A5067805786- Advanced X-ray Imaging Techniques
- Advanced Electron Microscopy Techniques and Applications
- X-ray Spectroscopy and Fluorescence Analysis
- Crystallography and Radiation Phenomena
- Material Dynamics and Properties
- Particle Accelerators and Free-Electron Lasers
- Magnetic properties of thin films
- Spectroscopy and Quantum Chemical Studies
- Laser-Plasma Interactions and Diagnostics
- Metallic Glasses and Amorphous Alloys
- Enzyme Structure and Function
- Glass properties and applications
- Advanced MRI Techniques and Applications
- Terahertz technology and applications
- Quantum and electron transport phenomena
- Force Microscopy Techniques and Applications
- Magnetic Properties and Applications
- Magnetic Properties of Alloys
- Physics of Superconductivity and Magnetism
- Phase Equilibria and Thermodynamics
- Magneto-Optical Properties and Applications
- Quantum, superfluid, helium dynamics
- Clay minerals and soil interactions
- Quasicrystal Structures and Properties
- Diamond and Carbon-based Materials Research
Deutsches Elektronen-Synchrotron DESY
2015-2024
Technical University of Denmark
2003-2005
Institute of Structure of Matter
2005
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...
We measured the coherence properties of free-electron laser SACLA on a single shot basis at an X-ray energy 8 keV. By analysing small-angle scattering speckle patterns from colloidal dispersions we found degree transverse βt = 0.79 ± 0.09. Taking detector into account, developed simulation model in oder to determine intensity histograms. Finally calculated time τc 0.1 fs and pulse duration 5.2 which corresponds with previous predictions.
Abstract The dynamics of liquid water feature a variety time scales, ranging from extremely fast ballistic-like thermal motion, to slower molecular diffusion and hydrogen-bond rearrangements. Here, we utilize coherent X-ray pulses investigate the sub-100 fs equilibrium ambient conditions down supercooled temperatures. This novel approach utilizes inherent capability speckle visibility spectroscopy measure intermolecular with lengthscale selectivity, by measuring oxygen motion in momentum...
One of the important challenges in condensed matter science is to understand ultrafast, atomic-scale fluctuations that dictate dynamic processes equilibrium and non-equilibrium materials. Here, we report an step towards reaching goal by using a state-of-the-art perfect crystal based split-and-delay system, capable splitting individual X-ray pulses introducing femtosecond nanosecond time delays. We show results ultrafast hard photon correlation spectroscopy experiment at LCLS where split were...
X-ray photon correlation spectroscopy (XPCS) enables the study of sample dynamics between micrometer and atomic length scales. As a coherent scattering technique, it benefits from increased brilliance next-generation synchrotron radiation Free-Electron Laser (FEL) sources. In this article, we will introduce XPCS concepts review latest developments with special attention on extension accessible time scales to sub-μs application at FELs. Furthermore, discuss future opportunities related...
A prototype device capable of splitting an x-ray pulse into two adjustable fractions, delaying one them with the aim to perform photon correlation spectroscopy and pump-probe type studies, was designed, manufactured, tested. The utilizes eight perfect silicon crystals in vertical 90 degrees scattering geometry. Its performance has been verified 8.39 keV synchrotron radiation. measured throughput a Si(333) premonochromator at under ambient conditions is 0.6%. Time delays up 2.62 ns have...
A hard X-ray delay line capable of splitting and delaying single pulses has been developed with the aim performing photon correlation spectroscopy (XPCS) pump-probe experiments at free-electron laser sources. The performance device was tested 8.39 keV synchrotron radiation. Time delays up to 2.95 ns have demonstrated. feasibility for XPCS studies by recording static speckle patterns. achieved contrast 56% indicates possibility ultra-fast line.
We report a comprehensive joint experimental-theoretical study of the equilibrium pair-structure and short-time diffusion in aqueous suspensions highly charged poly-acrylate (PA) spheres colloidal fluid phase. Low-polydispersity PA sphere systems with two different hard-core radii, R(0) = 542 1117 Å, are explored over wide range concentrations salinities using static dynamic light scattering (DLS), small angle x-ray scattering, photon correlation spectroscopy (XPCS). The measured functions...
Stimuli-responsive polymers are an important class of materials with many applications in nanotechnology and drug delivery. The most prominent one is poly- N -isopropylacrylamide (PNIPAm). characterization the kinetics its change after a temperature jump still lively research topic, especially at nanometer-length scales where it not possible to rely on conventional microscopic techniques. Here, we measured real time collapse PNIPAm shell silica nanoparticles megahertz x-ray photon...
The single shot based coherence properties of hard x-ray pulses from the Linac Coherent Light Source (LCLS) were measured by analyzing coherent diffraction patterns nano-particles and gold nanopowder.The intensity histogram small angle scattering ring reveals fully transversely nature LCLS beam with a number transverse mode M s = 1.1.On other hand, speckle contrasts at large wavevector yields information about longitudinal radiation after silicon (111) monochromator.The quantitative...
Pressure effects on glass transition temperature and supercooled liquid region of a Zr46.8Ti8.2Cu7.5Ni10Be27.5 bulk have been investigated by performing in situ high-temperature high-pressure x-ray powder diffraction measurements using synchrotron radiation. The was detected from the change slope peak position as function temperature. It is found that increases with pressure 4.4 K/GPa for glass, range decreases 2.9 0–2.2 GPa. This method opens possibility to study effect process glassy...
Abstract Hard X-ray free electron lasers allow for the first time to access dynamics of condensed matter samples ranging from femtoseconds several hundred seconds. In particular, exceptional large transverse coherence pulses and high time-averaged flux promises reach length scales that have not been accessible up now with storage ring based sources. However, due fluctuations originating stochastic nature self-amplified spontaneous emission (SASE) process application well established...
Many soft-matter systems are composed of macromolecules or nanoparticles suspended in water. The characteristic times at intrinsic length scales a few nanometres fall therefore the microsecond and sub-microsecond time regimes. With development free-electron lasers (FELs) fourth-generation synchrotron light-sources, time-resolved experiments such ranges will become routinely accessible near future. In present work we report our findings on prototypical systems, charge-stabilized silica...
The controlled manipulation of spins on ultrashort timescales is among the most promising solutions for novel high-speed and low-power-consumption spintronic magnetic recording applications. To do so, terahertz (THz) light pulses can be used to drive coherent magnetization dynamics in ferromagnetic thin films. We were able resolve these nanoscale employing THz-pump x-ray resonant scattering from labyrinth-type domain network a Co/Pt multilayer with perpendicular anisotropy. Our results...
We report on the feasibility of high wavevector temporal speckle correlation measurements at world's first hard x-ray free electron laser, Linac Coherent Light Source (LCLS). Due to chaotic nature LCLS, spectral profile radiation fluctuates a pulse-to-pulse basis. Its impact determination single shot contrast in wide angle scattering geometry is investigated by analyzing FEL power spectra that are simulated based nominal operational parameters LCLS. Ultimately, potential scheme deliver...
A hard X-ray delay line device capable of splitting single FEL pulses into two adjustable fractions and recombining them with the goal performing Photon Correlation Spectroscopy pump - probe type studies was designed. The performance has been verified at XPP XCS instruments LCLS. measured throughput 7.9 keV is 3.6%. coherence properties LCLS beam passing through were investigated by analyzing speckle patterns produced pulses. high contrast 0.69 found, indicating feasibility based experiments line.
X-ray photon correlation spectroscopy (XPCS) is a routine technique to study slow dynamics in complex systems at storage-ring sources. Achieving nanosecond time resolution with the conventional XPCS is, however, still an experimentally challenging task requiring fast detectors and sufficient flux. Here, result of colloidal shown by employing adaptive gain integrating pixel detector (AGIPD) operated frame rates intrinsic pulse structure storage ring. Correlation functions from single-pulse...
Hydrated proteins undergo a transition in the deeply supercooled regime, which is attributed to rapid changes hydration water and protein structural dynamics. Here, we investigate nanoscale stress–relaxation hydrated lysozyme stimulated probed by X-ray Photon Correlation Spectroscopy (XPCS). This approach allows us access dynamics regime (T = 180 K), typically not accessible through equilibrium methods. The observed dynamic response collective as system transitions from jammed granular state...
The application of X-ray photon correlation spectroscopy (XPCS) at free-electron laser (FEL) facilities enables, for the first time, study dynamics on a (sub-)nanometre scale in an unreached time range between femtoseconds and seconds. For soft-matter materials, radiation damage is major limitation when going beyond single-shot applications. Here, XPCS presented hard FEL radiation-sensitive polymeric poly( N -isopropylacrylamide) (PNIPAM) nanoparticles. aqueous suspensions densely packed...
The advent of X-ray free-electron lasers (XFELs) has revolutionized fundamental science, from atomic to condensed matter physics, chemistry biology, giving researchers access X-rays with unprecedented brightness, coherence and pulse duration. All XFEL facilities built until recently provided pulses at a relatively low repetition rate, limited data statistics. Here, results the first megahertz-repetition-rate scattering experiments Spectroscopy Coherent Scattering (SCS) instrument European...
We report on high pressure small angle x-ray scattering suspensions of colloidal crystallites in water. The made out charge-stabilized poly-acrylate particles exhibit a complex dependence which is based the specific properties suspending medium dominant effect compression caused by In addition, we find indications that also electrostatic system, i.e. particle charge and dissociation ions, might play role for samples. data further suggest metastable state induced shear-induced melting can...
In this paper we describe a setup for x-ray scattering experiments on complex fluids using liquid jet. The supports Small and Wide Angle X-ray Scattering (SAXS/WAXS) geometries. jet is formed by gas-dynamic virtual nozzle (GDVN) allowing diameters ranging between 1 μm 20 at length of several hundred μm. To control properties such as length, diameter, or flow rate, the instrument equipped with diagnostic tools. Three microscopes are installed to quantify dimensions stability in situ. has been...
A compact hard X-ray split-and-delay line for studying ultrafast dynamics at free-electron laser sources is presented. The device capable of splitting a single pulse into two fractions to introduce time delays from -5 815 ps with femtosecond resolution. can operate in wide and continuous energy range between 7 16 keV. Compact dimensions 60 × 30 cm total weight about kg make it portable suitable direct installation an experimental hutch. concept the based on crystal diffraction. piezo-driven...