# FS-FLASH

Latest additions:
 2017-08-0110:24 [PUBDB-2017-08778] Journal Article et al Direct 3D mapping of the Fermi surface and Fermi velocity Nature materials 16(6), 615 - 621 (2017) [10.1038/nmat4875] 2017-06-2310:06 [PUBDB-2017-05924] Journal Article et al Statistical properties of a free-electron laser revealed by Hanbury Brown?Twiss interferometry Physical review / A 95(2), 023843 (2017) [10.1103/PhysRevA.95.023843]   We present a comprehensive experimental analysis of statistical properties of the self-amplified spontaneous emission free-electron laser (FEL) FLASH by means of Hanbury Brown and Twiss interferometry. The experiments were performed at FEL wavelengths of 5.5, 13.4, and 20.8 nm [...] OpenAccess: PDF PDF (PDFA); 2017-06-0817:06 [PUBDB-2017-04558] Journal Article et al Communication: Direct evidence for sequential dissociation of gas-phase Fe(CO)$_5$ via a singlet pathway upon excitation at 266 nm The journal of chemical physics 146(21), 211103 (2017) [10.1063/1.4984774]   We prove the hitherto hypothesized sequential dissociation of Fe(CO)$_5$ in the gas phase upon photoexcitation at 266 nm via a singlet pathway with time-resolved valence and core-level photoelectron spectroscopy with an x-ray free-electron laser. Valence photoelectron spectra are used to identify free CO molecules and to determine the time constants of stepwise dissociation to Fe(CO)$_4$ within the temporal resolution of the experiment and further to Fe(CO)$_3$ within 3 ps [...] OpenAccess: PDF PDF (PDFA); 2017-05-0415:03 [PUBDB-2017-02270] Journal Article et al Catalysis in real time using X-ray lasers Chemical physics letters 675, 145 - 173 (2017) [10.1016/j.cplett.2017.02.018]   We describe how the unique temporal and spectral characteristics of X-ray free-electron lasers (XFEL) can be utilized to follow chemical transformations in heterogeneous catalysis in real time. We highlight the systematic study of CO oxidation on Ru(0 0 0 1), which we initiate either using a femtosecond pulse from an optical laser or by activating only the oxygen atoms using a THz pulse [...] OpenAccess: PDF; 2017-02-2210:40 [PUBDB-2017-01078] Journal Article et al First Operation of a Harmonic Lasing Self-Seeded Free Electron Laser   Harmonic lasing is a possible mode of operation of X-ray FEL user facilities that allows us to provide brilliant beams of higher energy photons for user experiments. Another useful application of harmonic lasing is the so-called harmonic lasing self-seeded free electron laser (HLSS FEL) that allows the improvement of spectral brightness of these facilities. [...] OpenAccess: PDF; Restricted: PDF; External link: Fulltext 2016-12-1209:36 [PUBDB-2016-06076] Journal Article et al Anti-Stokes resonant x-ray Raman scattering for atom specific and excited state selective dynamics New journal of physics 18(10), 103011 (2016) [10.1088/1367-2630/18/10/103011]   Ultrafast electronic and structural dynamics of matter govern rate and selectivity of chemical reactions, as well as phase transitions and efficient switching in functional materials. Since x-rays determine electronic and structural properties with elemental, chemical, orbital and magnetic selectivity, short pulse x-ray sources have become central enablers of ultrafast science. [...] OpenAccess: PDF PDF (PDFA); 2016-12-0514:21 [PUBDB-2016-05879] Journal Article et al Chemical Bond Activation Observed with an X-ray Laser The journal of physical chemistry letters 7(18), 3647 - 3651 (2016) [10.1021/acs.jpclett.6b01543]   The concept of bonding and antibonding orbitals is fundamental in chemistry. The population of those orbitals and the energetic difference between the two reflect the strength of the bonding interaction. [...] Published on 2016-09-01. Available in OpenAccess from 2017-09-01.: PDF; 2016-11-1014:14 [PUBDB-2016-04896] Journal Article et al Orbital-specific mapping of the ligand exchange dynamics of $Fe(CO)_{5}$ in solution Nature 520(7545), 78 - 81 (2015) [10.1038/nature14296]   Transition-metal complexes have long attracted interest for fundamental chemical reactivity studies and possible use in solar energy conversion1, 2. Electronic excitation, ligand loss from the metal centre, or a combination of both, creates changes in charge and spin density at the metal site3, 4, 5, 6, 7, 8, 9, 10, 11 that need to be controlled to optimize complexes for photocatalytic hydrogen production8 and selective carbon–hydrogen bond activation9, 10, 11. [...] Published on 2015-04-01. Available in OpenAccess from 2015-10-01.: PDF; Restricted: PDF PDF (PDFA); 2016-11-1012:12 [PUBDB-2016-04869] Journal Article et al Identification of the dominant photochemical pathways and mechanistic insights to the ultrafast ligand exchange of Fe(CO)$_{5}$ to Fe(CO)$_{4}$EtOH Structural dynamics 3(4), 043204 (2016) [10.1063/1.4941602]   We utilized femtosecond time-resolved resonant inelastic X-ray scattering and ab initio theory to study the transient electronic structure and the photoinduced molecular dynamics of a model metal carbonyl photocatalyst Fe(CO)$_5$ in ethanol solution. We propose mechanistic explanation for the parallel ultrafast intra-molecular spin crossover and ligation of the Fe(CO)$_4$ which are observed following a charge transfer photoexcitation of Fe(CO)$_5$ as reported in our previous study [Wernet et al., Nature 520, 78 (2015)]. [...] OpenAccess: PDF PDF (PDFA); 2016-11-1010:20 [PUBDB-2016-04837] Journal Article et al Role of heat accumulation in the multi-shot damage of silicon irradiated with femtosecond XUV pulses at a 1 MHz repetition rate Optics express 24(14), 15468 - 15477 (2016) [10.1364/OE.24.015468]   The role played by heat accumulation in multi-shot damage of silicon was studied. Bulk silicon samples were exposed to intense XUV monochromatic radiation of a 13.5 nm wavelength in a series of 400 femtosecond pulses, repeated with a 1 MHz rate (pulse trains) at the FLASH facility in Hamburg. [...] OpenAccess: PDF PDF (PDFA);