# FS-FLASH-B

 2020-01-2314:54 [PUBDB-2020-00522] Journal Article et al Time- and momentum-resolved photoemission studies using time-of-flight momentum microscopy at a free-electron laser Review of scientific instruments 91(1), 013109 - (2020) [10.1063/1.5118777] 2020-01-2311:30 [PUBDB-2020-00518] Journal Article et al Ghost imaging at an XUV free-electron laser Here we present the results of a classical ghost imaging experiment accomplished at an XUV free-electronlaser (FEL). To perform such experiment at an FEL source each x-ray pulse was transmitted through a movingdiffuser, which created a noncorrelated speckled beam. [...] Restricted: PDF PDF (PDFA); External link: Fulltext 2019-12-1214:08 [PUBDB-2019-05101] Journal Article/Contribution to a conference proceedings/Contribution to a book et al Expected Radiation Properties of the Harmonic Afterburner at FLASH2 39th International Free-Electron Laser Conference, FEL19, HamburgHamburg, Germany, 26 Aug 2019 - 30 Aug 2019   We discuss the afterburner option to upgrade the FLASH2 undulator line, at the FLASH facility in the Hamburg area, for delivering short wavelengths down to approximately 1.5 nm with variable polarization. This relatively straightforward upgrade enables us the study of the scientific cases in L- absorption edges of rare earth metals. [...] OpenAccess: PDF PDF (PDFA); External link: Fulltext 2019-11-1412:51 [PUBDB-2019-04221] Journal Article et al Polarization-sensitive reconstruction of transient local THz fields at dielectric interfaces Optica 6(11), 1431 - 1436 (2019) [10.1364/OPTICA.6.001431]   Intense THz fields can be used to excite specific low-frequency modes in condensed matter or drive confined currents in nano-structured arrays, paving the way for a new class of optoelectronic devices. The long wavelength enables spatially confined field enhancement due to interaction with metallic structures and interference effects at dielectric interfaces. [...] OpenAccess: PDF PDF (PDFA); 2019-11-0411:01 [PUBDB-2019-03870] Contribution to a conference proceedings et al Ultrafast Magnetisation Dynamics at the Low-Fluence Limit Supported by External Magnetic Fields 39th International Free-Electron Laser Conference, HamburgHamburg, Germany, 26 Aug 2019 - 30 Aug 2019 574 - 577 (2019) [10.18429/JACoW-FEL2019-THA04] special issue: "FEL19 Proceedings" (978-3-95450-210-3)   We report on ultrafast magnetisation dynamics in ferromagnetic cobalt/platinum multilayers upon pumping by near and mid to far infrared radiation, utilizing sub-100 femtosecond free-electron laser pulses. The evolution of the excited magnetic state is studied on femtosecond timescales with nanometre spatial resolution and element selectivity, employing time-resolved magnetic small-angle X-ray scattering. [...] OpenAccess: PDF PDF (PDFA); External link: Fulltext 2019-07-0917:18 [PUBDB-2019-02682] Journal Article et al Alignment of the aberration-free XUV Raman spectrometer at FLASH Journal of synchrotron radiation 26(1), 18 - 27 (2019) [10.1107/S160057751801576X]   An extreme-ultraviolet (XUV) double-stage Raman spectrometer is permanently installed as an experimental end-station at the PG1 beamline of the soft X-ray/XUV free-electron laser in Hamburg, FLASH. The monochromator stages are designed according to the Czerny–Turner optical scheme, adapted for the XUV photon energy range, with optical elements installed at grazing-incidence angles. [...] Restricted: PDF PDF (PDFA); 2019-07-0917:13 [PUBDB-2019-02681] Journal Article et al Surface structure determination by x-ray standing waves at a free-electron laser New journal of physics 21(3), 033031 (2019) [10.1088/1367-2630/aafa47]   We demonstrate the structural sensitivity and accuracy of the x-ray standing wave technique at a high repetition rate free-electron laser, FLASH at DESY in Hamburg, by measuring the photoelectron yield from the surface SiO$_2$ of Mo/Si multilayers. These experiments open up the possibility to obtain unprecedented structural information of adsorbate and surface atoms with picometer spatial and femtosecond temporal resolution [...] OpenAccess: PDF PDF (PDFA); 2019-07-0916:52 [PUBDB-2019-02679] Journal Article et al Normalized single-shot X-ray absorption spectroscopy at a free-electron laser Optics letters 44(9), 2157 - 2160 (2019) [10.1364/OL.44.002157]   A setup for dispersive X-ray absorption spectroscopy (XAS), employing a new reference scheme, has been implemented and tested at the soft X-ray free-electron laser (FEL) FLASH in Hamburg. A transmission grating was used to split the FEL beam into two copies (signal and reference). [...] OpenAccess: PDF PDF (PDFA); 2019-07-0916:47 [PUBDB-2019-02678] Journal Article et al Wavefront-propagation simulations supporting the design of a time-delay compensating monochromator beamline at FLASH2 Journal of synchrotron radiation 26(3), 899 - 905 (2019) [10.1107/S160057751900345X]   Wavefront-propagation simulations have been performed to complete the design of a monochromator beamline for FLASH2, the variable-gap undulator line at the soft X-ray free-electron laser in Hamburg (FLASH). Prior to propagation through the beamline optical elements, the parameters of the photon source were generated using the GENESIS code which includes the free-electron laser experimental data. [...] OpenAccess: PDF PDF (PDFA); Restricted: PDF PDF (PDFA); 2019-07-0916:41 [PUBDB-2019-02677] Journal Article et al Mapping ultrafast ionization of atoms and clusters with terahertz-streaking delay Physical review / A 99(4), 043423 (2019) [10.1103/PhysRevA.99.043423]   We apply THz-field streaking to temporally resolve the ultrafast ionization of neutral cluster vs atomic targets exposed to intense ultrashort soft x-ray pulses from a free-electron laser (FEL). In the experiment pristine Xe and mixed Xe/Ar clusters as well as Xe atoms are ionized in the vicinity of the $4d→ɛf$ giant resonance of Xe [...] OpenAccess: PDF PDF (PDFA);