# FS-FLASH-D

 2019-07-0916:35 [PUBDB-2019-02676] Journal Article et al Electronic decay of core-excited HCl molecules probed by THz streaking Structural dynamics 6(3), 034301 (2019) [10.1063/1.5091756]   The ultrafast electronic decay of HCl molecules in the time domain after resonant core excitation was measured. Here, a Cl-2p core electron was promoted to the antibonding σ* orbital initiating molecular dissociation, and simultaneously, the electronic excitation relaxes via an Auger decay [...] OpenAccess: PDF PDF (PDFA); 2019-06-2110:30 [PUBDB-2019-02527] Journal Article et al Two-color XUV+NIR femtosecond photoionization of neon in the near-threshold region New journal of physics 21(6), 063034 (2019) [10.1088/1367-2630/ab2a98]   Results of angle-resolved electron spectroscopy of near-threshold photoionization of Ne atoms bycombined femtosecond extreme ultraviolet and near infraredfields are presented. The dressed-electron spectra show an energetic distribution into so-called sidebands, being separated by thephoton energy of the dressing laser [...] OpenAccess: PDF PDF (PDFA); 2019-05-2911:54 [PUBDB-2019-02388] Journal Article et al An X-ray gas monitor for free-electron lasers Journal of synchrotron radiation 26(4), 1092 - 1100 (2019) [10.1107/S1600577519005174]   A novel X-ray gas monitor (XGM) has been developed which allows the measurement of absolute photon pulse energy and photon beam position at all existing and upcoming free-electron lasers (FELs) over a broad spectral range covering vacuum ultraviolet (VUV), extreme ultraviolet (EUV) and soft and hard X-rays. The XGM covers a wide dynamic range from spontaneous undulator radiation to FEL radiation and provides a temporal resolution of better than 200 ns [...] OpenAccess: PDF PDF (PDFA); 2019-01-0810:09 [PUBDB-2019-00091] Journal Article et al SwissFEL Aramis beamline photon diagnostics Journal of synchrotron radiation 25(4), 1238 - 1248 (2018) [10.1107/S1600577518005775]   The SwissFEL Aramis beamline, covering the photon energies between 1.77 keV and 12.7 keV, features a suite of online photon diagnostics tools to help both users and FEL operators in analysing data and optimizing experimental and beamline performance. Scientists will be able to obtain information about the flux, spectrum, position, pulse length, and arrival time jitter versus the experimental laser for every photon pulse, with further information about beam shape and size available through the use of destructive screens [...] OpenAccess: PDF PDF (PDFA); 2019-01-0715:26 [PUBDB-2019-00062] Journal Article et al Femtosecond profiling of shaped x-ray pulses New journal of physics 20(3), 033008 (2018) [10.1088/1367-2630/aab548]   Arbitrary manipulation of the temporal and spectral properties of x-ray pulses at free-electron lasers would revolutionize many experimental applications. At the Linac Coherent Light Source at Stanford National Accelerator Laboratory, the momentum phase-space of the free-electron laser driving electron bunch can be tuned to emit a pair of x-ray pulses with independently variable photon energy and femtosecond delay [...] OpenAccess: PDF PDF (PDFA); 2018-11-2715:49 [PUBDB-2018-04884] Journal Article et al Separating Dipole and Quadrupole Contributions to Single-Photon Double Ionization Physical review letters 121(17), 173003 (2018) [10.1103/PhysRevLett.121.173003]   We report on a kinematically complete measurement of double ionization of helium by a single 1100 eV circularly polarized photon. By exploiting dipole selection rules in the two-electron continuum state, we observed the angular emission pattern of electrons originating from a pure quadrupole transition [...] OpenAccess: PDF PDF (PDFA); 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); 2018-11-0716:12 [PUBDB-2018-04297] Conference Presentation et al Towards Chirp Control of XUV Free Electron Lasers 8th EPS-QEOD EUROPHOTON CONFERENCE, BarcelonaBarcelona, Spain, 2 Sep 2018 - 7 Sep 2018   We use 267nm femtosecond laser pulses to modulate electrons of a XUV free electron laser. By changing the chirp of this laser pulses we can influence the chirp of the generated XUV FEL pulses, which are characterized by THz streaking. [...] OpenAccess: Summary_Europhoton2018_MK20042018 - PDF PDF (PDFA); Towards Chirp Control of XUV Free Electron Lasers_MK_PUBDB - PPTX; 2018-11-0115:53 [PUBDB-2018-04105] Journal Article et al Time-resolved electron spectroscopy for chemical analysis of photodissociation: Photoelectron spectra of Fe(CO)$_5$ , Fe(CO)$_4$ , and Fe(CO)$_3$ The journal of chemical physics 149(4), 044307 (2018) [10.1063/1.5035149]   The prototypical photoinduced dissociation of Fe(CO)$_5$ in the gas phase is used to test time-resolved x-ray photoelectron spectroscopy for studying photochemical reactions. Upon one-photon excitation at 266 nm, Fe(CO)$_5$ successively dissociates to Fe(CO)$_4$ and Fe(CO)$_3$ along a pathway where both fragments retain the singlet multiplicity of Fe(CO)$_5$. [...] Published on 2018-07-27. Available in OpenAccess from 2019-07-27.: PDF PDF (PDFA); 2018-10-1414:42 [PUBDB-2018-03783] Journal Article et al Photoionization of metastable heliumlike $C^{4+}$($1s\,2s\; ^3S_ 1)$ ions: Precision study of intermediate doubly excited states Physical review / A 98(3), 033416 (2018) [10.1103/PhysRevA.98.033416]   In a joint experimental and theoretical endeavor, photoionization of metastable $C^{4+}$($1s\,2s\; ^3S_ 1)$ ions via intermediate levels with hollow, double-K-vacancy configurations $2s2p, 2s3p, 2p3s, 2p3d, 2s4p, 2p4s$, and $2p4d$ has been investigated. High-resolution photon-ion merged-beams measurements were carried out with the resolving power reaching up to 25 800 which is sufficient to separate the leading fine-structure components of the $2s2p^{3}P$ term. [...] OpenAccess: PDF PDF (PDFA);