Hannover 2013 – scientific programme
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A: Fachverband Atomphysik
A 7: Interaction with VUV and X-ray light I
A 7.2: Talk
Monday, March 18, 2013, 14:15–14:30, B 302
Electron emission following collective autoionization of He nanodroplets irradiated by intense XUV pulses — •Yevheniy Ovcharenko1, Viktor Lyamayev2, Raphael Katzy2, Michele Devetta3, Aaron LaForge2, Oksana Plekan4, Patrick O'Keeffe5, Robert Richter4, Tommaso Mazza6, Michele Di Fraia7, Nils-Benedict Brauer8, Marcello Coreno5, Paola Finetti4, Paolo Piseri3, Marcel Drabbels8, Stefano Stranges9, Kevin Prince4, Carlo Callegari4, Frank Stienkemeier2, and Thomas Möller1 — 1Technische Universität Berlin, Germany — 2Universität Freiburg, Germany — 3University of Milan, Italy — 4Sincrotrone Trieste, Italy — 5CNR-IMIP Rome, Italy — 6European XFEL GmbH, Germany — 7University of Trieste, Italy — 8EPFL Lausanne, Switzerland — 9University of Rome "Sapienza", Italy
The narrow bandwidth and tunability of FERMI@Elettra seeded FEL (Free Electron Laser) open new areas in the study of ultrafast radiation-matter interaction. Using this unique source with high-brilliance femtosecond XUV-pulses, photoelectron spectroscopy of He-nanodroplets has been performed by velocity map imaging technique in the photon energy range 20-27 eV. The electron spectra show that ionization occurs not only by a direct process at photon energies above the ionization potential (IP) but also below the threshold. It was found that electron spectra below IP strongly depend on the total energy absorbed by nanodroplets and give evidence for a collective autoionization process with energy transfer between neighboring atoms.