • Postal address
    • Dr H W van der Hart
      Dept of Applied Mathematics and Theoretical Physics
      David Bates Building
      Queen's University Belfast
      Belfast, BT7 1NN
      Northern Ireland
      United Kingdom

  • Telephone +44 (0)28 9097 6048 (direct line)
  • Telephone +44 (0)28 9097 6001/2 (departmental office)
  • Fax +44 (0)28 9097 6061
  • email h.vanderhart@qub.ac.uk
  • Official homepage
  Within Queen's University

  Research Interests
  • The R-matrix Floquet approach for multiphoton processes
    My main interest is the theoretical study of many-electron systems embedded in strong laser fields. One of the techniques used at present is the R-matrix-Floquet approach . This approach has been developed during the 1990's and is one of the leading methods for the investigation of multiphoton processes. Recent highlights of applications of R-matrix-Floquet theory include

    • Excellent agreement with fully independent time-dependent calculations for ionization rates of He at 390 nm. Agreement is typically within 10% for a process requiring absorption of at least 9 photons.
    • Two-photon double ionization of He for photon energies between 40 and 48 eV. R-matrix Floquet theory was a pioneering technique for this process, which is now a focal point for theoretical and experimental investigation.
    • Two-photon emission of inner-shell electrons when complex atoms are irradiated by VUV (free-electron) laser light. We have studied emission of a 1s electron from Li-. We have also established that emission of a 2s electron from Ne+ in the 1s22s22p5 ground state is a very important two-photon ionization process.

  • Time-dependent R-matrix approach
    The R-matrix-Floquet approach can not be used to describe the response of atoms to ultra-short light fields, since it assumes the pulse to be infinitely long. We are therefore developing a time-dependent R-matrix approach. The first application of this technique was to study Ar atoms in intense few-cycle pulses. From the behaviour of the wavefunction, we were able to obtain ionization in excellent agreement with those obtained using the R-matrix-Floquet approach, thereby demonstrating the accuracy of this new technique.

  • Recollision model calculations
    A different approach to investigating the behaviour of atoms in strong laser fields is through the application of model calculations. These calculations cannot provide detailed results, but they provide insight into the physics of many-electron atoms in strong laser fields.

  • B-spline basis set techniques
    I am also highly interested in the development and application of B-spline techniques for atomic physics calculations. B-spline basis sets are very well suited for high-accuracy calculations. These sophisticated basis sets have been applied to study the following properties of two- and three-electron atoms :

    • Energies
    • Radiative lifetimes
    • Autoionization lifetimes
    • Electron scattering
    • Photoionization
    • Double photoionization
    • Triple photoionization

    For an overview of research publications, please visit my official homepage.


This page was last updated on Mon 28 January 2008
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