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A: Fachverband Atomphysik
A 9: Interaction with strong or short laser pulses
A 9.2: Poster
Tuesday, September 21, 2021, 16:30–18:30, P
Ignition of a helium nanoplasma by pump-probe multiple ionization of a dopant core — •Cristian Medina1, Dominik Schomas1, Markus Debatin1, Ltaif Ltaif2, Robert Moshammer3, Thomas Pfeifer3, Hoque Ziaul4, Andreas Hult4, Maria Krikunova4, Frank Stienkemeier1, and Marcel Mudrich2 — 1University of Freiburg , Freiburg , Germany — 2Aarhus University, Aarhus , Denmark — 3Max-Planck-Institut für Kernphysik, Heidelberg. Germany — 4- Extreme Light Institute, Prague, Czech Rep.
Helium nanoplasmas are usually created by intense near-infrared laser pulses. After tunnel ionization of the cluster or some dopant atoms, the cluster fully avalanche-ionizes as the electrons are driven back and forth through the cluster by the laser field. We demonstrate a different scheme for igniting the nanoplasma on doped helium nanodroplets. An ultrashort X-ray pulse (FLASH-1 at DESY, Hamburg) or the 19th higher harmonics from an 800 nm pulse (ELI, Prague) first inner-shell ionizes the dopant cluster, followed by Auger decay and charge-transfer ionization of the helium shell. A second near-infrared pulse drives the nanoplasma at variable delay with respect to the pump pulse. At certain delay times, a resonance appears, indicated by an increase of the ignition probability, evidenced by the rise of He+ and He2+ ion yields, the hit rate as well as the electron kinetic energy.