Stuttgart 2012 – wissenschaftliches Programm
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A: Fachverband Atomphysik
A 2: Atomic systems in external fields I
A 2.4: Vortrag
Montag, 12. März 2012, 11:15–11:30, V57.05
The time-dependent two-centre Dirac equation: Beyond the monopole approximation — •Sean McConnell1,2, Anton Artemyev1,2, Manuel Mai1,2, and Andrey Surzhykov1,2 — 1Universität Heidelberg — 2GSI, Darmstadt
The realisation of the extreme fields generated by heavy quasi-molecules has been of great interest since at least the early 1970’s. As such, solutions to the two-centre time-dependent Dirac equation is of utmost importance. A number of approaches have already been made, particularly by the group of Greiner, using the coupled channel equation, to generate solutions to this challenging theoretical problem. In spite of the progress made in the spherically symmetric coordinate system, solutions to the time-independent equation using the coupled channel approach have only been performed for the monopole approximation to the two centre potential. Although the monopole approximation indeed provides very good results for small internuclear distances, its applicability at larger internuclear distances is questionable. Therefore, we present in this contribution, an extension of the work already performed toward the use of higher multipoles in the potential expansion. We have calculated, using the B-Spline method in a dual kinetically balanced basis, cross sections for the collision of two U+91 U92 atoms. To prove the value of our approach we have also determined cross sections of ionisation using this method with those procured using perturbation theory as implemented elsewhere [1]. Applications to laser assisted collisions will also be discussed.
[1] S R McConnell, J. Phys. B: At., Mol., Phys. 44 (2011) 145204