Hannover 2013 – scientific programme
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A: Fachverband Atomphysik
A 17: Interaction with strong or short laser pulses II
A 17.7: Talk
Tuesday, March 19, 2013, 15:45–16:00, B 302
Time-resolved imaging of ulra-fast collective electron motion in argon — •Lutz Fechner1, Nicolas Camus1, Thomas Pfeifer1, Joachim Ullrich1,2, and Robert Moshammer1 — 1Max-Planck-Institut für Kernphysik, Heidelberg — 2Physikalisch-Technische Bundesanstalt, Braunschweig
Using a pump-probe scheme for sequential double ionization of Ar-atoms in strong few-cycle laser pulses we prepare and probe electronic Spin-Orbit Wavepackets in singly charged Ar-ions1. As a result of the first ionization step, a multi-electron bound-state wavepacket is launched in the ion that gives rise to a time-delay dependant Ar+→Ar++ yield for ionization within the second pulse2 and thus allows us to probe the electronic motion as a function of time. Performing Ar++/2e− triple-coincidence measurements utilizing a Reaction Microscope (REMI) we obtain kinematically complete, time-resolved photoelectron spectra. This enables us to uncover the periodic redistribution of population in different electronic orbitals and hence the multi-electron dynamics. A comparison of the experimental data with simple model calculations supports our interpretation. In addition, the method enables us to extract state-selective information about the tunnelling process itself.
[1] H.J. Wörner & P.B. Corkum, J. Phys. B 44 (2011), 041001
[2] A. Fleischer et al., Phys. Rev. Lett. 107 (2011), 113003