Berlin 2014 – wissenschaftliches Programm

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A: Fachverband Atomphysik

A 26: Poster: Interaction of matter and collisions with ions

A 26.6: Poster

Dienstag, 18. März 2014, 16:30–18:30, Spree-Palais

Refinement of the Basis for the Solution of the Two-Centre Dirac Equation Employing the Finite Basis Set Approach — •Walter Hahn — Institut für theoretische Physik, Universität Heidelberg, Germany

The solution of the Dirac equation for an electron in the presence of two spatially fixed nuclei is a necessary step for understanding the formation of quasi-molecules in collisions of highly-charged heavy ions and the accompanying creation of lepton pairs. In a previous work, we have shown a numerical solution of this Dirac equation by employing the finite basis set approach together with a basis constructed from B-splines. In this work, we propose two issues for the improvement of the previous results. First, we enlarge the basis by functions found to be essential, which go beyond the B-spline ansatz. We achieve an increase of accuracy, which holds for almost all low-energy bound states and all distances between the two centres, and in some specific cases amounts to several orders of magnitude. Arguments aiming to explain this increase of accuracy are presented. Second, we employ the dual kinetic-balance basis in order to avoid non-physical spurious states. An accurate solution of the problem presented constitutes a cornerstone on the road towards tests of QED in super-critical fields.