Hannover 2010 – wissenschaftliches Programm
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A: Fachverband Atomphysik
A 4: Photoionization I (exchanged with A1)
A 4.2: Vortrag
Montag, 8. März 2010, 17:00–17:15, F 303
Signatures of the complex classical dynamics in the spectrum of highly doubly excited states of two-electron atoms — •J. Eiglsperger, M. Schönwetter, and J. Madroñero — Physik Department, Technische Universität München, Germany
Close to the break-up threshold of two-electron atoms the spectrum is strongly influenced by the underlying classical mixed regular-chaotic dynamics and typical signatures of quantum chaos, e.g., Ericson fluctuations or scaling laws [1] for the fluctuations of the photoionization cross section (PCS), are expected to become observable.
Computations for the PCS of He and Li+ have been performed to test the charge dependent exponent of the scaling law in [1]. A comparison of experimental data with the planar model reveals a quantitative agreement for the PCS of helium. PCS calculated up to the 25th single ionization threshold exhibit fluctuations. These are mainly due to a dominant series of resonances which can be associated with an approximate quantum number F=N−K in accordance with 3D full calculations and experimental observations [2]. As the energy increases, the dominant role of a single series as sole contributor is apparently lost as new series start to contribute significantly to the cross sections. This would result in an earlier onset of Ericson fluctuations [3] than in the picture of a single dominant series, where the onset is expected around I34.
[1] C. W. Byun et al., Phys. Rev. Lett. 98, 113001 (2007).
[2] Y. H. Jiang et al., Phys. Rev A 78, 021401 (2008).
[3] J. Eiglsperger and J. Madroñero, Phys. Rev A 80, 022512 (2008).