Berlin 2005 – wissenschaftliches Programm
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A: Atomphysik
A 7: Atoms and Ions in Ultra Short and Strong laser Fields I
A 7.3: Fachvortrag
Samstag, 5. März 2005, 09:15–09:30, HU 3094
Transverse momentum balance in strong-field ionization of atoms — •Artem Rudenko1, Karl Zrost1, Claus Dieter Schröter1, Bernold Feuerstein1, Thorsten Ergler1, Vitor L.B. de Jesus2, Robert Moshammer1, and Joachim Ullrich1 — 1Max-Planck-Institut für Kernphysik, Heidelberg, Germany — 2Centro Federal de Educacao Tecnologica, Rio de Janeiro, Brasil
The motion of reaction fragments emerging from ionization of atoms in strong linearly polarized laser fields is naturally separated into a longitudinal part, which is parallel to the field polarization, and a transverse part, perpendicular to the field. Since the laser field does not act in the transverse direction, the analysis of electron and ion transverse momenta is particularly suited to explore the role of the final-state Coulomb interaction between one or more electrons as well as the parent ion. Using a Reaction-Microscope we performed high-resolution measurements of transverse momentum distributions of ions and electrons for single and multiple ionization of atoms by intense ultrashort (7-25 fs) laser pulses. For single ionization, the experimental distributions exhibit a sharp cusp at zero transverse momentum, similar that observed in ion-atom collisions but in contradiction to a Gaussian shape predicted by standard tunneling theory [1]. The results are in good agreement with recent semiclassical calculations [2], where it was shown that the cusp appears due to the Coulomb interaction of the outgoing electron with its parent ion. In addition, results for double and multiple ionization will be presented.
[1] N.B. Delone and V.P. Krajnov, Phys. Usp. 41, 469 (1998)
[2] K. Dimitriou et al, Phys. Rev. A, in press (2004)