A simple approach exploits quantum properties to justify the dependence on γ4 of the total synchrotron emitted power. It also clarifies some apparent puzzles and brings to light the underlying, multiple relativistic phenomena.

X-ray double-crystal monochromators face a shift of the exit beam when the Bragg angle and thus the transmitted photon energy changes. This can be compensated for by moving one or both crystals accordingly. In the case of monolithic channel-cut crystals, which exhibit utmost stability, the shift of the monochromated beam is inevitable. Here we report performance tests of novel, asymmetrically cut, channel-cut crystals which reduce the beam movements by more than a factor of 20 relative to the symmetric case over the typical energy range of an EXAFS spectrum at the Cu K-edge. In addition, the presented formulas for the beam offset including the asymmetry angle directly indicate the importance of this value, which has been commonly neglected so far in the operation of double-crystal monochromators.

An alternative approach to hard-X-ray photoelectron spectroscopy (HAXPES) has been established. The instrumental key feature is an increase of the dimensionality of the recording scheme from 2D to 3D. A high-energy momentum microscope detects electrons with initial kinetic energies up to 8 keV with a k-resolution of 0.025 Å−1, equivalent to an angular resolution of 0.034°. A special objective lens with k-space acceptance up to 25 Å−1 allows for simultaneous full-field imaging of many Brillouin zones. Combined with time-of-flight (ToF) parallel energy recording this yields maximum parallelization. Thanks to the high brilliance (1013 hν s−1 in a spot of <20 µm diameter) of beamline P22 at PETRA III (Hamburg, Germany), the microscope set a benchmark in HAXPES recording speed, i.e. several million counts per second for core-level signals and one million for d-bands of transition metals. The concept of tomographic k-space mapping established using soft X-rays works equally well in the hard X-ray range. Sharp valence band k-patterns of Re, collected at an excitation energy of 6 keV, correspond to direct transitions to the 28th repeated Brillouin zone. Measured total energy resolutions (photon bandwidth plus ToF-resolution) are 62 meV and 180 meV FWHM at 5.977 keV for monochromator crystals Si(333) and Si(311) and 450 meV at 4.0 keV for Si(111). Hard X-ray photoelectron diffraction (hXPD) patterns with rich fine structure are recorded within minutes. The short photoelectron wavelength (10% of the interatomic distance) `amplifies' phase differences, making full-field hXPD a sensitive structural tool.

The transmission of the optical components of the Bernina branch of the Aramis beamline at SwissFEL has been measured with an X-ray gas monitor from DESY and compared with a PSI gas detector upstream of the optical components. The transmission efficiencies of the Mo, Si and SiC mirror coatings of the Aramis beamline and the various other in-beam components were evaluated and compared with theoretical calculations, showing an agreement of 6% or better in all cases. The experiment has also shown the efficacy of the high-harmonic rejection mirrors at the Bernina branch of the Aramis beamline at SwissFEL, and characterized the transmission efficiency of the on-line spectrometer in the Aramis beamline. The theoretical transmission of the mirror coatings match the experimental data to within 7%. The accuracy of these measurements was checked against a radiative bolometer from a Japanese collaboration and found to agree to a level of 4% or better. Further comparisons with a diamond detector from a US-based inter-institute collaboration demonstrated a good agreement for the attenuator settings of the beamline.

Calibration of area detectors from powder diffraction standards is widely used at synchrotron beamlines. From a single diffraction image, it is not possible to determine both the sample-to-detector distance and the wavelength, but, with images taken from multiple positions along the beam direction and where the relative displacement is known, the sample-to-detector distance and wavelength can both be determined with good precision. An example calibration using the GSAS-II software package is presented.

The design and performance of the high-resolution wavelength-dispersive multi-crystal von Hamos-type spectrometer at PETRA III beamline P64 are described. Extended analyzer crystal collection available at the beamline allows coverage of a broad energy range from 5 keV to 20 keV with an energy resolution of 0.35–1 eV. Particular attention was paid to enabling two-color measurements by a combination of two types of analyzer crystals and two two-dimensional detectors. The performance of the spectrometer is demonstrated by elastic-line and emission-line measurements on various compounds.

A new Rococo 2 X-ray fluorescence detector was implemented into the cryogenic sample environment at the Hard X-ray Micro/Nano-Probe beamline P06 at PETRA III, DESY, Hamburg, Germany. A four sensor-field cloverleaf design is optimized for the investigation of planar samples and operates in a backscattering geometry resulting in a large solid angle of up to 1.1 steradian. The detector, coupled with the Xspress 3 pulse processor, enables measurements at high count rates of up to 106 counts per second per sensor. The measured energy resolution of ∼129 eV (Mn Kα at 10000 counts s−1) is only minimally impaired at the highest count rates. The resulting high detection sensitivity allows for an accurate determination of trace element distributions such as in thin frozen hydrated biological specimens. First proof-of-principle measurements using continuous-movement 2D scans of frozen hydrated HeLa cells as a model system are reported to demonstrate the potential of the new detection system.

A simple and robust tool for spatio-temporal overlap of THz and XUV pulses in in-vacuum pump–probe experiments is presented. The technique exploits ultrafast changes of the optical properties in semiconductors (i.e. silicon) driven by ultrashort XUV pulses that are probed by THz pulses. This work demonstrates that this tool can be used for a large range of XUV fluences that are significantly lower than when probing by visible and near-infrared pulses. This tool is mainly targeted at emerging X-ray free-electron laser facilities, but can be utilized also at table-top high-harmonics sources.

The performance of the recently commissioned spectrometer PEAXIS for resonant inelastic soft X-ray scattering (RIXS) and X-ray photoelectron spectroscopy and its hosting beamline U41-PEAXIS at the BESSY II synchrotron are characterized. The beamline provides linearly polarized light from 180 eV to 1600 eV allowing for RIXS measurements in the range 200–1200 eV. The monochromator optics can be operated in different configurations to provide either high flux with up to 1012 photons s−1 within the focal spot at the sample or high energy resolution with a full width at half maximum of <40 meV at an incident photon energy of ∼400 eV. The measured total energy resolution of the RIXS spectrometer is in very good agreement with theoretically predicted values obtained by ray-tracing simulations. PEAXIS features a 5 m-long RIXS spectrometer arm that can be continuously rotated about the sample position by 106° within the horizontal photon scattering plane, thus enabling the study of momentum-transfer-dependent excitations. Selected scientific examples are presented to demonstrate the instrument capabilities, including measurements of excitations in single-crystalline NiO and in liquid acetone employing a fluid cell sample manipulator. Planned upgrades of the beamline and the RIXS spectrometer to further increase the energy resolution to ∼100 meV at 1000 eV incident photon energy are discussed.

Small-animal physiology studies are typically complicated, but the level of complexity is greatly increased when performing live-animal X-ray imaging studies at synchrotron and compact light sources. This group has extensive experience in these types of studies at the SPring-8 and Australian synchrotrons, as well as the Munich Compact Light Source. These experimental settings produce unique challenges. Experiments are always performed in an isolated radiation enclosure not specifically designed for live-animal imaging. This requires equipment adapted to physiological monitoring and test-substance delivery, as well as shuttering to reduce the radiation dose. Experiment designs must also take into account the fixed location, size and orientation of the X-ray beam. This article describes the techniques developed to overcome the challenges involved in respiratory X-ray imaging of live animals at synchrotrons, now enabling increasingly sophisticated imaging protocols.

Multilayer monochromator devices are commonly used at (imaging) beamlines of synchrotron facilities to shape the X-ray beam to relatively small bandwidth and high intensity. However, stripe artefacts are often observed and can deteriorate the image quality. Although the intensity distribution of these artefacts has been described in the literature, their spectral distribution is currently unknown. To assess the spatio-spectral properties of the monochromated X-ray beam, the direct beam has been measured for the first time using a hyperspectral X-ray detector. The results show a large number of spectral features with different spatial distributions for a [Ru, B4C] strip monochromator, associated primarily with the higher-order harmonics of the undulator and monochromator. It is found that their relative contributions are sufficiently low to avoid an influence on the imaging data. The [V, B4C] strip suppresses these high-order harmonics even more than the former, yet at the cost of reduced efficiency.

A new diamond-anvil cell apparatus for in situ synchrotron X-ray diffraction measurements of liquids and glasses, at pressures from ambient to 5 GPa and temperatures from ambient to 1300 K, is reported. This portable setup enables in situ monitoring of the melting of complex compounds and the determination of the structure and properties of melts under moderately high pressure and high temperature conditions relevant to industrial processes and magmatic processes in the Earth's crust and shallow mantle. The device was constructed according to a modified Bassett-type hydro­thermal diamond-anvil cell design with a large angular opening (θ = 95°). This paper reports the successful application of this device to record in situ synchrotron X-ray diffraction of liquid Ga and synthetic PbSiO3 glass to 1100 K and 3 GPa.

A simple two-spindle based lathe system for the preparation of cylindrical samples intended for X-ray tomography is presented. The setup can operate at room temperature as well as under cryogenic conditions, allowing the preparation of samples down to 20 and 50 µm in diameter, respectively, within minutes. Case studies are presented involving the preparation of a brittle biomineral brachiopod shell and cryogenically fixed soft brain tissue, and their examination by means of ptychographic X-ray computed tomography reveals the preparation method to be mainly free from causing artefacts. Since this lathe system easily yields near-cylindrical samples ideal for tomography, a usage for a wide variety of otherwise challenging specimens is anticipated, in addition to potential use as a time- and cost-saving tool prior to focused ion-beam milling. Fast sample preparation becomes especially important in relation to shorter measurement times expected in next-generation synchrotron sources.

A new resonant inelastic X-ray scattering (RIXS) instrument has been constructed at beamline P01 of the PETRA III synchrotron. This instrument has been named IRIXS (intermediate X-ray energy RIXS) and is dedicated to X-rays in the tender-energy regime (2.5–3.5 keV). The range covers the L2,3 absorption edges of many of the 4d elements (Mo, Tc, Ru, Rh, Pd and Ag), offering a unique opportunity to study their low-energy magnetic and charge excitations. The IRIXS instrument is currently operating at the Ru L3-edge (2840 eV) but can be extended to the other 4d elements using the existing concept. The incoming photons are monochromated with a four-bounce Si(111) monochromator, while the energy analysis of the outgoing photons is performed by a diced spherical crystal analyzer featuring (102) lattice planes of quartz (SiO2). A total resolution of 100 meV (full width at half-maximum) has been achieved at the Ru L3-edge, a number that is in excellent agreement with ray-tracing simulations.

Serial synchrotron crystallography (SSX) is an emerging technique for static and time-resolved protein structure determination. Using specifically patterned silicon chips for sample delivery, the `hit-and-return' (HARE) protocol allows for efficient time-resolved data collection. The specific pattern of the crystal wells in the HARE chip provides direct access to many discrete time points. HARE chips allow for optical excitation as well as on-chip mixing for reaction initiation, making a large number of protein systems amenable to time-resolved studies. Loading of protein microcrystals onto the HARE chip is streamlined by a novel vacuum loading platform that allows fine-tuning of suction strength while maintaining a humid environment to prevent crystal dehydration. To enable the widespread use of time-resolved serial synchrotron crystallography (TR-SSX), detailed technical descriptions of a set of accessories that facilitate TR-SSX workflows are provided.

MAX IV is a fourth-generation, or diffraction-limited, synchrotron light source with a number of state-of-the-art beamlines. The performance of a beamline is, to a high degree, set by the energy resolution it can achieve, which in turn is governed to a large extent by the monochromator. During the design phase of a monochromator, the mechanical requirements must be fully understood and met with margin. During commissioning, the performance must be verified and optimized. In this paper, six soft X-ray monochromators at MAX IV beamlines (Bloch, Veritas, HIPPIE, SPECIES, FinEstBeAMS and SoftiMAX) are examined with a focus on their resolving power, energy range and the time required to change measurement range, as those parameters are dependent on each other. The monochromators have a modern commercial design, planned and developed in close collaboration with the vendors. This paper aims to present the current status of the commissioning at MAX IV with emphasis on elucidating the mechanical limitations on the performance of the monochromators. It contains analysis of the outcome and our approach to achieve fast and high-resolution monochromators.

The time evolution of the electron density and the resulting time dependence of the X-ray polarizability of a crystal irradiated by highly intense XFEL femtosecond pulses is investigated theoretically. Rate equations for bound electrons and the Boltzmann equation for the unbound electron gas are used in calculations.

Contributions of experimental and selected theoretical charge-density research to medicinal chemistry are reviewed; combining experimental methods from high-resolution small-molecule and macromolecular crystallography with theory proves to be fruitful.

Possibilities in auxiliary technique combinations with small- and wide-angle X ray scattering are described, as well as more complicated sample environments used in X-ray and neutron scattering.

A method is presented for the automatic building of nucleotide chains into electron density which is fast enough to be used in interactive model-building software. Likely nucleotides lying in the vicinity of the current view are located and then grown into connected chains in a fraction of a second. When this development is combined with existing tools, assisted manual model building is as simple as or simpler than for proteins.

Pressure can play a key role in probing the structure and dynamics of membrane assemblies, and is also critical to the biology and adaptation of deep-sea organisms. This article presents an overview of the effect of pressure on the structure of membranes and recent developments in high-pressure instrumentation.

Rietveld/MEM analysis applied to synchrotron powder X-ray diffraction data of dehydrated CHA zeolites with catalytically active Cu2+ reveals Cu2+ in both the six- and eight-membered rings in the CHA framework, providing the first complete structural model that accounts for all Cu2+. Density functional theory calculations are used to corroborate the experimental structure and to discuss the Cu2+ coordination in terms of the Al distribution in the framework.

The structure and function of dioxygenases in histone demethylation and DNA/RNA dimethylation are discussed.

A neutron crystallographic study of perdeuterated transthyretin reveals important aspects of the structure relating to its stability and its propensity to form fibrils, as well as evidence of a single water molecule that affects the symmetry of the two binding pockets.

The X-ray diffraction/X-ray fluorescence instrument CheMin on the Curiosity rover is a shoebox-sized device using transmission geometry and an energy-discriminating CCD detector. The instrument has returned the first X-ray diffraction data for soil and drilled samples from Mars outcrops, revealing a suite of primary basaltic minerals, amorphous components and varied hydrous alteration products including phyllosilicates.

PLEASE REDUCE TO 1-2 SENTENCES. The capability of X-ray diffraction for the microstructure investigations of metastable systems is illustrated on the example of thin films of titanium aluminium nitrides with high aluminium content, which are supersaturated and partially decomposed. In addition to the chemical composition, the surface mobility of the deposited species was employed as a factor influencing the microstructure of the thin films. It is shown how the micromechanical properties of the partially decomposed (Ti,Al)N thin films, which were deduced from the synchrotron diffraction experiments, are related to the thin film microstructure and to the decomposition mechanism. The prominent role of the crystallographic anisotropy of the macroscopic and microscopic lattice deformations in the understanding of the micromechanical properties is addressed.

Kent earthquake 'causes homes to shake'  BBC News

True and magnetic north to synch at Greenwich for first time in 360 years  New Atlas

Ripon sinkhole concerns halt Harrogate council homes plans  BBC News

UK government's fracking 'ban' has a convenient loophole  The Conversation UK

Did you feel earthquake?  Stamford Mercury

British Geological Survey recreates Great Britain in Minecraft  Eurogamer.net

Leading scientists set out resource challenge of meeting net zero emissions in the UK by 2050  The Natural History Museum

Fracking in the UK was doomed a decade ago – Tories have wasted precious time on a fossil fuel fantasy  The Conversation UK

151 homes for Keyworth recommended for approval by council  West Bridgford Wire

Decision day looms over Ellesmere Port shale gas plan  Cheshire Live

True North to align with Magnetic North at Greenwich for first time in 360 years  Telegraph.co.uk

The Ground Shakes Under Britain Again, Forcing the Government to Ban Fracking  Fortune

Fast trashion: Exhibition of garments made from street-litter opens at Imperial | Imperial News  Imperial College London

Compasses at Greenwich Are About to Do Something Not Observed in Over 300 Years  ScienceAlert

Shift in Earth’s magnetic north throws navigators off course  Financial Times

London soil pollution worst on former Blitz bomb sites  Chemistry World

UK's only active fracking site near Blackpool records largest ever earth tremor as homeowners complain of windows shaking  iNews

Earthquake strikes Sussex/Surrey border | Meridian - ITV News  ITV News

Viewpoint: UK government should pump money into computers for science  Science Business

Scottish Highlands hit by earthquake with magnitude measuring 2.3  The Scottish Sun

Dr Tim Gregory Works with a Meteorite That's Older Than The Earth  LeftLion

Cornwall earthquake: Homes shake in Helston  BBC News

Earth scientists plan to meld massive databases into a 'geological Google'  Science Magazine