# FS-FLASH

 2018-04-1815:22 [PUBDB-2018-01787] Journal Article et al Multidimensional photoemission spectroscopy—the space-charge limit New journal of physics 20(3), 033004 - (2018) [10.1088/1367-2630/aaa262]   Photoelectron spectroscopy, especially at pulsed sources, is ultimately limited by the Coulomb interaction in the electron cloud, changing energy and angular distribution of the photoelectrons. A detailed understanding of this phenomenon is crucial for future pump–probe photoemission studies at (x-ray) free electron lasers and high-harmonic photon sources. [...] OpenAccess: PDF PDF (PDFA); 2018-01-1210:42 [PUBDB-2018-00596] Journal Article et al Short-wavelength free-electron laser sources and science: a review Reports on progress in physics 80(11), 115901 - (2017) [10.1088/1361-6633/aa7cca]   This review is focused on free-electron lasers (FELs) in the hard to soft x-ray regime. The aim is to provide newcomers to the area with insights into: the basic physics of FELs, the qualities of the radiation they produce, the challenges of transmitting that radiation to end users and the diversity of current scientific applications. [...] Restricted: PDF PDF (PDFA); 2018-01-1113:05 [PUBDB-2018-00478] Journal Article et al Momentum-resolved photoelectron absorption in surface barrier scattering on Ir(111) and graphene/Ir(111) Physical review / B 96(15), 155108 (2017) [10.1103/PhysRevB.96.155108]   Time-of-flight momentum microscopy reveals sixfold symmetric sharp features of decreased intensity (dark lines) in constant-energy maps for clean Ir(111) and graphene/Ir(111). The dark lines have been observed for $p$- and $s$-polarized light in the photon-energy range of 20–27 eV and result from scattering of photoelectrons at the surface potential barrier [...] OpenAccess: PDF PDF (PDFA); 2018-01-1013:15 [PUBDB-2018-00331] Journal Article et al Spin-filtered time-of-flight $k$-space microscopy of Ir – Towards the “complete” photoemission experiment Ultramicroscopy 183, 19 - 29 (2017) [10.1016/j.ultramic.2017.06.025]   The combination of momentum microscopy (high resolution imaging of the Fourier plane) with an imaging spin filter has recently set a benchmark in k-resolution and spin-detection efficiency. Here we show that the degree of parallelization can be further increased by time-of-flight energy recording. [...] OpenAccess: PDF PDF (PDFA); Restricted: PDF PDF (PDFA); 2018-01-1013:13 [PUBDB-2018-00329] Journal Article et al Vectorial spin polarization detection in multichannel spin-resolved photoemission spectroscopy using an Ir(001) imaging spin filter Physical review / B 95(10), 104423 (2017) [10.1103/PhysRevB.95.104423]   We report on spin- and angular-resolved photoemission spectroscopy using a high-resolution imaging spin filter based on a large Ir(001) crystal enhancing the effective figure of merit for spin detection by a factor of over 10$^3$ compared to standard single-channel detectors. Furthermore, we review the spin filter preparation and its lifetime [...] OpenAccess: PDF PDF (PDFA); 2018-01-0916:34 [PUBDB-2018-00300] Journal Article et al Hosting of surface states in spin–orbit induced projected bulk band gaps of W(1 1 0) and Ir(1 1 1) Journal of physics / Condensed matter 29(25), 255001 - (2017) [10.1088/1361-648X/aa7173]   Spin-momentum locking of surface states has attracted great interest in recent years due to envisioned technological applications in the field of spintronics. Normal metal surfaces like W(1 1 0) and Ir(1 1 1) show surface states with energy dispersions and spin-polarization textures, which are reminiscent of topologically non-trivial surface states. [...] Published on 2017-05-24. Available in OpenAccess from 2018-05-24.: PDF PDF (PDFA); Restricted: PDF PDF (PDFA); 2018-01-0916:17 [PUBDB-2018-00296] Journal Article et al High-resolution resonant inelastic extreme ultraviolet scattering from orbital and spin excitations in a Heisenberg antiferromagnet Physical review / B 96(18), 184420 (2017) [10.1103/PhysRevB.96.184420]   We report a high-resolution resonant inelastic extreme ultraviolet (EUV) scattering study of the quantum Heisenberg antiferromagnet KCoF$_3$. By tuning the EUV photon energy to the cobalt M$_{23}$ edge, a complete set of low-energy 3d spin-orbital excitations is revealed [...] OpenAccess: PDF PDF (PDFA); 2017-12-1811:00 [PUBDB-2017-13615] Contribution to a conference proceedings et al Status of the Soft X-Ray Free Electron Laser FLASH 8th International Particle Accelerator Conference, IPAC2017, Meeting locationCopenhagen, Denmark, 14 May 2017 - 19 May 2017 JACoW, Geneva, Switzerland, 3 pp. (2017) [10.18429/JACoW-IPAC2017-WEPAB025]   The superconducting free-electron laser user facility FLASH at DESY in Hamburg, routinely produces several thousand photon pulses per second. The operational parameters cover a wavelength range from 90 nm down to 4 nm with pulse energies from several $\mu$J up to 1 mJ and with pulse durations of several hundred fs down to a few fs. [...] OpenAccess: PDF PDF (PDFA); External link: Fulltext 2017-12-1810:52 [PUBDB-2017-13612] Poster et al Status of the Soft X-Ray Free Electron Laser FLASH 8th International Particle Accelerator Conference, IPAC2017, Meeting locationCopenhagen, Denmark, 14 May 2017 - 19 May 2017   The superconducting free-electron laser user facility FLASH at DESY in Hamburg, routinely produces several thousand photon pulses per second. The operational parameters cover a wavelength range from 90 nm down to 4 nm with pulse energies from several $\mu$J up to 1 mJ and with pulse durations of several hundred fs down to a few fs. [...] OpenAccess: PDF PDF (PDFA); 2017-12-1114:25 [PUBDB-2017-13262] Journal Article et al THz pulse doubler at FLASH: double pulses for pump–probe experiments at X-ray FELs Journal of synchrotron radiation 25(1), 39 - 43 (2018) [10.1107/S1600577517015442]   FLASH, the X-ray free-electron laser in Hamburg, Germany, employs anarrowband high-field accelerator THz source for unique THz pump X-rayprobe experiments. However, the large difference in optical paths of the THzand X-ray beamlines prevents utilization of the machine’s full potential (e.g.extreme pulse energies in the soft X-ray range). [...] OpenAccess: PDF PDF (PDFA);