Three-Dimensional Nanoscale Imaging of SiO2 Nanofiller in Styrene-Butadiene Rubber with High-Resolution and High-Sensitivity Ptychographic X-ray Computed Tomography.

SiO2 aggregates in styrene-butadiene rubber (SBR) were observed using ptychographic X-ray computed tomography (PXCT). The rubber composites were illuminated with X-rays focused by total reflection focusing mirrors, and the ptychographic diffraction patterns were collected using a CITIUS detector in the range of -75° to +75° angle of incidence. The projection images of the rubber composites were reconstructed with a two-dimensional resolution of 76 nm, and no significant structural changes were observed during the PXCT measurements.

Broadband Quasielastic Scattering Spectroscopy Using a Multiline Frequency Comblike Spectrum in the Hard X-Ray Region.

We developed a novel quasielastic scattering spectroscopy system that uses a multiline frequency comblike resolution function to overcome the limit on the accessible timescale imposed by the inherent single-energy resolution of conventional spectroscopy systems. The new multiline system possesses multiple resolutions and can efficiently cover a wide time range, from 100 ps to 100 ns, where x-ray-based dynamic measurement techniques are being actively developed. It enables visualization of the relaxation shape and wave-number-dependent dynamic behavior using a two-dimensional detector, as demonstrated for the natural polymer polybutadine without deuteration.

High-throughput and high-resolution powder X-ray diffractometer consisting of six sets of 2D CdTe detectors with variable sample-to-detector distance and innovative automation system.

The demand for powder X-ray diffraction analysis continues to increase in a variety of scientific fields, as the excellent beam quality of high-brightness synchrotron light sources enables the acquisition of high-quality measurement data with high intensity and angular resolution. Synchrotron powder diffraction has enabled the rapid measurement of many samples and various in situ/operando experiments in nonambient sample environments. To meet the demands for even higher throughput measurements using high-energy X-rays at SPring-8, a high-throughput and high-resolution powder diffraction system has been developed.

Quantifying bunch-mode influence on photon-counting detectors at SPring-8.

Count-loss characteristics of photon-counting 2D detectors are demonstrated for eight bunch-modes at SPring-8 through Monte Carlo simulations. As an indicator, the effective maximum count rate was introduced to signify the X-ray intensity that the detector can count with a linearity of 1% or better after applying a count-loss correction in each bunch-mode. The effective maximum count rate is revealed to vary depending on the bunch-mode and the intrinsic dead time of the detectors, ranging from 0.

Bragg coherent diffraction imaging with the CITIUS charge-integrating detector.

The CITIUS detector is a next-generation high-speed X-ray imaging detector. It has integrating-type pixels and is designed to show a consistent linear response at a frame rate of 17.4 kHz, which results in a saturation count rate of over 30 Mcps pixel when operating at an acquisition duty cycle close to 100%, and up to 20 times higher with special extended acquisition modes.

High-resolution and high-sensitivity X-ray ptychographic coherent diffraction imaging using the CITIUS detector.

Ptychographic coherent diffraction imaging (PCDI) is a synchrotron X-ray microscopy technique that provides high spatial resolution and a wide field of view. To improve the performance of PCDI, the performance of the synchrotron radiation source and imaging detector should be improved. In this study, ptychographic diffraction pattern measurements using the CITIUS high-speed X-ray image detector and the corresponding image reconstruction are reported.

Development and application of a tender X-ray ptychographic coherent diffraction imaging system on BL27SU at SPring-8.

Ptychographic coherent diffraction imaging (CDI) allows the visualization of both the structure and chemical state of materials on the nanoscale, and has been developed for use in the soft and hard X-ray regions. In this study, a ptychographic CDI system with pinhole or Fresnel zone-plate optics for use in the tender X-ray region (2-5 keV) was developed on beamline BL27SU at SPring-8, in which high-precision pinholes optimized for the tender energy range were used to obtain diffraction intensity patterns with a low background, and a temperature stabilization system was developed to reduce the drift of the sample position. A ptychography measurement of a 200 nm thick tantalum test chart was performed at an incident X-ray energy of 2.

Development of a scanning soft X-ray spectromicroscope to investigate local electronic structures on surfaces and interfaces of advanced materials under conditions ranging from low vacuum to helium atmosphere.

A scanning soft X-ray spectromicroscope was recently developed based mainly on the photon-in/photon-out measurement scheme for the investigation of local electronic structures on the surfaces and interfaces of advanced materials under conditions ranging from low vacuum to helium atmosphere. The apparatus was installed at the soft X-ray beamline (BL17SU) at SPring-8. The characteristic features of the apparatus are described in detail.

Ultrafast Structural Dynamics of Nanoparticles in Intense Laser Fields.

Femtosecond laser pulses have opened new frontiers for the study of ultrafast phase transitions and nonequilibrium states of matter. In this Letter, we report on structural dynamics in atomic clusters pumped with intense near-infrared (NIR) pulses into a nanoplasma state. Employing wide-angle scattering with intense femtosecond x-ray pulses from a free-electron laser source, we find that highly excited xenon nanoparticles retain their crystalline bulk structure and density in the inner core long after the driving NIR pulse.

A statistical approach to correct X-ray response non-uniformity in microstrip detectors for high-accuracy and high-resolution total-scattering measurements.

An unbiased approach to correct X-ray response non-uniformity in microstrip detectors has been developed based on the statistical estimation that the scattering intensity at a fixed angle from an object is expected to be constant within the Poisson noise. Raw scattering data of SiO glass measured by a microstrip detector module was found to show an accuracy of 12σ at an intensity of 10 photons, where σ is the standard deviation according to the Poisson noise. The conventional flat-field calibration has failed in correcting the data, whereas the alternative approach used in this article successfully improved the accuracy from 12σ to 2σ.

Development of an X-ray imaging detector to resolve 200 nm line-and-space patterns by using transparent ceramics layers bonded by solid-state diffusion.

A high-resolution lens-coupled X-ray imaging detector equipped with a thin-layer transparent ceramics scintillator has been developed. The scintillator consists of a 5 μm thick Ce-doped LuAlO layer (LuAG:Ce) bonded onto the support substrate of the non-doped LuAG ceramics by using a solid-state diffusion technique. Secondary electron microscopy of the bonded interface indicated that the crystal grains were densely packed without any pores in the optical wavelength scale, indicating a quasi-uniform refractive index across the interface.

Advancement of X-ray radiography using microfocus X-ray source in conjunction with amplitude grating and SOI pixel detector, SOPHIAS.

We show how to improve microfocus X-ray radiography by using the SOPHIAS silicon-on-insulator pixel detector in conjunction with an amplitude grating. Single-exposure multi-energy absorption and differential phase contrast imaging was performed using the single amplitude grating method. The sensitivity in differential phase contrast imaging in a two-pixel-pitch setup was enhanced by 39% in comparison with the previously reported method [Rev.

Software for the data analysis of the arrival-timing monitor at SACLA.

X-ray free-electron laser (XFEL) pulses from SPring-8 Ångstrom Compact free-electron LAser (SACLA) with a temporal duration of <10 fs have provided a variety of benefits in scientific research. In a previous study, an arrival-timing monitor was developed to improve the temporal resolution in pump-probe experiments at beamline 3 by rearranging data in the order of the arrival-timing jitter between the XFEL and the synchronized optical laser pulses. This paper presents Timing Monitor Analyzer (TMA), a software package by which users can conveniently obtain arrival-timing data in the analysis environment at SACLA.

Crystal Structures of Human Orexin 2 Receptor Bound to the Subtype-Selective Antagonist EMPA.

Orexin peptides in the brain regulate physiological functions such as the sleep-wake cycle, and are thus drug targets for the treatment of insomnia. Using serial femtosecond crystallography and multi-crystal data collection with a synchrotron light source, we determined structures of human orexin 2 receptor in complex with the subtype-selective antagonist EMPA (N-ethyl-2-[(6-methoxy-pyridin-3-yl)-(toluene-2-sulfonyl)-amino]-N-pyridin-3-ylmethyl-acetamide) at 2.30-Å and 1.

Experimental phase determination with selenomethionine or mercury-derivatization in serial femtosecond crystallography.

Serial femtosecond crystallography (SFX) using X-ray free-electron lasers (XFELs) holds enormous potential for the structure determination of proteins for which it is difficult to produce large and high-quality crystals. SFX has been applied to various systems, but rarely to proteins that have previously unknown structures. Consequently, the majority of previously obtained SFX structures have been solved by the molecular replacement method.

Nanosecond pump-probe device for time-resolved serial femtosecond crystallography developed at SACLA.

X-ray free-electron lasers (XFELs) have opened new opportunities for time-resolved X-ray crystallography. Here a nanosecond optical-pump XFEL-probe device developed for time-resolved serial femtosecond crystallography (TR-SFX) studies of photo-induced reactions in proteins at the SPring-8 Angstrom Compact free-electron LAser (SACLA) is reported. The optical-fiber-based system is a good choice for a quick setup in a limited beam time and allows pump illumination from two directions to achieve high excitation efficiency of protein microcrystals.

Hydroxyethyl cellulose matrix applied to serial crystallography.

Serial femtosecond crystallography (SFX) allows structures of proteins to be determined at room temperature with minimal radiation damage. A highly viscous matrix acts as a crystal carrier for serial sample loading at a low flow rate that enables the determination of the structure, while requiring consumption of less than 1 mg of the sample. However, a reliable and versatile carrier matrix for a wide variety of protein samples is still elusive.

Atomic resolution structure of serine protease proteinase K at ambient temperature.

Atomic resolution structures (beyond 1.20 Å) at ambient temperature, which is usually hampered by the radiation damage in synchrotron X-ray crystallography (SRX), will add to our understanding of the structure-function relationships of enzymes. Serial femtosecond crystallography (SFX) has attracted surging interest by providing a route to bypass such challenges.

Light-induced structural changes and the site of O=O bond formation in PSII caught by XFEL.

Photosystem II (PSII) is a huge membrane-protein complex consisting of 20 different subunits with a total molecular mass of 350 kDa for a monomer. It catalyses light-driven water oxidation at its catalytic centre, the oxygen-evolving complex (OEC). The structure of PSII has been analysed at 1.

A three-dimensional movie of structural changes in bacteriorhodopsin.

Bacteriorhodopsin (bR) is a light-driven proton pump and a model membrane transport protein. We used time-resolved serial femtosecond crystallography at an x-ray free electron laser to visualize conformational changes in bR from nanoseconds to milliseconds following photoactivation. An initially twisted retinal chromophore displaces a conserved tryptophan residue of transmembrane helix F on the cytoplasmic side of the protein while dislodging a key water molecule on the extracellular side.