Heidelberg 2015 – wissenschaftliches Programm
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A: Fachverband Atomphysik
A 33: Collisions, scattering and recombination
A 33.4: Vortrag
Donnerstag, 26. März 2015, 15:15–15:30, C/kHS
Angle-resolved properties of characteristic x-rays as a tool for determining small level splittings in highly charged ions — •Zhongwen Wu1,2, Nikolay Kabachnik3,4, Andrey Surzhykov1, Chenzhong Dong2, and Stephan Fritzsche1,5 — 1Helmholtz Institute Jena, Germany — 2Northwest Normal University, China — 3European XFEL, Germany — 4Lomonosov Moscow State University, Russia — 5University of Jena, Germany
The angular distribution and the photon-photon angular correlation of x-ray emissions have been studied for two-step
radiative cascades that proceed via overlapping intermediate resonances. Special attention was placed especially upon
the questions of how the level splitting of the intermediate resonances affects the x-ray emissions and whether
angle-resolved measurements can help determine small splittings in the level structure of highly charged ions. As an
example, detailed computations within the multiconfiguration Dirac-Fock method were performed for the two-step cascade
1s2p2 Ji=1/2, 3/2 → 1s2s2p J=1/2, 3/2 + γ1 → 1s22s
Jf=1/2 + γ1 + γ2 of lithium-like ions, for which a level crossing of the two 1s2s2p
J=1/2, 3/2 intermediate resonances occurs in the range 74 ≤ Z ≤ 79. A remarkably strong effect associated
with finite lifetime and level splitting of these intermediate resonances was found for the angular distribution and
the photon-photon angular correlation. We therefore suggest that accurate angle-resolved measurements of x-ray
emissions may serve as a tool for determining small level splittings [1].
[1] Z. W. Wu et al., Phys. Rev. A 90, 052515 (2014).