FS-PS

 2019-06-0321:21 [PUBDB-2019-02410] Journal Article et al Photoionization and photofragmentation of singly charged positive and negative Sc$_3$N@C$_{80}$ endohedral fullerene ions Physical review / A 99(6), 063401 (2019) [10.1103/PhysRevA.99.063401]   Photoprocesses of the endohedral fullerene ions Sc$_3$N@C$_{80}^+$ and Sc$_3$N@C$_{80}^-$ in the gas phase have been investigated in the photon energy ranges 30--50 eV and 280--420 eV. Single and double ionization as well as single ionization accompanied by the release of a C$_2$ dimer were observed as a function of the photon energy for the positive parent ion and double detachment was measured for the negative parent ion. [...] OpenAccess: PDF PDF (PDFA); External link: Fulltext 2019-05-2607:50 [PUBDB-2019-02368] Journal Article et al The photon‐ion merged‐beams experiment PIPE at PETRA III—The first five years X-ray spectrometry XXX, xrs.3035 (2019) [10.1002/xrs.3035]   The Photon-Ion Spectrometer at PETRAIII—in short, PIPE—is a permanentlyinstalled user facility at the "Variable Polarization XUV Beamline" P04 of thesynchrotron light source PETRA III operated by DESY in Hamburg, Germany.The careful design of the PIPE ion-optics in combination with the record-highphoton flux at P04 has lead to a breakthrough in experimental studies ofphoton interactions with ionized small quantum systems. This short reviewprovides an overview over the published scientific results from photon-ionmerged-beams experiments at PIPE that were obtained since the start of P04operations in 2013. [...] Restricted: PDF PDF (PDFA); External link: Fulltext 2019-04-2514:46 [PUBDB-2019-02076] Journal Article et al Spaping femtosecond laser pulses at short wavelength with grazing-incidence optics Optics express 27(9), 13479 - 13491 (2019) [10.1364/OE.27.013479]   We present the design of an extreme ultraviolet (XUV) pulse shaper relying on reflective optics. The instrument will allow tailoring of the time-frequency spectrum of femtosecond pulses generated by seeded free-electron lasers (FEL) and high-harmonic generation (HHG) sources down to a central wavelength of ~15 nm [...] OpenAccess: PDF PDF (PDFA); 2019-04-1013:33 [PUBDB-2019-01921] Journal Article et al Simultaneous Observation of the Er- and Fe-Sublattice Magnetization of Ferrimagnetic $Er_{3}Fe_{5}O_{12}$ in High Magnetic Fields Using X-Ray Magnetic Circular Dichroism at the Er $L_{2 ,3}$ Edges Physical review letters 122(12), 127204 (2019) [10.1103/PhysRevLett.122.127204]   X-ray magnetic circular dichroism (XMCD) studies at the Er $L_{2 ,3}$ edges of $Er_{3}Fe_{5}O_{12}$ exhibit a change of the spectral shape as a function of temperature and magnetic field. Using singular value decomposition, this variation is understood as a linear combination of two components [...] Restricted: PDF PDF (PDFA); 2019-04-1013:30 [PUBDB-2019-01920] Journal Article et al Microscopic Nature of the First-Order Field-Induced Phase Transition in the Strongly Anisotropic Ferrimagnet $HoFe_{5}Al_{7}$ Physical review letters 122(12), 127205 (2019) [10.1103/PhysRevLett.122.127205]   We report on x-ray magnetic circular dichroism experiments in pulsed fields up to 30 T to follow the rotations of individual magnetic moments through the field-induced phase transition in the ferrimagnet $HoFe_{5}Al_{7}$. Near the ground state, we observe simultaneous stepwise rotations of the Ho and Fe moments and explain them using a two-sublattice model for an anisotropic ferrimagnet with weak intersublattice exchange interactions [...] OpenAccess: PDF PDF (PDFA); 2019-04-1013:20 [PUBDB-2019-01919] Journal Article et al Light Source Upgrades at DESY: PETRA IV and FLASH2020+ Synchrotron radiation news 32(1), 27 - 31 (2019) [10.1080/08940886.2019.1559605]   Restricted: PDF PDF (PDFA); 2019-04-0910:50 [PUBDB-2019-01910] Preprint/Report et al Scientific Opportunities with an X-ray Free-Electron Laser Oscillator [arXiv:1903.09317]   An X-ray free-electron laser oscillator (XFELO) is a new type of hard X-ray source that would produce fully coherent pulses with meV bandwidth and stable intensity. The XFELO complements existing sources based on self-amplified spontaneous emission (SASE) from high-gain X-ray free-electron lasers (XFEL) that produce ultra-short pulses with broad-band chaotic spectra [...] OpenAccess: PDF PDF (PDFA); 2019-04-0113:07 [PUBDB-2019-01790] Journal Article et al Spectral Control of an X-Ray L -Edge Transition via a Thin-Film Cavity Physical review letters 122(12), 123608 (2019) [10.1103/PhysRevLett.122.123608]   By embedding a thin layer of tantalum in an x-ray cavity, we observe a change in the spectral characteristics of an inner-shell transition of the metal. The interaction between the cavity mode vacuum and the $L_{III}$-edge transition is enhanced, permitting the observation of the collective Lamb shift, superradiance, and a Fano-like cavity-resonance interference effect [...] OpenAccess: PDF PDF (PDFA); 2019-03-0414:40 [PUBDB-2019-01320] Journal Article et al Nuclear resonant scattering from $^{193}Ir$ as a probe of the electronic and magnetic properties of iridates Scientific reports 9(1), 5097 (2019) [10.1038/s41598-019-41130-3]   The high brilliance of modern synchrotron radiation sources facilitates experiments with high-energy x-rays across a range of disciplines, including the study of the electronic and magnetic correlations using elastic and inelastic scattering techniques. Here we report on Nuclear Resonance Scattering at the 73 keV nuclear level in $^{193}$Ir [...] OpenAccess: PDF PDF (PDFA); 2019-02-2213:12 [PUBDB-2019-01222] Journal Article et al Superradiance of an ensemble of nuclei excited by a free electron laser Nature physics 14(3), 261 - 264 (2018) [10.1038/s41567-017-0001-z]   In 1954 Dicke predicted the accelerated initial decay of multiple atomic excitations1, laying the foundation for the concept of superradiance. Further studies$^{2,3,4}$ suggested that emission of the total energy was similarly accelerated, provided that the system reaches the inversion threshold. [...] Restricted: PDF PDF (PDFA);