title: Vacuum space charge effects in sub-picosecond soft X-ray photoemission on a molecular adsorbate layer.
abstract: Vacuum space charge induced kinetic energy shifts of O 1s and Ru 3d core levels in femtosecond soft X-ray photoemission spectra (PES) have been studied at a free electron laser (FEL) for an oxygen layer on Ru(0001). We fully reproduced the measurements by simulating the in-vacuum expansion of the photoelectrons and demonstrate the space charge contribution of the high-order harmonics in the FEL beam. Employing the same analysis for 400 nm pump-X-ray probe PES, we can disentangle the delay dependent Ru 3d energy shifts into effects induced by space charge and by lattice heating from the femtosecond pump pulse.
authors.forename: M
authors.initials: M
authors.lastname: Dell'Angela
authors.affiliation: SUNCAT Center for Interface Science and Catalysis , SLAC National Accelerator Laboratory , 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: T
authors.initials: T
authors.lastname: Anniyev
authors.forename: M
authors.initials: M
authors.lastname: Beye
authors.affiliation: LCLS, SLAC National Accelerator Laboratory , 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: R
authors.initials: R
authors.lastname: Coffee
authors.forename: A
authors.initials: A
authors.lastname: Föhlisch
authors.affiliation: Department of Physics, AlbaNova University Center, Stockholm University , SE-10691 Stockholm, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: Gladh
authors.affiliation: SUNCAT Center for Interface Science and Catalysis , SLAC National Accelerator Laboratory , 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: S
authors.initials: S
authors.lastname: Kaya
authors.affiliation: SUNCAT Center for Interface Science and Catalysis , SLAC National Accelerator Laboratory , 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: T
authors.initials: T
authors.lastname: Katayama
authors.forename: O
authors.initials: O
authors.lastname: Krupin
authors.forename: A
authors.initials: A
authors.lastname: Nilsson
authors.affiliation: SSRL, SLAC National Accelerator Laboratory , 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: D
authors.initials: D
authors.lastname: Nordlund
authors.affiliation: Linac Coherent Light Source, SLAC National Accelerator Laboratory , 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: W F
authors.initials: WF
authors.lastname: Schlotter
authors.forename: J A
authors.initials: JA
authors.lastname: Sellberg
authors.affiliation: Physics Department and Center for Free-Electron Laser Science, Universität Hamburg , 22607 Hamburg, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Sorgenfrei
authors.affiliation: Linac Coherent Light Source, SLAC National Accelerator Laboratory , 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: J J
authors.initials: JJ
authors.lastname: Turner
authors.affiliation: Department of Physics, AlbaNova University Center, Stockholm University , SE-10691 Stockholm, Sweden.
authors.forename: H
authors.initials: H
authors.lastname: Öström
authors.forename: H
authors.initials: H
authors.lastname: Ogasawara
authors.affiliation: Fritz-Haber Institute , Max Planck Society, Faradayweg 4-6, D-14195 Berlin, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Wolf
authors.affiliation: Physics Department and Center for Free-Electron Laser Science, Universität Hamburg , 22607 Hamburg, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Wurth