Osnabrück 2002 – wissenschaftliches Programm
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A: Atomphysik
A 13: Photoionisation II (gemeinsam mit FV Molekülphysik)
A 13.8: Vortrag
Donnerstag, 7. März 2002, 15:45–16:00, HS 15/E10
Coherence Phenomena in the Photoelectron Emission from Homonuclear Molecules — •Daniel Rolles1, Rainer Hentges1, Georg Prümper1, Uwe Becker1, and Ricardo Dìez Muiño2 — 1Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, Germany — 2Donostia International Physics Center, San Sebastian, Spain
Photoelectron angular distributions (PAD’s) in the molecule frame have been calculated using the Multiple Scattering in Non-Spherical Potentials (MSNSP) approach for different orientations of the molecular axis with respect to the electric vector of the light. It is shown that using either a coherent or incoherent superposition of the electron flux from both atomic sites leads to the same angular distributions if the two symmetry components gerade and ungerade are unresolved. This has been proven by comparing to recent COLTRIMS data for the N2(1s) photoemission. However, considering the two components separately, the corresponding PAD’s are markedly different in the coherent model. When choosing the electron emission direction along the electric vector and the orientation of the molecular axis predominantly perpendicular to it, the u-component is suppressed in the PES, whereas choosing a molecular orientation at an angle of 45∘ enhances this component. Newly measured PAD’s are analysed with respect to these predictions and the results favour the coherent emission model strongly. Concerning the separate gerade and ungerade components, the results are also compared to recent TDLDA calculations for the photoelectron angular distributions from randomly oriented N2 molecules. The preliminary analysis shows very good agreement.