Heidelberg 2015 – wissenschaftliches Programm
A 29.3: Vortrag
Donnerstag, 26. März 2015, 11:45–12:00, C/HSW
Theoretical calculation of above-threshold ionization of xenon involving the giant dipole resonance — •Antonia Karamatskou1,2, Robin Santra1,2, Tommaso Mazza3, and Michael Meyer3 — 1Center for Free-Electron Laser Science, DESY, Hamburg, Germany — 2Universität Hamburg, Hamburg, Germany — 3European XFEL GmbH, Hamburg, Germany
We present a theoretical study on above-threshold ionization (ATI) of xenon in the photon energy range between 100 and 150 eV. Our numerical method relies on the exact solution of the Schrödinger equation within the time-dependent configuration interaction singles scheme (TDCIS). Within TDCIS it is possible to include and distinguish certain electronic correlation effects that are mediated by Coulomb interaction. In this way, the influence of collectiveness on the process studied can be quantified. Analyzing the 2-photon ATI cross section we find that, in contrast to the 1-photon ionization case, in the nonlinear regime two distinct resonance states underlying the giant dipole resonance can be resolved. The existence of two energy poles was predicted already in the 70's by Wendin [J.Phys. B At. Mol. Opt. Phys. 6, 42 (1973)]. We compare our theoretical results to recent measurements performed at the free-electron laser FLASH in Hamburg, which provided nonlinear electron-spectroscopy data on xenon in the XUV energy range.
This work was supported by the Deutsche Forschungsgemeinschaft under Grant No. SFB 925/A5.