Foreword to the special virtual issue on X-ray free-electron lasers

A virtual special issue of Journal of Synchrotron Radiation advances in the field of X-ray free-electron lasers.

High-efficiency ultra-precision comparator for d-spacing mapping measurement of silicon

The development of a wide-beam ultra-precision d-spacing mapping measurement system that is more than ten times faster than the previous pencil-beam method is presented.

Measurement and compensation of misalignment in double-sided hard X-ray Fresnel zone plates

A simple and reliable way of characterizing double-sided hard X-ray Fresnel zone plates is presented. The measurements are performed in an X-ray tube-based setup where a near-monochromatic spectrum is isolated by differential measurements with a Cu and an Ni filter.

Focusing with saw-tooth refractive lenses at a high-energy X-ray beamline

The implementation of saw-tooth refractive lenses at the APS 1-ID high-energy X-ray beamline is presented.

A single-crystal diamond X-ray pixel detector with embedded graphitic electrodes

The first experimental results from a new type of transmissive synchrotron X-ray diagnostic instrument are presented. A chemical-vapour-deposition diamond plate with graphitic electrodes and a modulation lock-in signal acquisition technique are used to image the X-ray beam.

The ePix10k 2-megapixel hard X-ray detector at LCLS

The ePix10ka2M is a new large area detector specifically developed for X-ray free-electron laser applications. Here the detector parameters and performance are presented, as well as the detector nonlinearity as characterized by diffuse scattering measurements at the Linac Coherent Light Source.

Fast continuous measurement of synchrotron powder diffraction synchronized with controlling gas and vapour pressures at beamline BL02B2 of SPring-8

An in situ high-resolution powder diffraction measurement system synchronized with controlling gas and vapour pressures is presented. This system enables one to perform both automatic in situ and millisecond time-resolved measurements under gas pressures.

Soft X-ray diffraction patterns measured by a LiF detector with sub-micrometre resolution and an ultimate dynamic range

In this study, a photoluminescence lithium fluoride (LiF) detector demonstrates its capabilities in X-ray imaging at extreme absorbed doses with an ultimate dynamic range of ∼10⁷ and sub-micrometre spatial resolution, all from the perspective of experiments at synchrotron sources of the next generation. Response functions of the LiF detector are provided at the 500 eV photon-energy water-window band.

Estimating signal and noise of time-resolved X-ray solution scattering data at synchrotrons and XFELs

The simulation of a signal and signal-to-noice ratio for time-resolved X-ray solution scattering data is presented.

Full strain tensor measurements with X-ray diffraction and strain field mapping: a simulation study

A methodology to resolve the full strain tensor under commonly encountered loading modes in experiments is developed on the basis of simulations. This method can be implemented with simultaneous X-ray diffraction and imaging techniques.

Synchrotron X-ray diffraction investigation of the surface condition of artefacts from King Henry VIII's warship the Mary Rose

A new method using a high-sensitivity X-ray camera for a large-range diffraction pattern is presented; it confirms the effectiveness of over 35 years of conservation treatment for brass artefacts from the Mary Rose.

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

The development of a scanning soft X-ray spectromicroscope is described.

Zeeman quantum beats of helium Rydberg states excited by synchrotron radiation

Zeeman quantum beats of helium Rydberg states were measured with synchrotron radiation. It is proposed that the polarization characteristic of extreme ultraviolet light can be simply evaluated by the measurement of the Zeeman quantum beats.

Fluorescence-detected quick-scanning X-ray absorption spectroscopy

Application of time-resolved fluorescence-detection quick X-ray absorption spectroscopy using a partially depleted passivated implanted planar silicon detector at the SuperXAS beamline.

Comparative study of the around-Fermi electronic structure of 5d metals and metal-oxides by means of high-resolution X-ray emission and absorption spectroscopies

This work demonstrates how the combination of resonant and non-resonant X-ray emission spectroscopies supplemented with theoretical modelling allows for quantitative analysis of electronic states around Fermi, band gap energies and strength of crystal field splitting in 5d transition metal and metal-oxide materials.

A design of resonant inelastic X-ray scattering (RIXS) spectrometer for spatial- and time-resolved spectroscopy

The optical design of a soft X-ray spectrometer that utilizes Wolter mirrors to enable imaging-mode spectroscopy with a beam-size independent spatial resolution in, for example, tandem catalysts in reaction is presented. When such a spectrometer is used in pump–probe experiments to study the transient electron dynamics, the imaging capability of the Wolter mirrors can offer femtosecond time delay between the pump and probe beams with non-collinear wavefronts.

High-dynamic-range transmission-mode detection of synchrotron radiation using X-ray excited optical luminescence in diamond

A high-efficiency transmission-mode diamond X-ray scintillator is demonstrated for detection (imaging) of synchrotron beam profiles.

Qu­antifying redox heterogeneity in single-crystalline LiCoO₂ cathode particles

Nano-resolution spectro-tomography has been broadly applied to material studies. The polarization configuration of the synchrotron X-rays could affect the X-ray absorption near-edge structure fingerprint but is not considered in the conventional approach. The current study tackles this issue and proposes a solution for the case study of LiCoO₂ battery cathode particles.

Identification of Ca-rich dense granules in human platelets using scanning transmission X-ray microscopy

To complement the limitation of whole-mount transmission electron microscopy (TEM) for assessing dense granule deficiency, scanning transmission X-ray microscopy (STXM) was used to identify calcium-rich dense granules in human platelets. Based on STXM images of human platelets, their calcium maps were extracted to identify dense granules correctly and distinguish them from other granules such as α-granules.

Laser-induced metastable mixed phase of AuNi nanoparticles: a coherent X-ray diffraction imaging study

Coherent diffraction imaging in the forward-scattering geometry reveals AuNi nano alloy particles in a metastable mixed phase. The AuNi nanoparticles irradiated by nanosecond laser pulses exhibit the mixed phase overcoming the miscibility gap.

LamNI – an instrument for X-ray scanning microscopy in lamino­graphy geometry

A technical description of an instrument that allows 3D nano-imaging via ptychographic X-ray lamino­graphy is presented.

Linearly polarized X-ray fluorescence computed tomography based on a Thomson scattering light source: a Monte Carlo study

We examined the suppression of Compton scattering background in XFCT using the linearly polarized X-rays and the implementation feasibility of linearly polarized XFCT based on this type of light source, concerning the influence of phantom attenuation and the sampling strategy, its advantage over K-edge subtraction computed tomography, the imaging time, and the potential pulse pile-up effect by Monte Carlo simulations.

Versatile compact heater design for in situ nano-tomography by transmission X-ray microscopy

A compact high-temperature furnace optimized for in situ experiments with a transmission X-ray microscope is designed and fabricated. The furnace has high-temperature stability and minimal heat footprint to the ambient environment which are critical to high-quality experiments.

Qu­antitative three-dimensional nondestructive imaging of whole anaerobic ammonium-oxidizing bacteria

The three-dimensional structure of whole anammox bacteria based on synchrotron soft X-ray imaging is presented.

Radiochromic film dosimetry in synchrotron radiation breast computed tomography: a phantom study

The optimum geometry for the phase-contrast computed tomography examination of the breast using synchrotron radiation is investigated in terms of dose distribution in the breast, at a fixed value of mean glandular dose.

Synchrotron multimodal imaging in a whole cell reveals lipid droplet core organization

Cryo soft X-ray tomography and deep-ultraviolet transmittance imaging reveal partitioning of neutral lipids in a lipid droplet core. Furthermore, deep-ultraviolet transmittance and tryptophan/tyrosine auto-fluorescence multimodal imaging on living cells were combined to obtain complementary information on organelle chemical contents.

Validation study of small-angle X-ray scattering tensor tomography

Small-angle scattering tensor tomography allows for tomographic reconstruction of the 3D reciprocal space from voxels within a bulk volume. In this study, the nanostructure orientation and the scattering curve along different 3D directions are validated with data obtained from thin sections of the same sample.

Shack–Hartmann wavefront sensors based on 2D refractive lens arrays and super-resolution multi-contrast X-ray imaging

Super-resolution multi-contrast X-ray imaging performed using a Shack–Hartmann sensor for hard X-rays is presented.

Volt-per-Ångstrom terahertz fields from X-ray free-electron lasers

A rather modest upgrade of the GeV-level linear accelerator of modern X-ray free-electron lasers with purpose-built THz undulators allows generating intense, tunable and narrow-bandwidth THz pulses alongside the X-ray pulses. The enabling technological breakthroughs in accelerator physics are discussed and the arising new research possibilities are presented.

Measurement of the horizontal beam emittance of undulator radiation by tandem-double-slit optical system

The horizontal beam property in the phase space of undulator radiation was derived using a tandem-double-slit optical system. The net effective beam emittance was extracted by deconvoluting the Fraunhofer diffraction produced by the upstream slit in the phase space.

Solution scattering at the Life Science X-ray Scattering (LiX) beamline

Instrumentation and data processing for solution scattering at the LiX beamline are presented.

TEXS: in-vacuum tender X-ray emission spectrometer with 11 Johansson crystal analyzers

An in-vacuum tender X-ray emission spectrometer with an innovative mechanics allowing displacement of 11 cylindrical Johansson crystal analyzers in a non-dispersive Rowland circle geometry is presented.

High-energy-resolution inelastic X-ray scattering spectrometer at beamline 30-ID of the Advanced Photon Source

The design and capabilities of the momentum-resolved high-energy-resolution inelastic X-ray spectrometer (HERIX) at beamline 30-ID of the Advanced Photon Source are reported.

XTIP – the world's first beamline dedicated to the synchrotron X-ray scanning tunneling microscopy technique

A new beamline, XTIP, has been constructed at the Advanced Photon Source to deliver monochromatic soft X-rays of between 400 and 1900 eV for the emerging synchrotron X-ray scanning tunneling microscopy technique.

ID30A-3 (MASSIF-3) – a beamline for macromolecular crystallography at the ESRF with a small intense beam

ID30A-3, a highly intense mini-beam facility for macromolecular crystallography at the ESRF, is described..

A phase-retrieval toolbox for X-ray holography and tomography

This article describes scientific software made publicly available for phase retrieval in X-ray propagation imaging. The package is called HoloTomoToolbox and comprises a set of algorithms for phase retrieval in the direct-contrast regime, as well as in the holographic regime, which is used for high-resolution cone-beam synchrotron recordings. Further to this, a set of routines is included to facilitate the conversion of the 2D phase projections in a 3D tomogram.

The TELL automatic sample changer for macromolecular crystallography

The TELL sample changer has been developed at the Paul Scherrer Institute with a focus on speed, storage capacity and reliability, to serve the three macromolecular crystallography beamlines of the Swiss Light Source, as well as the SwissMX instrument at SwissFEL.