München 2004 – wissenschaftliches Programm
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A: Atomphysik
A 11: Photoionisation I
A 11.7: Vortrag
Dienstag, 23. März 2004, 18:00–18:15, HS 132
Partial cross sections of doubly excited helium below the N=7 ionization threshold — •Yuhai Jiang1,2, Ralph Püttner1, Rainer Hentges3, Jens Viefhaus3, Uwe Becker3, Jan-Michael Rost2, and Günter Kaindl1 — 1Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin — 2Max-Planck-Institut für Physik Komplexer Systeme, Nöthnitzer Str. 38, 01187 Dresden — 3Fritz-Haber-Institut, Faradayweg 4-6, 14195 Berlin
Partial photoionization cross sections (PCSs), σn, leading to final ionic states of helium, He+(n), were measured at BESSY II in the region of doubly excited helium up to the ionization threshold I7 of He+ [1]. The experiments were performed with a time-of-flight (TOF) electron spectrometer and high photon resolution, Δ E≅ 6 meV. The results of these measurements are a most critical assessment of the decay dynamics of double-excitation resonances and agree well with those of recent eigenchannel R-matrix calculations. The mirroring behavior in the PCSs predicted recently by Liu and Starace [2] is only partially observed. By discussing the formulas given by these authors in a more general context, the behavior of the PCSs of helium with respect to mirroring can be understood.
[1] Y. H. Jiang, R. Püttner, R. Hentges, J. Viefhaus, M. Poiguine, U. Becker, J. M. Rost, and G. Kaindl, Phys. Rev. A (submitted).
[2] Ch.-N. Liu and A. Starace, Phys. Rev. A 59, R1731 (1999).