Dresden 2011 – wissenschaftliches Programm
A 26.45: Poster
Donnerstag, 17. März 2011, 16:00–18:30, P2
Angular correlations in the two-photon decay of helium-like heavy ions — A. Surzhykov1,2, A Volotka3, F. Fratini1,2, J.P. Santos4, P. Indelicato5, T. Stöhlker1,2, and •S. Fritzsche2,6 — 1Physikalisches Institut, Universität Heidelberg, Germany — 2GSI Helmholtzzentrum für Schwerionenforschung, Germany — 3Technische Universität Dresden, Germany — 4Departamento de Física, Universidade Nova de Lisboa, Portugal — 5Laboratoire Kastler Brossel, Paris, France — 6Department of Physics, University of Oulu, Finland
The two-photon decay of high-Z, helium–like ions has been studied theoretically in the framework of second-order perturbation theory and the Dirac equation, with emphasis placed especially on the angular emission of the two photons. In this work, we explored how the angular correlation function depends on the shell structure of the ions in their initial and final states as well as how the terms beyond the electric-dipole approximation affect the angular emission. Detailed calculations were performed for the two–photon decay of the 1s2s 1S0, 1s2s 3S1 and 1s2p 3P0 states of helium-like xenon Xe52+, gold Au77+ and uranium U90+ ions. Our results display a strong dependence of the photon emission pattern with regard to the symmetry and parity of initial and final ionic states .
 A. Surzhykov et al., Phys. Rev. A 81 (2010) 042510.