Two-photon double ionization of He is studied at the Free Electron Laser in Hamburg (FLASH) by inspecting He2+ momentum (P-(He 2+)) distributions at 52 eV photon energy. We demonstrate that recoil ion momentum distributions can be used to infer information about highly correlated electron dynamics and find the first experimental evidence for 'virtual sequential ionization'. The experimental data are compared with the results of two calculations, both solving the time-dependent Schrodinger equation. We find good overall agreement between experiment and theory, with significant differences for cuts along the polarization direction that cannot be explained by the experimental resolution alone.
"Differential Cross Sections for Non-Sequential Double Ionization of He by 52 EV Photons from the Free Electron Laser in Hamburg, Flash," New Journal of Physics, vol. 12, pp. 1 - 17, Institute of Physics - IOP Publishing, Jul 2010.
The definitive version is available at https://doi.org/10.1088/1367-2630/12/7/073035
Keywords and Phrases
Differential cross section; Dinger equation; Double ionization; Experimental data; Experimental evidence; Highly correlated electrons; Photon energy; Polarization direction; Recoil-ion momentum distribution; Sequential ionization; Time-dependent; Two-photon double ionization; Free electron lasers; Particle detectors; Photoionization
International Standard Serial Number (ISSN)
Article - Journal
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01 Jul 2010