Osnabrück 2002 – scientific programme
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MO: Molekülphysik
MO 15: Photoionisation II (gemeinsam mit FV Atomphysik)
MO 15.2: Talk
Thursday, March 7, 2002, 14:15–14:30, HS 15/E10
Spin polarization of resonant Auger in Ar — •Bernd Lohmann1,2, U. Kleimann2, György Snell3, Burkhard Langer4, S. Kanton3, Nora Berrah3, M. Martens5, and Uwe Becker1 — 1Fritz-Haber-Institut der MPG, Faradayweg 4-6, 14195 Berlin, Germany — 2Institut für Theoretische Physik, Universität Münster, 48149 Münster, Germany — 3Department of Physics, Western Michigan University, Kalamazoo, USA — 4Max-Born-Institut, Max-Born-Str.2A, 12489 Berlin, Germany — 5Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
We report here on the first spin resolved detection of the resonant Auger electron following Ar 2p → 4s excitation along with corresponding calculations performed by a relaxed orbital method within the relativistic distorted wave approximation. Using linearly and circularly polarised synchrotron radiation we measured the transferred and the dynamical spin polarisation of the resonant Auger electrons. Due to the partial wave composition of these lines, high values for the transferred and low values for the dynamical spin polarisation are expected. Dynamical spin polarisation may be considered as the inverse process of circular dichroism in the angular distribution of photoelectrons from aligned atoms. Therefore, it gives no rise to net effects such as the transferred spin polarisation does. Besides the alignment, large dynamical spin polarisation requires the existence of more than one partial wave with a large phase difference between them. The small dynamical spin polarisation for most Auger transitions due to vanishing relativistic phase shifts indicate that the relativistic interactions in the continuum are also small.