CC BY-NC-SA 3.0 UnportedPietzsch, A.Föhlisch, A.Beye, M.Deppe, M.Hennies, F.Nagasono, M.Suljotil, E.Wurth, W.Gahl, C.Dörich, K.Melnikov, A.2020-08-122020-08-122008https://doi.org/10.34657/4133https://oa.tib.eu/renate/handle/123456789/5504We have performed core level photoelectron spectroscopy on a W(110) single crystal with femtosecond XUV pulses from the free-electron laser at Hamburg (FLASH). We demonstrate experimentally and through theoretical modelling that for a suitable range of photon fluences per pulse, time-resolved photoemission experiments on solid surfaces are possible. Using FLASH pulses in combination with a synchronized optical laser, we have performed femtosecond time-resolved core-level photoelectron spectroscopy and observed sideband formation on the W 4f lines indicating a cross correlation between femtosecond optical and XUV pulses. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.enghttps://creativecommons.org/licenses/by-nc-sa/3.0/530Electron spectroscopyElectronsEmission spectroscopyLaser pulsesLasersMolecular orbitalsMolecular spectroscopyOptical correlationPhotoelectricityPhotoelectron spectroscopyPhotoelectronsPhotoionizationPhotonsPulsed laser applicationsPulsed laser depositionSingle crystal surfacesSingle crystalsSpectrum analysisTungstenX ray lasersCore-level photoelectron spectroscopyCross correlationsExtreme ultraviolet (XUV) pulsesFemto secondsFemtosecond time-resolvedFemtosecond x raysFluencesFree electron laser (FEL)Optical (PET) (OPET)solid surfacesTime-resolvedTime-resolved photoemission (TRPE)X ray photoelectron spectroscopyArticle