• Correlated ionization processes in atoms and molecules 

      Askeland, Sigurd (Doctoral thesis; Peer reviewed, 2013-09-27)
      This thesis is composed of five scientific papers written between 2009 and 2013. The focus of this work is on various photo-ionization processes in small atoms and molecules. The strong field phenomenon called “atomic ...
    • Dynamics in the H2+ molecule, using a one dimensional model 

      Askeland, Sigurd (Master thesis, 2009-06-02)
      A 1D model of the hydrogen molecular ion in the Born-Oppenheimer (BO) approximation. The making and testing of the model is described, as well as some underlying theory. The model also calculates non-BO effects.
    • Multiphoton ionization and stabilization of helium in superintense xuv fields 

      Sørngård, Stian Astad; Askeland, Sigurd; Nepstad, Raymond; Førre, Morten (Peer reviewed; Journal article, 2011)
      Multiphoton ionization of helium is investigated in the superintense field regime, with particular emphasis on the role of the electron-electron interaction in the ionization and stabilization dynamics. To accomplish this, ...
    • Probing two-center interference in H2+ using chirped pulses 

      Askeland, Sigurd; Førre, Morten (Peer reviewed; Journal article, 2013)
      The influence of intermediate resonant dissociative channels in the few-photon ionization dynamics of H+2 is demonstrated in a pump-probe scenario. Two-photon ionization of H+2 by two sequentially applied pump and probe ...
    • Stabilization of circular Rydberg atoms by circularly polarized infrared laser fields 

      Askeland, Sigurd; Sørngård, Stian Astad; Pilskog, Ingjald; Nepstad, Raymond; Førre, Morten (Peer reviewed; Journal article, 2011-09-29)
      The ionization dynamics of circular Rydberg states in strong circularly polarized infrared (800 nm) laser fields is studied by means of numerical simulations with the time-dependent Schr¨odinger equation. We find that at ...
    • Two-photon double ionization of helium by attosecond laser pulses: Evidence of highly correlated electron motion 

      Askeland, Sigurd; Nepstad, Raymond; Førre, Morten (Peer reviewed; Journal article, 2012)
      We apply a recently developed ab initio numerical framework to investigate the angular distributions of the emitted electrons in the immediate proximity of the threshold for the two-photon double ionization of helium. ...