EIGER2 hybrid-photon-counting X-ray detectors for advanced synchrotron diffraction experiments

Multi-beam multi-slice X-ray ptychography

X-ray ptychography provides the highest resolution non-destructive imaging at synchrotron radiation facilities, and the efficiency of this method is crucial for coping with limited experimental time. Recent advancements in multi-beam ptychography have enabled larger fields of view, but spatial resolution for large 3D samples remains constrained by their thickness, requiring consideration of multiple scattering events. Although this challenge has been addressed using multi-slicing in conventional ptychography, the integration of multi-slicing with multi-beam ptychography has not yet been explored. Here we present the first successful combination of these two methods, enabling high-resolution imaging of nanofeatures at depths comparable to the lateral dimensions that can be addressed by state-of-the-art multi-beam ptychography. Our approach is robust, reproducible across different beamlines, and ready for broader application. It marks a significant advancement in the field, establishing a new foundation for high-resolution 3D imaging of larger, thicker samples.

Compact laser-driven plasma X-ray source for time-resolved diffraction, spectroscopy and imaging experiments at ELI Beamlines

In this work, experimentally measured characteristics of a kilohertz laser-driven Cu plasma X-ray source that was recently commissioned at the ELI Beamlines facility are reported. The source can be driven either by an in-house developed high-contrast sub-20 fs near-infrared terawatt laser based on optical parametric chirped-pulse amplification technology or by a more conventional Ti:sapphire laser delivering 12 mJ and 45 fs pulses. The X-ray source parameters obtained with the two driving lasers are compared. A measured photon flux of the order up to 1012 Kα photons s-1 (4π)-1 is reported. Furthermore, experimental platforms for ultrafast X-ray diffraction and X-ray absorption and emission spectroscopy based on the reported source are described.

Enhancing high-energy powder X-ray diffraction applications using a PILATUS4 CdTe detector

Hybrid photon counting detectors have significantly advanced synchrotron research. In particular, the introduction of large cadmium telluride-based detectors in 2015 enabled a whole new range of high-energy X-ray measurements. This article describes the specifications of the new PILATUS4 cadmium telluride detector and presents results from prototype testing for high-energy powder X-ray diffraction studies conducted at two synchrotrons. The experiments concern time-resolved in situ solid-state reactions at MAX IV (Sweden) and fast-scanning X-ray diffraction computed tomography of a battery cell at the ESRF (France). The detector's high quantum efficiency up to 100 keV, combined with a maximum frame rate of 4000 Hz, enables fast data collection. This study demonstrates how these capabilities contribute to improved time and spatial resolution in high-energy powder X-ray diffraction studies, facilitating advancements in materials, chemical and energy research.

MYTHEN III: advancements in single photon counting detectors for synchrotron powder diffraction experiments

The single photon counting microstrip detector MYTHEN III was developed at the Paul Scherrer Institute to satisfy the increasing demands in detector performance of synchrotron radiation experiments, focusing on time-resolved and on-edge powder diffraction measurements. Similar to MYTHEN II, the detector installed on the Material Science beamline covers 120° in 2θ. It is based on the MYTHEN III.0 readout chip wire-bonded to silicon strip sensors with a pitch of 50 µm, and it provides improved performance and features with respect to the previous version. Taking advantage of the three independent comparators of MYTHEN III, it is possible to obtain an improvement in the maximum count rate capability of the detector at 90% efficiency from 2.9 ± 0.8 Mphotons s-1 strip-1 to 11 ± 2 Mphotons s-1 strip-1 thanks to the detection of pile-up at high photon flux. The readout chip offers additional operation modes such as pump-probe and digital on-chip interpolation. The maximum frame rate is up to 360 kHz in 8-bit mode with dead-time-free readout. The minimum detectable energy of MYTHEN III is 4.3 ± 0.3 keV with a minimum equivalent noise charge (ENC) of 121 ± 8 electrons and a threshold dispersion below 33 ± 10 eV. The energy calibration is affected by temperature by less than 0.5% °C-1. This paper presents a comprehensive overview of the MYTHEN III detector system with performance benchmarks, and highlights the improvements reached in powder diffraction experiments compared with the previous detector generation.

Propagation of Orientation Across Lengthscales in Sheared Self-Assembling Hierarchical Suspensions via Rheo-PLI-SAXS

Simultaneous rheological, polarized light imaging, and small-angle X-ray scattering experiments (Rheo-PLI-SAXS) are developed, thereby providing unprecedented level of insight into the multiscale orientation of hierarchical systems in simple shear. Notably, it is observed that mesoscale alignment in the flow direction does not develop simultaneously across nano-micro lengthscales in sheared suspensions of rod-like chiral-nematic (meso) phase forming cellulose nanocrystals. Rather, with increasing shear rate, orientation is observed first at mesoscale and then extends to the nanoscale, with influencing factors being the aggregation state of the hierarchy and concentration. In biphasic systems, where an isotropic phase co-exists with self-assembled liquid crystalline mesophase domains, the onset of mesodomain alignment towards the flow direction can occur at shear rates nearing one decade before a progressive increase in preferential orientation at nanoscale is detected. If physical confinement prevents the full formation of a cholesteric phase, mesoscale orientation occurs in shear rate ranges that correspond to de-structuring at nanoscale. Interestingly, nano- and mesoscale orientations appear to converge only for biphasic suspensions with primary nanoparticles predominantly made up of individual crystallites and in a high-aspect ratio nematic-forming thin-wall nanotube system. The nano-micro orientation propagation is attributed to differences in the elongation and breakage of mesophase domains.

Visualising Geopolymerisation Processes Using Scanning X-Ray Diffraction and Fluorescence Microscopy

In situ observation of the dissolution of metakaolin followed by the condensation of geopolymer was performed by a combination of synchrotron X-ray fluorescence microscopy and scanning X-ray diffraction microscopy. New insight into the complex geopolymerisation process was obtained by simultaneously acquiring compositional and morphological information. The combination of selected alkali and experimental conditions produced a geopolymer with the targeted composition but resulted in the complete and rapid dissolution of metakaolin followed by immediate geopolymer formation. The geopolymer microstructure continued to evolve, along with pore growth, over several hours.

VMXm - A sub-micron focus macromolecular crystallography beamline at Diamond Light Source

VMXm joins the suite of operational macromolecular crystallography beamlines at Diamond Light Source. It has been designed to optimize rotation data collections from protein crystals less than 10 µm and down to below 1 µm in size. The beamline has a fully focused beam of 0.3 × 2.3 µm (vertical × horizontal) with a tuneable energy range (6-28 keV) and high flux (1.6 × 1012 photons s-1 at 12.5 keV). The crystals are housed within a vacuum chamber to minimize background scatter from air. Crystals are plunge-cooled on cryo-electron microscopy grids, allowing much of the liquid surrounding the crystals to be removed. These factors improve the signal-to-noise during data collection and the lifetime of the microcrystals can be prolonged by exploiting photoelectron escape. A novel in vacuo sample environment has been designed which also houses a scanning electron microscope to aid with sample visualization. This combination of features at VMXm allows measurements at the physical limits of X-ray crystallography on biomacromolecules to be explored and exploited.

Dynamic X-ray Coherent Diffraction Analysis: Bridging the Time Scales between Imaging and Photon Correlation Spectroscopy

The advent of diffraction limited sources and developments in detector technology opens up new possibilities for the study of materials in situ and operando. Coherent X-ray diffraction techniques such as coherent X-ray diffractive imaging (CXDI) and X-ray photon correlation spectroscopy (XPCS) are capable for this purpose and provide complementary information, although due to signal-to-noise requirements, their simultaneous demonstration has been limited. Here, we demonstrate a strategy for the simultaneous use of CXDI and XPCS to study in situ the Brownian motion of colloidal gold nanoparticles of 200 nm diameter suspended in a glycerol-water mixture. We visualize the process of agglomeration, examine the spatiotemporal space accessible with the combination of techniques, and demonstrate CXDI with 22 ms temporal resolution.

Multiplexing methods in dynamic protein crystallography

Time-resolved X-ray crystallography experiments were first performed in the 1980s, yet they remained a niche technique for decades. With the recent advent of X-ray free electron laser (XFEL) sources and serial crystallographic techniques, time-resolved crystallography has received renewed interest and has become more accessible to a wider user base. Despite this, time-resolved structures represent < 1 % of models deposited in the world-wide Protein Data Bank, indicating that the tools and techniques currently available require further development before such experiments can become truly routine. In this chapter, we demonstrate how applying data multiplexing to time-resolved crystallography can enhance the achievable time resolution at moderately intense monochromatic X-ray sources, ranging from synchrotrons to bench-top sources. We discuss the principles of multiplexing, where this technique may be advantageous, potential pitfalls, and experimental design considerations.

Real-time structural characterization of protein response to a caged compound by fast detector readout and high-brilliance synchrotron radiation

Protein dynamics are essential to biological function, and methods to determine such structural rearrangements constitute a frontier in structural biology. Synchrotron radiation can track real-time protein dynamics, but accessibility to dedicated high-flux single X-ray pulse time-resolved beamlines is scarce and protein targets amendable to such characterization are limited. These limitations can be alleviated by triggering the reaction by laser-induced activation of a caged compound and probing the structural dynamics by fast-readout detectors. In this work, we established time-resolved X-ray solution scattering (TR-XSS) at the CoSAXS beamline at the MAX IV Laboratory synchrotron. Laser-induced activation of caged ATP initiated phosphoryl transfer in the adenylate kinase (AdK) enzyme, and the reaction was monitored up to 50 ms with a 2-ms temporal resolution achieved by the detector readout. The time-resolved structural signal of the protein showed minimal radiation damage effects and excellent agreement to data collected by a single X-ray pulse approach.

Structure-property relationship of a complex photoluminescent arylacetylide-gold(I) compound. I: a pressure-induced phase transformation caught in the act

A pressure-induced triclinic-to-monoclinic phase transition has been caught `in the act' over a wider series of high-pressure synchrotron diffraction experiments conducted on a large, photoluminescent organo-gold(I) compound. Here, we describe the mechanism of this single-crystal-to-single-crystal phase transition, the onset of which occurs at ∼0.6 GPa, and we report a high-quality structure of the new monoclinic phase, refined using aspherical atomic scattering factors. Our case illustrates how conducting a fast series of diffraction experiments, enabled by modern equipment at synchrotron facilities, can lead to overestimation of the actual pressure of a phase transition due to slow transformation kinetics.

3D imaging of magnetic domains in Nd2Fe14B using scanning hard X-ray nanotomography

Nanoscale structural and electronic heterogeneities are prevalent in condensed matter physics. Investigating these heterogeneities in 3D has become an important task for understanding material properties. To provide a tool to unravel the connection between nanoscale heterogeneity and macroscopic emergent properties in magnetic materials, scanning transmission X-ray microscopy (STXM) is combined with X-ray magnetic circular dichroism. A vector tomography algorithm has been developed to reconstruct the full 3D magnetic vector field without any prior noise assumptions or knowledge about the sample. Two tomographic scans around the vertical axis are acquired on single-crystalline Nd2Fe14B pillars tilted at two different angles, with 2D STXM projections recorded using a focused 120 nm X-ray beam with left and right circular polarization. Image alignment and iterative registration have been implemented based on the 2D STXM projections for the two tilts. Dichroic projections obtained from difference images are used for the tomographic reconstruction to obtain the 3D magnetization distribution at the nanoscale.

Adaptive multi-beam X-ray ptychography

Ptychography has evolved as an important method for nanoscale X-ray imaging with synchrotron radiation. Recently, it has been proposed to work with multiple beams in parallel. The main advantage of so-called multi-beam ptychography is that larger areas can be imaged much faster than with a conventional single beam scan. We introduce adaptive multi-beam ptychography performed with two Fresnel zone plates, placed one behind the other. In contrast to previous demonstrations of multi-beam ptychography, our optical scheme allows for adapting the spatial beam separation to the needs of the sample under investigation, relaxes thickness requirements on zone plates and is straightforward to implement. Moreover, it is simple to switch between single and multi-beam illumination during the same experiment. This opens the possibility of combining large and fast overview scans with detailed imaging of certain regions of interests.

Recent advances in synchrotron scattering methods for probing the structure and dynamics of colloids

Recent progress in synchrotron based X-ray scattering methods applied to colloid science is reviewed. An important figure of merit of these techniques is that they enable in situ investigations of colloidal systems under the desired thermophysical and rheological conditions. An ensemble averaged simultaneous structural and dynamical information can be derived albeit in reciprocal space. Significant improvements in X-ray source brilliance and advances in detector technology have overcome some of the limitations in the past. Notably coherent X-ray scattering techniques have become more competitive and they provide complementary information to laboratory based real space methods. For a system with sufficient scattering contrast, size ranges from nm to several μm and time scales down to μs are now amenable to X-ray scattering investigations. A wide variety of sample environments can be combined with scattering experiments further enriching the science that could be pursued by means of advanced X-ray scattering instruments. Some of these recent progresses are illustrated via representative examples. To derive quantitative information from the scattering data, rigorous data analysis or modeling is required. Development of powerful computational tools including the use of artificial intelligence have become the emerging trend.

ForMAX - a beamline for multiscale and multimodal structural characterization of hierarchical materials

The ForMAX beamline at the MAX IV Laboratory provides multiscale and multimodal structural characterization of hierarchical materials in the nanometre to millimetre range by combining small- and wide-angle X-ray scattering with full-field microtomography. The modular design of the beamline is optimized for easy switching between different experimental modalities. The beamline has a special focus on the development of novel fibrous materials from forest resources, but it is also well suited for studies within, for example, food science and biomedical research.

xrdPlanner: exploring area detector geometries for powder diffraction and total scattering experiments

xrdPlanner is a software package designed to aid in the planning and preparation of powder X-ray diffraction and total scattering beam times at synchrotron facilities. Many modern beamlines provide a flexible experimental setup and may have several different detectors available. In combination with a range of available X-ray energies, it often makes it difficult for the user to explore the available parameter space relevant for a given experiment prior to the scheduled beam time. xrdPlanner was developed to provide a fast and straightforward tool that allows users to visualize the accessible part of reciprocal space of their experiment at a given combination of photon energy and detector geometry. To plan and communicate the necessary geometry not only saves time but also helps the beamline staff to prepare and accommodate for an experiment. The program is tailored toward powder X-ray diffraction and total scattering experiments but may also be useful for other experiments that rely on an area detector and for which detector placement and achievable momentum-transfer range are important experimental parameters.

Improvement of ultra-small-angle XPCS with the Extremely Brilliant Source

Recent technical developments and the performance of the X-ray photon correlation spectroscopy (XPCS) method over the ultra-small-angle range with the Extremely Brilliant Source (EBS) at the ESRF are described. With higher monochromatic coherent photon flux (∼1012 photons s-1) provided by the EBS and the availability of a fast pixel array detector (EIGER 500K detector operating at 23000 frames s-1), XPCS has become more competitive for probing faster dynamics in relatively dilute suspensions. One of the goals of the present development is to increase the user-friendliness of the method. This is achieved by means of a Python-based graphical user interface that enables online visualization and analysis of the processed data. The improved performance of XPCS on the Time-Resolved Ultra-Small-Angle X-ray Scattering instrument (ID02 beamline) is demonstrated using dilute model colloidal suspensions in several different applications.

Exploring high-throughput synchrotron X-Ray powder diffraction for the structural analysis of pharmaceuticals

Synchrotron radiation offers a host of advanced properties, surpassing conventional laboratory sources with its high brightness, tunable phonon energy, photon beam coherence for advanced X-ray imaging, and a structured time profile, ideal for capturing dynamic atomic and molecular processes. However, these benefits come at the cost of operational complexity and expenses. Three decades ago, synchrotron radiation facilities, while technically open to all scientists, primarily served a limited community. Despite substantial accessibility improvements over the past two decades, synchrotron measurements still do not qualify as routine analyses. The intrinsic complexity of synchrotron science means experiments are pursued only when no alternatives suffice. In recent years, strides have been made in technology transfer offices, intermediate synchrotron-based analytical service companies, and the development of high-throughput synchrotron systems at various facilities, reshaping the perception of synchrotron science. This article investigates the practical application of synchrotron X-Ray Powder Diffraction (s-XRPD) techniques in pharmaceutical analysis. By utilizing concrete examples, we demonstrate how high-throughput systems have the potential to revolutionize s-XRPD applications in the pharmaceutical industry, rapidly generating XRPD patterns of comparable or superior quality to those obtained in state-of-the-art laboratory XRPD, all in less than 5 s. Additional cases featuring well-established pharmaceutical active ingredients (API) and excipients substantiate the concept of high throughput in pharmaceuticals, affirming data quality through structural refinements aligned with literature-derived unit cell parameters. Synchrotron data need not always be state-of-the-art to compete with lab-XRPD data. The key lies in ensuring user-friendliness, reproducibility, accessibility, cost-effectiveness, and the streamlined efforts associated with synchrotron instrumentation to remain highly competitive with their laboratory counterparts.

Insight into structural biophysics from solution X-ray scattering

The current challenges of structural biophysics include determining the structure of large self-assembled complexes, resolving the structure of ensembles of complex structures and their mass fraction, and unraveling the dynamic pathways and mechanisms leading to the formation of complex structures from their subunits. Modern synchrotron solution X-ray scattering data enable simultaneous high-spatial and high-temporal structural data required to address the current challenges of structural biophysics. These data are complementary to crystallography, NMR, and cryo-TEM data. However, the analysis of solution scattering data is challenging; hence many different analysis tools, listed in the SAS Portal (http://smallangle.org/), were developed. In this review, we start by briefly summarizing classical X-ray scattering analyses providing insight into fundamental structural and interaction parameters. We then describe recent developments, integrating simulations, theory, and advanced X-ray scattering modeling, providing unique insights into the structure, energetics, and dynamics of self-assembled complexes. The structural information is essential for understanding the underlying physical chemistry principles leading to self-assembled supramolecular architectures and computational structural refinement.

ID22 - the high-resolution powder-diffraction beamline at ESRF

Following Phase 2 of the upgrade of the ESRF in which the storage ring was replaced by a new low-emittance ring along with many other facility upgrades, the status of ID22, the high-resolution powder-diffraction beamline, is described. The beamline has an in-vacuum undulator as source providing X-rays in the range 6-75 keV. ID22's principle characteristics include very high angular resolution as a result of the highly collimated and monochromatic beam, coupled with a 13-channel Si 111 multi-analyser stage between the sample and a Dectris Eiger2 X 2M-W CdTe pixel detector. The detector's axial resolution allows recorded 2θ values to be automatically corrected for the effects of axial divergence, resulting in narrower and more-symmetric peaks compared with the previous fixed-axial-slit arrangement. The axial acceptance can also be increased with increasing diffraction angle, thus simultaneously improving the statistical quality of high-angle data. A complementary Perkin Elmer XRD1611 medical-imaging detector is available for faster, lower-resolution data, often used at photon energies of 60-70 keV for pair-distribution function analysis, although this is also possible in high-resolution mode by scanning up to 120° 2θ at 35 keV. There are various sample environments, allowing sample temperatures from 4 K to 1600°C, a capillary cell for non-corrosive gas atmospheres in the range 0-100 bar, and a sample-changing robot that can accommodate 75 capillary samples compatible with the temperature range 80 K to 950°C.

Implication of the double-gating mode in a hybrid photon counting detector for measurements of transient heat conduction in GaAs/AlAs superlattice structures

Understanding and control of thermal transport in solids at the nanoscale are crucial in engineering and enhance the properties of a new generation of optoelectronic, thermoelectric and photonic devices. In this regard, semiconductor superlattice structures provide a unique platform to study phenomena associated with phonon propagations in solids such as heat conduction. Transient X-ray diffraction can directly probe atomic motions and therefore is among the rare techniques sensitive to phonon dynamics in condensed matter. Here, optically induced transient heat conduction in GaAs/AlAs superlattice structures is studied using the EIGER2 detector. Benchmark experiments have been performed at the Austrian SAXS beamline at Elettra-Sincrotrone Trieste operated in the hybrid filling mode. This work demonstrates that drifts of experimental conditions, such as synchrotron beam fluctuations, become less essential when utilizing the EIGER2 double-gating mode which results in a faster acquisition of high-quality data and facilitates data analysis and data interpretation.