A5008947213- Advanced X-ray Imaging Techniques
- Advanced Electron Microscopy Techniques and Applications
- Magnetism in coordination complexes
- X-ray Spectroscopy and Fluorescence Analysis
- Hemoglobin structure and function
- Spectroscopy and Quantum Chemical Studies
- Particle Accelerators and Free-Electron Lasers
- Electron Spin Resonance Studies
- Photosynthetic Processes and Mechanisms
- Enzyme Structure and Function
- Photoreceptor and optogenetics research
- Photochemistry and Electron Transfer Studies
- Lanthanide and Transition Metal Complexes
- Laser-Matter Interactions and Applications
- Advanced Chemical Physics Studies
- Protein Structure and Dynamics
- Crystallography and Radiation Phenomena
- Diamond and Carbon-based Materials Research
- Electron and X-Ray Spectroscopy Techniques
- Porphyrin and Phthalocyanine Chemistry
- High-pressure geophysics and materials
- Laser-Plasma Interactions and Diagnostics
- Organic and Molecular Conductors Research
- Mass Spectrometry Techniques and Applications
- X-ray Diffraction in Crystallography
European Synchrotron Radiation Facility
2009-2025
Institut de Physique de Rennes
2015-2024
Centre National de la Recherche Scientifique
2013-2024
Université de Rennes
2013-2024
European Science Foundation
2009-2024
Elkhorn Slough Foundation
2011-2023
SLAC National Accelerator Laboratory
2010-2020
Lawrence Livermore National Laboratory
2020
Institut de minéralogie, de physique des matériaux et de cosmochimie
2020
University of Göttingen
2018
The X-ray Pump-Probe instrument achieves femtosecond time-resolution with hard methods using a free-electron laser source. It covers photon energy range of 4-24 keV. A optical system is available across broad spectrum wavelengths for generating transient states matter. designed to emphasize versatility and the scientific goals encompass ultrafast physical, chemical biological processes involved in transformation matter transfer at atomic scale.
Abstract Light absorption can trigger biologically relevant protein conformational changes. The light-induced structural rearrangement at the level of a photoexcited chromophore is known to occur in femtosecond timescale and expected propagate through as quake-like intramolecular motion. Here we report direct experimental evidence such ‘proteinquake’ observed myoglobin X-ray solution scattering measurements performed Linac Coherent Source free-electron laser. An ultrafast increase radius...
The description of ultrafast nonadiabatic chemical dynamics during molecular photo-transformations remains challenging because electronic and nuclear configurations impact each other cannot be treated independently. Here we gain experimental insights, beyond the Born-Oppenheimer approximation, into light-induced spin-state trapping prototypical [Fe(bpy)
Light makes light work of fatty acids Photosynthetic organisms are notable for their ability to capture energy and use it power biosynthesis. Some algae have gone a step beyond photosynthesis can initiate enzymatic photodecarboxylation acids, producing long-chain hydrocarbons. To understand this transformation, Sorigué et al. brought bear an array structural, computational, spectroscopic techniques fully characterized the catalytic cycle enzyme. These experiments consistent with mechanism...
Abstract High-intensity femtosecond pulses from an X-ray free-electron laser enable pump–probe experiments for the investigation of electronic and nuclear changes during light-induced reactions. On timescales ranging femtoseconds to milliseconds a variety biological systems, time-resolved serial crystallography (TR-SFX) has provided detailed structural data isomerization, breakage or formation chemical bonds electron transfer 1,2 . However, all ultrafast TR-SFX studies date have employed...
We report direct structural evidence of the bridged radical (CH 2 ICH ·) in a polar solution, obtained using time-resolved liquid-phase x-ray diffraction. This transient intermediate has long been hypothesized to explain stereo-chemical control many association and/or dissociation reactions involving haloalkanes. Ultrashort optical pulses were used dissociate an iodine atom from haloethane molecule (C H 4 I ) dissolved methanol, and diffraction picosecond synchrotron supports following...
X-ray free electron lasers (XFELs) deliver short (<100 fs) and intense (∼10(12) photons) pulses of hard X-rays, making them excellent sources for time-resolved studies. Here we show that, despite the inherent instabilities current (SASE based) XFELs, they can be used measuring high-quality absorption data report femtosecond near-edge spectroscopy (XANES) measurements a spin-crossover system, iron(II) tris(2,2'-bipyridine) in water. The indicate that low-spin to high-spin transition modeled...
We show that light drives large-amplitude structural changes in thin films of the prototypical ferroelectric ${\mathrm{PbTiO}}_{3}$ via direct coupling to its intrinsic photovoltaic response. Using time-resolved x-ray scattering visualize atomic displacements on femtosecond time scales, photoinduced unit-cell tetragonality are observed. These driven by motion photogenerated free charges within and can be simply explained a model including both shift screening currents, associated with...
We report hard x-ray single-shot spectral measurements of the Linac Coherent Light Source. The spectrometer is based on a 10 μm thick cylindrically bent Si single crystal operating in symmetric Bragg geometry to provide dispersion and high transmission simultaneously. It covers range &gt;1% using Si(111) reflection. Using Si(333) reflection, it reaches resolving power better than 42 000 transmits &gt;83% incident flux at 8.3 keV. resolution enabled observation individual spikes...
A growing number of X-ray sources based on the free-electron laser (XFEL) principle are presently under construction or have recently started operation. The intense, ultrashort pulses these will enable new insights in many different fields science. key problem is to provide x-ray optical elements capable collecting largest possible fraction radiation and focus into smallest focus. As a step towards this goal, we demonstrate here first nanofocusing hard XFEL pulses. We developed diamond...
A chopper system for time resolved pump-probe experiments with x-ray beams from a synchrotron is described. The has three parts: water-cooled heatload chopper, high-speed and millisecond shutter. system, which installed in beamline ID09B at the European Synchrotron Radiation Facility, provides short pulses ultrafast lasers. can produce as 200 ns continuous beam repeat frequencies 0 to 3 kHz. For bunch filling patterns of pulse separations greater than 100 ns, isolate single ps that are used...
Abstract Phytochromes are photoreceptor proteins that transmit a light signal from photosensory region to an output domain. Photoconversion involves protein conformational changes whose nature is not fully understood. Here, we use time-resolved X-ray scattering and optical spectroscopy study the kinetics of structural in full-length cyanobacterial phytochrome truncated form with no spectroscopic signals on µs/ms timescale largely independent presence On longer time-scales, large differences...
We present a new technique for measuring the relative delay between soft x-ray FEL pulse and an optical laser that indicates sub 25 fs RMS measurement error. An ultra-short photo-ionizes semiconductor (Si(3)N(4)) membrane changes transmission. continuum with temporally chirped bandwidth spanning 630 nm-710 nm interacts such timing of can be determined from onset spectral modulation transmitted pulse. This experiment demonstrates nearly in situ single-shot arrival time to
We study the basic mechanisms allowing light to photoswitch at molecular scale a spin-crossover material from low- high-spin state. Combined femtosecond x-ray absorption performed LCLS X-FEL and optical spectroscopy reveal that structural stabilization of photoinduced state results two step trapping. Molecular breathing vibrations are first activated rapidly damped as part energy is sequentially transferred bending vibrations. During photoswitching, system follows curved trajectory on...
We measured the transverse and longitudinal coherence properties of Linac Coherent Light Source (LCLS) at SLAC in hard x-ray regime 9 keV photon energy on a single shot basis. Speckle patterns recorded forward direction from colloidal nanoparticles yielded focused LCLS beam. gold nanopowder with atomic resolution allowed us to measure shot-to-shot variations spectral The beam is fully coherent mode number close 1. average modes behind Si(111) monochromator about 14.5 time τ(c)=(2.0±1.0) fc....
The availability of ultrafast pulses coherent hard x-rays from the Linac Coherent Light Source opens new opportunities for studies atomic-scale dynamics in amorphous materials. Here we show that single x-ray can be used to observe speckle contrast high-angle diffraction liquid Ga and glassy Ni2Pd2P B2O3. We determine thresholds above which disturb atomic arrangements. Furthermore, high is observed scattering patterns glasses integrated over many pulses, demonstrating source optics are...
Abstract X-ray free-electron lasers (XFELs) enable novel experiments because of their high peak brilliance and femtosecond pulse duration. However, non-superconducting XFELs offer repetition rates only 10–120 Hz, placing significant demands on beam time sample consumption. We describe serial crystallography performed at the European XFEL, first MHz rate delivering 1.128 trains 10 Hz. Given short spacing between pulses, damage caused by shock waves launched one XFEL probed subsequent pulses...
In liquid phase chemistry dynamic solute-solvent interactions often govern the path, ultimate outcome, and efficiency of chemical reactions. These steps involve many-body movements on subpicosecond time scales thus ultrafast structural tools capable capturing both intramolecular electronic changes, local solvent changes are desired. We have studied intra- intermolecular dynamics a model chromophore, aqueous [Fe(bpy)3](2+), with complementary X-ray in single experiment exploiting intense XFEL...