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arXiv · 1803.06063

Simulation of angular resolved RABBITT measurements in noble gas atoms

Alexander W. Bray·Faiza Naseem·Anatoli S. Kheifets
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Abstract

We simulate angular resolved RABBITT (Reconstruction of Attosecond Beating By Interference of Two-photon Transitions) measurements on valence shells of noble gas atoms (Ne, Ar, Kr, and Xe). Our non-perturbative numerical simulation is based on solution of the time-dependent Schrödinger equation for a target atom driven by an ionizing XUV and dressing IR fields. From these simulations we extract the angular dependent magnitude and phase of the RABBITT oscillations and deduce the corresponding angular anisotropy β parameter and Wigner time delay $τ_W$ for the single XUV photon absorption which initiates the RABBITT process. Said β and $τ_W$ parameters are compared with calculations in the random phase approximation with exchange (RPAE) which includes inter-shell correlation. This comparison is used to test various effective potentials employed in the one-electron TDSE. In lighter atoms (Ne and Ar), several effective potentials are found to provide accurate simulation of RABBITT measurements for a wide range of photon energies up to 100 eV above the valence shell threshold. In heavier atoms (Kr and Xe), the onset of strong correlation with the d-shell restricts the validity of the single active electron approximation to several tens of eV above the valence shell threshold.

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Alexander W. Bray, Faiza Naseem, Anatoli S. Kheifets. 2018-04-27. Simulation of angular resolved RABBITT measurements in noble gas atoms. https://doi.org/10.1103/physreva.97.063404

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