title: Hidden charge states in soft-x-ray laser-produced nanoplasmas revealed by fluorescence spectroscopy.
abstract: Highly charged ions are formed in the center of composite clusters by strong free-electron laser pulses and they emit fluorescence on a femtosecond time scale before competing recombination leads to neutralization of the nanoplasma core. In contrast to mass spectrometry that detects remnants of the interaction, fluorescence in the extreme ultraviolet spectral range provides fingerprints of transient states of high energy density matter. Spectra from clusters consisting of a xenon core and a surrounding argon shell show that a small fraction of the fluorescence signal comes from multiply charged xenon ions in the cluster core. Initially, these ions are as highly charged as the ions in the outer shells of pure xenon clusters with charge states up to at least 11+.
authors.affiliation: Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Schroedter
authors.affiliation: Institut für Optik und Atomare Physik, Technische Universität Berlin, Eugene-Wigner-Building EW 3-1, Hardenbergstrasse 36, 10623 Berlin, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Müller
authors.affiliation: Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Kickermann
authors.affiliation: Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Przystawik
authors.affiliation: Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Toleikis
authors.affiliation: Institut für Optik und Atomare Physik, Technische Universität Berlin, Eugene-Wigner-Building EW 3-1, Hardenbergstrasse 36, 10623 Berlin, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Adolph
authors.affiliation: Institut für Optik und Atomare Physik, Technische Universität Berlin, Eugene-Wigner-Building EW 3-1, Hardenbergstrasse 36, 10623 Berlin, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Flückiger
authors.affiliation: Institut für Optik und Atomare Physik, Technische Universität Berlin, Eugene-Wigner-Building EW 3-1, Hardenbergstrasse 36, 10623 Berlin, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Gorkhover
authors.affiliation: Institut für Optik und Atomare Physik, Technische Universität Berlin, Eugene-Wigner-Building EW 3-1, Hardenbergstrasse 36, 10623 Berlin, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Nösel
authors.affiliation: Institut für Optik und Atomare Physik, Technische Universität Berlin, Eugene-Wigner-Building EW 3-1, Hardenbergstrasse 36, 10623 Berlin, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Krikunova
authors.affiliation: Institut für Optik und Atomare Physik, Technische Universität Berlin, Eugene-Wigner-Building EW 3-1, Hardenbergstrasse 36, 10623 Berlin, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Oelze
authors.affiliation: Institut für Optik und Atomare Physik, Technische Universität Berlin, Eugene-Wigner-Building EW 3-1, Hardenbergstrasse 36, 10623 Berlin, Germany.
authors.forename: Y
authors.initials: Y
authors.lastname: Ovcharenko
authors.affiliation: Institut für Optik und Atomare Physik, Technische Universität Berlin, Eugene-Wigner-Building EW 3-1, Hardenbergstrasse 36, 10623 Berlin, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Rupp
authors.affiliation: Institut für Optik und Atomare Physik, Technische Universität Berlin, Eugene-Wigner-Building EW 3-1, Hardenbergstrasse 36, 10623 Berlin, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Sauppe
authors.affiliation: Institut für Optik und Atomare Physik, Technische Universität Berlin, Eugene-Wigner-Building EW 3-1, Hardenbergstrasse 36, 10623 Berlin, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Wolter
authors.affiliation: SLAC National Accelerator Laboratory, P.O. Box 20450, Stanford, California 94309, USA.
authors.forename: S
authors.initials: S
authors.lastname: Schorb
authors.affiliation: SLAC National Accelerator Laboratory, P.O. Box 20450, Stanford, California 94309, USA.
authors.forename: C
authors.initials: C
authors.lastname: Bostedt
authors.affiliation: Institut für Optik und Atomare Physik, Technische Universität Berlin, Eugene-Wigner-Building EW 3-1, Hardenbergstrasse 36, 10623 Berlin, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Möller
authors.affiliation: Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany and The Hamburg Centre for Ultrafast Imaging CUI, Luruper Chaussee 149, 22761 Hamburg, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Laarmann