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MO: Molekülphysik
MO 15: Photoionisation II (gemeinsam mit FV Atomphysik)
MO 15.7: Talk
Thursday, March 7, 2002, 15:30–15:45, HS 15/E10
High-resolution photoelectron emission from oriented N2 molecules — •Rainer Hentges1, Daniel Rolles1, Georg Prümper1, Alexander Golovin2, and Uwe Becker1 — 1Fritz-Haber-Institut der MPG, Faradayweg 4-6, 14195 Berlin, Germany — 2Petersburg State University, Institute of Physics, Petrodvorets, 198904 St. Petersburg, Russia
Photoionization of homonuclear molecules, in particular of their innermost 1s shells, is a showcase of the coherent superposition of photoelectron waves from two spatially separated atomic sites. There is a very successful approximation of core level photoelectron and Auger electron emission, the one center approximation, which considers the electron emission as being strongly localized. The resulting electron angular distribution is therefore calculated as an incoherent sum of electron waves emitted from both atomic sites. On the other hand, there is evidence for a splitting of the 1s photoelectron lines into gerade and ungerade components [1], a clear signature of delocalized and coherent electron emission. However, model calculations show that if the two components are not resolved, the photoelectron angular distributions in the molecule frame are the same for both cases. Therefore only a high resolution measurement of the molecule frame angular distribution can distinguish between these two models. We have performed such an experiment for N2 at beamline BW3 of HASYLAB. The results are presented and discussed with respect to the coherence properties of the emitted N2: N(1s) photoelectrons.
[1] U. Hergenhahn et al., J. Phys. Chem. A 105, 5704 (2001).