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R. Pazourek, J. Feist, S. Nagele, A. Kaltenbäck, E. Persson, B. I. Schneider, L. A. Collins, J. Burgdörfer:
"Streaking of Shake-Up Ionization";
Vortrag: Workshop "Quantum Dynamic Imaging", Montreal, Canada; 19.10.2009 - 23.10.2009.

The question whether there is a time delay between electrons liberated from an atom with or without shake-up excitation of the remaining ion has recently become a topic of interest. In this contribution we investigate whether such an apparent "time delay" can be extracted using XUV-IR streaking setups. The classical interpretation of a streaking experiment states that the release time of an electron can be directly mapped to the momentum shift which the electron acquires from the IR pulse. However, the interpretation of any apparent "delay" extracted from simulations requires great care. In particular, the ionization and shake-up process itself can be influenced by the IR field, leading to additional momentum shifts on the electron which are not related to any time delay. We investigate this problem for the helium atom, for which it is possible to solve the full six-dimensional time-dependent Schrödinger equation ab initio including all correlation effects. In our contribution we will address the influence of different pulse parameters and extraction methods of the momentum shift and discuss whether a time delay between electrons ejected with or without shake-up can be unambiguously extracted.
Work supported by the FWF-Austria, grant SFB016, and NSF, TeraGrid grant TG-PHY090031.

attosecond helium streaking