# FS-FLASH-O

 2019-02-2017:27 [PUBDB-2019-01185] Journal Article et al Terahertz-Field-Induced Time Shifts in Atomic Photoemission Physical review letters 122(7), 073001 (2019) [10.1103/PhysRevLett.122.073001]   Time delays for atomic photoemission obtained in streaking or reconstruction of attosecond bursts by interference of two-photon transitions experiments originate from a combination of the quantum mechanical Wigner time and the Coulomb-laser coupling. While the former was investigated intensively theoretically as well as experimentally, the latter attracted less interest in experiments and has mostly been subject to calculations [...] OpenAccess: PDF PDF (PDFA); 2019-01-2811:43 [PUBDB-2019-00765] Journal Article et al Hindered nematic alignment of hematite spindles in poly( N-isopropylacrylamide) hydrogels: a small-angle X-ray scattering and rheology study Journal of applied crystallography 51(1), 87 - 96 (2018) [10.1107/S1600576717017411]   Field-induced changes to the mesostructure of ferrogels consisting of spindle-shaped hematite particles and poly(N-isopropylacrylamide) are investigated by means of small-angle X-ray scattering (SAXS). Related field-induced changes to the macroscopic viscoelastic properties of these composites are probed by means of oscillatory shear experiments in an external magnetic field. [...] Restricted: PDF PDF (PDFA); 2019-01-0810:16 [PUBDB-2019-00093] Journal Article et al Symmetry breakdown of electron emission in extreme ultraviolet photoionization of argon Nature Communications 9(1), 4659 (2018) [10.1038/s41467-018-07152-7]   Short wavelength free-electron lasers (FELs), providing pulses of ultrahigh photon intensity, have revolutionized spectroscopy on ionic targets. Their exceptional photon flux enables multiple photon absorptions within a single femtosecond pulse, which in turn allows for deep insights into the photoionization process itself as well as into evolving ionic states of a target [...] OpenAccess: PDF PDF (PDFA); 2019-01-0809:36 [PUBDB-2019-00089] Journal Article et al Auger electron angular distributions following excitation or ionization of the I 3d level in methyl iodide The journal of chemical physics 149(9), 094304 (2018) [10.1063/1.5045640]   Auger electron spectra following excitation or ionization of the I 3d level in CH$_3$I have been recorded with horizontally or vertically plane polarized synchrotron radiation. These spectra have enabled the Auger electron angular distributions, as characterized by the β parameter, to be determined. [...] Published on 2018-09-06. Available in OpenAccess from 2019-09-06.: PDF PDF (PDFA); 2019-01-0809:34 [PUBDB-2019-00088] Journal Article et al Photoionization of the iodine 3d, 4s, and 4p orbitals in methyl iodide The journal of chemical physics 149(14), 144302 (2018) [10.1063/1.5035496]   Ionization of the I 3d, 4s, and 4p orbitals in methyl iodide (CH$_3$I) has been studied by using synchrotron radiation to measure the total ion yield and by recording photoelectron spectra with linearly polarized radiation in two polarization orientations. The complete photoelectron spectrum of CH3I has been recorded at several photon energies, and bands due to the C 1s, I 3d, 4s, 4p, and 4d atomic-like orbitals, as well as the molecular orbitals, have been observed and assigned. [...] Published on 2018-10-08. Available in OpenAccess from 2019-10-08.: PDF PDF (PDFA); 2018-12-0120:24 [PUBDB-2018-05141] Journal Article et al Coulomb explosion imaging of $CH_{3}I$ and $C_{2}ClI$ photodissociation dynamics The journal of chemical physics 149(20), 204313 (2018) [10.1063/1.5041381]   The photodissociation dynamics of CH$_3$I and CH$_2$ClI at 272 nm were investigated by time-resolved Coulomb explosion imaging, with an intense non-resonant 815 nm probe pulse. Fragment ion momenta over a wide m/z range were recorded simultaneously by coupling a velocity map imaging spectrometer with a pixel imaging mass spectrometry camera. [...] Published on 2018-11-30. Available in OpenAccess from 2019-11-30.: PDF PDF (PDFA); 2018-11-2816:30 [PUBDB-2018-04936] Poster et al Status of the Superconducting Soft X-ray Free-Electron Laser FLASH at DESY 9th International Particle Accelerator Conference, IPAC'18, VancouverVancouver, Canada, 29 Apr 2018 - 4 May 2018   FLASH, the free-electron laser (FEL) user facility at DESY, deliverers high brilliance XUV and soft x-ray FEL radiation for photon experiments since summer 2005.In 2014 and 2015 a second beamline, FLASH2, has been commissioned in parallel to user operation at FLASH1.FLASH's superconducting linac can produce bunch trains of up to 800 bunches within a 0.8 ms RF flat top at a repetition rate of 10 Hz.In standard operation during 2017 FLASH supplied up to 500 bunches in two bunch trains with independent fill patterns and compression schemes.Since mid 2017 initial commissioning of a third experimental beamline, accommodating the FLASHForward plasma wakefield acceleration experiment, has started.We report on the highlights of the FLASH operation in 2017/2018.. OpenAccess: PDF PDF (PDFA); 2018-11-2816:23 [PUBDB-2018-04935] Contribution to a conference proceedings et al Status of the Superconducting Soft X-ray Free-Electron Laser FLASH at DESY 9th International Particle Accelerator Conference, IPAC'18, VancouverVancouver, Canada, 29 Apr 2018 - 4 May 2018 4 pp. (2018) [10.3204/PUBDB-2018-04935]   FLASH, the free-electron laser (FEL) user facility at DESY, deliverers high brilliance XUV and soft x-ray FEL radiation for photon experiments since summer 2005.In 2014 and 2015 a second beamline, FLASH2, has been commissioned in parallel to user operation at FLASH1.FLASH's superconducting linac can produce bunch trains of up to 800 bunches within a 0.8 ms RF flat top at a repetition rate of 10 Hz.In standard operation during 2017 FLASH supplied up to 500 bunches in two bunch trains with independent fill patterns and compression schemes.Since mid 2017 initial commissioning of a third experimental beamline, accommodating the FLASHForward plasma wakefield acceleration experiment, has started.We report on the highlights of the FLASH operation in 2017/2018.. OpenAccess: PDF PDF (PDFA); External link: Fulltext 2018-11-1316:52 [PUBDB-2018-04481] Journal Article et al Damage accumulation in thin ruthenium films induced by repetitive exposure to femtosecond XUV pulses below the single-shot ablation threshold Journal of the Optical Society of America / B 35(11), 2799 - 2805 (2018) [10.1364/JOSAB.35.002799]   The process of damage accumulation in thin ruthenium films exposed to multiple femtosecond extreme ultraviolet (XUV) free-electron laser (FEL) pulses below the critical angle of reflectance at the FEL facility in Hamburg (FLASH) was experimentally analyzed. The multi-shot damage threshold is found to be lower than the single-shot damage threshold. [...] Restricted: PDF PDF (PDFA); 2018-11-0116:28 [PUBDB-2018-04108] Journal Article et al Double-grating monochromatic beamline with ultrafast response for FLASH2 at DESY Journal of synchrotron radiation 25(1), 131 - 137 (2018) [10.1107/S1600577517013777]   The preliminary design of a monochromatic beamline for FLASH2 at DESY is presented. The monochromator is tunable in the 50–1000 eV energy range with resolving power higher than 1000 and temporal response below 50 fs over the whole energy range [...] OpenAccess: PDF PDF (PDFA);