Heidelberg 2015 – wissenschaftliches Programm
A 38.8: Vortrag
Freitag, 27. März 2015, 13:00–13:15, C/HSW
Excitation energy transfer processes in Ar dimers below the Interatomic Coulombic decay (ICD) threshold probed with XUV-pump IR-probe experiments — •Tomoya Mizuno, Philipp Cörlin, Andreas Fischer, Michael Schönwald, Thomas Pfeifer, and Robert Moshammer — Max-Planck-Institut für Kernphsik, Heidelberg, Germany
We investigated the mechanism of transferring excitation energy to a neighbouring atom in Ar dimers below the ICD threshold by using XUV-pump IR-probe experiments. The first XUV pulse, which is generated from 10 fs IR laser pulse via HHG in Ar gas, creates two different types of excited states in one of two Ar atoms, such as a 3s inner-shell vacancy and 3d excitation state (Ar 3p−2(3P)3d 2P and 2D) following 3p valence ionization by shake-up process. And then, the delayed IR probe pulse further ionizes into a repulsive Ar+(3p−1) and Ar+(3p−1) state after a variable time delay. Finally, all charged reaction products emerging from the Ar dimer were detected by a reaction microscope. The apparatus enables us to record the kinetic energy release (KER) of a Ar+ +Ar+ ion-pair as a function of the pump-probe delay, in order to discuss the internuclear distance R at a given time. We found that the delay-dependent KER spectra exhibit clearly two dissociation pathways, corresponding to decay of 3s inner-shell ionization channel and shake-up channel, respectively. Moreover it was also found that the excitation energy is transferred to a neighbouring atom at the crossing points due to nonadiabatic transition.