# FS-CFEL-3

 2018-12-0509:40 [PUBDB-2018-05211] Journal Article et al Ultrafast nuclear dynamics in the doubly-core-ionized water molecule observed via Auger spectroscopy Physical review / A 98(6), 063403 (2018) [10.1103/PhysRevA.98.063403]   We present a combined experimental and theoretical study of the Auger-emission spectrum following double core ionization and excitation of gas-phase water molecules with hard-x-ray synchrotron radiation above the O $K^{−2}$ threshold. We observe an indication of ultrafast proton motion occurring within the 1.5 fs lifetime of the double-core-hole (DCH) states in water [...] OpenAccess: PDF PDF (PDFA); 2018-12-0509:31 [PUBDB-2018-05209] Journal Article Santra, R. Theory of x-ray scattering from laser-driven electronic systems Physical review / B 98(22), 224302 (2018) [10.1103/PhysRevB.98.224302]   We describe, within the framework of quantum electrodynamics, an interaction between a nonresonant hard x-ray pulse and an electronic system in the presence of a temporally periodic laser field driving electron dynamics in this system. We apply Floquet theory to describe the laser-driven electronic system, and then obtain the scattering probability of an arbitrary nonresonant x-ray pulse from such a system employing the density-matrix formalism [...] OpenAccess: PDF PDF (PDFA); 2018-10-1710:44 [PUBDB-2018-03818] Poster et al Ultrafast Demagnetization by Extreme Ultraviolet Light German Conference for Research with Synchrotron Radiation, Neutrons and Ion Beams at Large Facilities, SNI, MünchenMünchen, Germany, 17 Sep 2018 - 19 Sep 2018 Free-electron lasers (FELs) enable the study of dynamics in matter on combined femtosecond time and nanometer length scales [1]. One of the most intriguing topics within contemporary research on magnetism, ultrafast near-infrared (IR) laser-induced demagnetization [2,3], has greatly benefited from the advent of FELs [4] as it was shown that optically generated superdiffusive spin currents [5] contribute to that phenomenon [6]. [...] 2018-10-1109:55 [PUBDB-2018-03750] Journal Article et al Relativistic and resonant effects in the ionization of heavy atoms by ultra-intense hard X-rays Nature Communications 9(1), 4200 (2018) [10.1038/s41467-018-06745-6]   An accurate description of the interaction of intense hard X-ray pulses with heavy atoms,which is crucial for many applications of free-electron lasers, represents a hitherto unresolvedchallenge for theory because of the enormous number of electronic configurations andrelativistic effects, which need to be taken into account. Here we report results on multipleionization of xenon atoms by ultra-intense (about 1019W/cm2) femtosecond X-ray pulses atphoton energies from 5.5 to 8.3 keV and present a theoretical model capable of reproducingthe experimental data in the entire energy range. [...] OpenAccess: PDF PDF (PDFA); 2018-09-2812:02 [PUBDB-2018-03674] Journal Article Welsch, R. Low-Temperature Thermal Rate Constants for the Water Formation Reaction $\mathrm{H_{2}}+OH$ from Rigorous Quantum Dynamics Calculations Angewandte Chemie / International edition 57(40), 13150 - 13153 (2018) [10.1002/anie.201807666]   Thermal rate constants for the prototypical water‐forming reaction $\mathrm{H_{2}}+OH \to H+H_{2}O$ were obtained for temperatures between 150 K and 600 K by rigorous quantum dynamics calculations including all degrees of freedom. Results are reported for a recent, highly accurate neural network potential (NN1) and compared to results obtained on a previous, semi‐empirical potential (SE) [...] Restricted: PDF PDF (PDFA); 2018-09-2811:58 [PUBDB-2018-03673] Journal Article et al Modeling of XUV-induced damage in Ru films: the role of model parameters Journal of the Optical Society of America / B 35(10), B43 - B53 (2018) [10.1364/JOSAB.35.000B43]   We perform a computational study of damage formation in extreme ultraviolet (XUV)-irradiated ruthenium thin films by means of combining the Monte Carlo approach with the two-temperature model. The model predicts that the damage formation is most affected by ultrafast heating of the lattice by hot electrons, and is not very sensitive to the initial stage of the material excitation [...] OpenAccess: PDF PDF (PDFA); 2018-09-2811:53 [PUBDB-2018-03672] Journal Article et al Mechanism of single-shot damage of Ru thin films irradiated by femtosecond extreme UV free-electron laser Optics express 26(15), 19665 - 19685 (2018) [10.1364/OE.26.019665]   Ruthenium is a perspective material to be used for XUV mirrors at free-electron laser facilities. Yet, it is still poorly studied in the context of ultrafast laser-matter interaction. [...] OpenAccess: PDF PDF (PDFA); 2018-09-2513:35 [PUBDB-2018-03578] Journal Article et al Towards the theoretical limitations of X-ray nanocrystallography at high intensity: the validity of the effective-form-factor description IUCrJ 5(6), 699 - 705 (2018) [10.1107/S2052252518011442]   X-ray free-electron lasers (XFELs) broaden horizons in X-ray crystallography. Facilitated by the unprecedented high intensity and ultrashort duration of the XFEL pulses, they enable us to investigate the structure and dynamics of macromolecules with nano-sized crystals [...] OpenAccess: PDF PDF (PDFA); 2018-09-1712:23 [PUBDB-2018-03517] Journal Article et al Hard X-ray induced fast secondary electron cascading processes in solids Applied physics letters 113(11), 114102 (2018) [10.1063/1.5046070]   Recent studies confirmed that the materials used in the extreme UV and soft X-ray regime for precise characterization of intense free-electron laser pulses (e.g., Si$_3$N$_4$) do not work efficiently in the hard X-ray regime, which is due to the fact that the impact of a hard X-ray photon is followed by a series of electron cascading processes. Following theoretical indication, we show that this limitation can be circumvented and the cascading time can be significantly reduced if the X-ray photon energy is double the ionization energy. [...] Published on 2018-09-14. Available in OpenAccess from 2019-09-14.: PDF PDF (PDFA); 2018-08-2709:42 [PUBDB-2018-03176] Journal Article et al Various damage mechanisms in carbon and silicon materials under femtosecond X-ray irradiation 4Open 1, 3 (2018) [10.1051/fopen/2018003]   We review the results of our research on damage mechanisms in materials irradiated with femtosecond free-electron-laser (FEL) pulses. They were obtained using our hybrid approach, X-ray-induced thermal and non-thermal transitions (XTANT) [...] OpenAccess: PDF PDF (PDFA);