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Short Communications articles in Journal of Synchrotron Radiation - rapid dissemination of novel and impactful results.
Not fully grasping the concepts of relativity can lead to misunderstandings about the fundamental background of synchrotron emission. Here we deal with some intriguing cases, in which the relevant `speed of light' is not the invariant c but the speed with respect to a moving object. This specifically affects two pillars of synchrotron radiation: the Lorentz length contraction and the Doppler shift. We propose a teaching strategy relying on new versions of simple `thought' experiments. Besides putting synchrotron radiation on solid foundations, the approach amazingly leads to a unique link-described by Einstein as `remarkable'-between special relativity and quantum mechanics.
A silicon carbide (SiC) X-ray beam position monitor is presented, based on a resistive charge-division principle derived from lateral-effect photodiodes and specifically adapted for synchrotron radiation applications. This device, referred to as a resistive X-ray beam position monitor (rXBPM), exploits a free-standing SiC membrane combined with a resistive p+-doped layer, enabling transmission-mode operation while preserving high radiation hardness and mechanical robustness. In contrast to conventional segmented X-ray beam position monitors, whose response depends strongly on the beam spot size and is typically limited to narrow linear regions, the resistive architecture of the rXBPM provides an intrinsically beam-footprint-independent position signal with an extended linear response region. The detector was fabricated using selective electrochemical etching to realize a thin membrane structure and was experimentally characterized at the microfocus beamline (MiFo) in the PTB laboratory at the BESSY II synchrotron facility using 5.4 keV X-rays. An average transmission of approximately 61% was measured, with good spatial uniformity across the membrane area. Raster-scan measurements demonstrate a linear position response over ranges of ±500 µm and ±1 mm around the detector center, with position sensitivities exceeding 0.157 mm-1 and estimated upper-limit noise-equivalent positions of a few micrometres. Three-dimensional COMSOL simulations were used to model charge transport and lateral charge division in the real device geometry, showing excellent agreement with experimental results and confirming the independence of the position sensitivity from the beam spot size over a wide range of operating conditions. These results establish SiC rXBPMs as a compact, beam spot size calibration-free and radiation-hard solution for beam diagnostics at modern synchrotron light sources, with particular relevance for applications requiring large active areas, extended linearity and minimal beam perturbation.
In the context of the global big data deluge, concerted efforts are being made to address the challenges faced by large scientific facilities. These efforts are focused on providing users with the full potential offered by real-time, remote and self-driving experiments, where AI-driven analysis can guide experimental decisions in real time, while ensuring that the data pipelines adhere to the findability, accessibility, interoperability and reuse principles throughout their entire facility lifecycle. Besides all the efforts being made, a user-centric and user-friendly centralization of the overall scientific computing framework at the large scientific facilities remains a work in progress. To address this challenge the Big Data Science Center at the Shanghai Synchrotron Radiation Facility has developed and deployed a centralized, cohesive and user-friendly platform on top of its already existing superfacility framework, which is designed to manage the complete data lifecycle at large scientific facilities. This user-centric platform has transformed the user experience, shifting focus from complex data operations to scientific interpretation. Consequently, the accessibility of the facility to users has been considerably enhanced, thereby expediting the pace at which their discoveries are made.
A magnetic field modulation-based scheme for fast polarization switching of undulator radiation has been proposed for Hefei Advanced Light Facility (HALF), a fourth generation soft X-ray light source based on a diffraction-limited storage ring. In this scheme, two undulators with opposite helicities are employed, each equipped with electromagnetic coils placed on the upper and lower surfaces of the vacuum chamber. Through fast switching the power of the coils, the radiation frequencies of two undulators can be rapidly shifted into and out of the band pass of a monochromator; polarization switching at the kHz level in the photon energy range 330-1000 eV for user beamlines can be expected with a stainless steel vacuum chamber. Crucially, a vacuum chamber designed for HALF is selected to be used for the simulations, representing the first demonstration of achieving such switching frequency under realistic vacuum chamber conditions. The limitations imposed by chamber-induced eddy currents have been studied. Benefiting from the low current and compact coil size, polarization switching at approximately 100 Hz can still be achieved even with an aluminium or copper vacuum chamber. Numerical simulations confirm the feasibility of the scheme, demonstrating high polarization degree and maintained high photon flux. Furthermore, these coils are designed to correct the first and second integrals of magnetic field themselves. This method can also be easily adopted for other light sources requiring fast polarization control.
This study explores the use of advanced synchrotron radiation (SR)-based imaging and spectroscopic techniques to investigate the distribution and nature of mercury (Hg) in numismatic artifacts, with a particular focus on its role in historical counterfeiting practices. A selection of medieval silver coins exhibiting anomalous surface Hg signals, initially identified through portable energy-dispersive X-ray fluorescence (ED-XRF) and laser-induced breakdown spectroscopy, were further examined using high-resolution synchrotron X-ray micro-computed tomography (SR-µCT), micro-X-ray spectroscopy (SR-µXRF) and micro-X-ray diffraction (SR-µXRD) at the PSICHÉ beamline of the SOLEIL Synchrotron. Comparative analyses were conducted on coins produced by an unofficial mint at the Castle of Godano (La Spezia, Italy) and on verified genuine specimens. The results provide evidence for the use of Hg-Ag amalgam, indicative of fraudulent minting practices. This research highlights the methodological strength of integrating multiple non-destructive techniques. Portable ED-XRF demonstrates significant utility as a preliminary screening tool for detecting Hg in medieval and Renaissance coins, supporting the identification of potential forgeries. The combined use of SR-µCT, SR-µXRF and SR-µXRD offers a comprehensive framework for probing internal microstructures and elemental compositions of metal archaeological objects, advancing our understanding of both ancient coinage and fraudulent processes.
Experiment proposals at synchrotron facilities serve as the primary gateway for instrument access. They currently lack the standardized and granular topic metadata necessary for tasks such as classification and review, and, broadly speaking, reuse. This paper defines and tests the feasibility of a real-time topic classification service for experiment proposals using an open-source machine-learning model and domain experts for the evaluation phase. We applied the OpenAlex topic classification model to 5384 experiment proposals and selected 209 of them to each be independently evaluated by three domain experts to assess the performance and utility of the model. Analysis of the evaluations reveals a general consensus among the reviewers regarding the model's predictions, with a Krippendorff's alpha of 0.572. We also find that 74.2% of the proposals had at least one topic that was unanimously deemed relevant, which suggests that the model performs well enough to be used in a live setting with real-time verification. However, we do not recommend using it in automated environments without human oversight, given the proposal-based precision score of 56.0%. By aligning the data infrastructure of photon and neutron facilities with the OpenAlex ecosystem, we also lay the groundwork for the eventual inclusion of proposals and experiment reports into OpenAlex, which is necessary for a complete record of a research activity.
Hierarchical phase-contrast tomography (HiP-CT) was recently developed to enable the ex vivo imaging of human organs at multiple scales from whole organ down to near-cellular resolution in localized regions. Using whole adult human brain imaging as a case study, this article shows the evolution and optimization of this technique from its initial development at the BM05 beamline to its transition and current status at BM18. Thanks to the higher spatial coherence, larger beam size, higher energies and larger propagation distances available at BM18 and due to the European Synchrotron's Extremely Brilliant Source upgrade (ESRF-EBS), this transition resulted in significantly improved data quality, resolution, sensitivity and speed. More recently, the implementation of a new generation of larger sCMOS cameras, helical scanning (including dedicated reconstruction algorithm developments), binning at the chip and projections levels, and the design of high-efficiency optics allowed us to progressively improve the trade-off between dose and image quality, and acquisition time. These advances enable whole-organ imaging at voxel sizes ranging from ∼42 µm to ∼15 µm, with acquisition times reduced from ∼18 h to ∼3-6 h, depending on configuration. These acquisition schemes present the current status of full-organ imaging using HiP-CT and represent the constant efforts for improvement of the technique towards the investigation of human organs in health, disease and ageing.
A surface-enhanced Raman scattering (SERS) sensor built on a free-standing Au/Cu-covalent organic framework (COF) membrane was developed for the noninvasive Helicobacter pylori detection by quantifying trace ammonia in exhaled breath. The porphyrin-based Cu-COF acts as a multifunctional sensing interface, using its porous structure and accessible porphyrin-Cu coordination sites to efficiently capture and preconcentrate ammonia vapor. The change of intensity of the characteristic SERS peak at the 391 cm-1 Raman peak (ΔI391) shows a good linear relationship with ammonia concentration in the range of 0.5 to 3 ppm, with a limit of detection (LOD) down to 0.5 ppm. The sensor shows good stability and anti-interference ability toward common volatile organic compounds (VOCs) and inorganic gases in breath, allowing rapid detection without complex sample pretreatment. Notably, the introduction of Cu2+ significantly enhanced the crystallinity and structure ordering of the COF membrane, offering a new strategy for metal-ion-mediated structural regulation of 2D COF films. Preliminary clinical blind testing on exhaled breath samples yields a 70% diagnostic accuracy for H. pylori infection, validating the practical potential of this sensor. This work establishes a robust SERS platform for breath biomarker analysis and provides a promising route for noninvasive, real-time, and point-of-care diagnosis of H. pylori infection.
Reliable monitoring of the incident X-ray beam intensity and position is essential in soft X-ray microspectroscopy, where beam instabilities directly affect data normalization and achievable spatial resolution. Conventional beam diagnostics are often implemented using offline detectors located far from the sample or by measuring downstream on empty regions of the sample support membrane, not fully reflecting the experimental conditions experienced during measurements. In this work, the development of functionalized soft X-ray optical elements based on monolithic silicon carbide (SiC) diode detectors, enabling real-time in situ beam diagnostics directly within a scanning transmission X-ray microscopy (STXM) setup, is presented. Two complementary device geometries are investigated: order-sorting aperture (OSA)-based detectors and center-stop-based detectors. The devices are fabricated using plasma-focused-ion-beam milling and substrate thinning, allowing the integration of optical and sensing functionalities with minimal changes to the beamline and endstation setup. The performance of the functionalized optics is experimentally validated at the PolLux STXM beamline of the Swiss Light Source. The devices provide simultaneous access to the transverse beam position and the incident beam intensity I0 through the unfocused 0th-order component. Using this component, the OSA detector enabled simultaneous measurements of the intensity and transverse displacement of the beam from the focused beam illuminating the sample. Between 700 and 1000 eV, the SiC measured current exhibited linear correlation to the avalanche photodiode (APD) signal, with coefficient of determination R2 = 0.997. Position-sensitive detection was possible with a four-sector diode, where all sectors were electrically continuous and beam responsive, while gaps between the quadrants were insensitive. These results demonstrate the feasibility of SiC-based functionalized X-ray optics as beam diagnostic tools for soft X-ray microscopy and spectroscopy.
FLASH radiotherapy involves delivering relatively high radiation doses at ultra-high dose rates (UHDRs) that are several orders of magnitude greater than those used in conventional radiotherapy (40 Gy s-1 versus 0.5-5 Gy min-1, respectively). Previous in vivo studies have shown that doses delivered with such UHDRs result in significant tumour killing while having less effect on normal tissues. Most of these in vivo studies were based on the use of charged particles such as electrons and protons. In this study we exposed cells [human epidermal melanocytes (HEM), MM96L melanoma cells, CCD841 colon epithelial cells and CaCo2 colorectal adenocarcinoma cells] grown in vitro to synchrotron-based X-ray beams delivered at either low dose rates or UHDRs to validate the FLASH effect. The FLASH effect that has been reported to occur under hypoxic conditions was also investigated using HEM and MM96L cells. Significant cell killing was observed at 48 h post-irradiation, when the cells were exposed to high dose (≥10 Gy) UHDRs compared with low dose rate beams in both groups of cells. MM96L melanoma cells were ∼10% less resistant to UHDR than were HEM cells. A similar result was observed in CCD841 and CaCo2 cells. When the hypoxic melanocytes were exposed to (≥10 Gy) UHDRs a minimal loss of cell viability was observed; however, when hypoxic MM96L cells were irradiated, significant cell losses were observed. These results show that a FLASH effect is evident in these skin and colon cells. Moreover, when MM96L melanoma cells were pretreated with 1 mM gold nanoparticles and exposed to 10 Gy UHDR X-rays there was a 50% dose enhancement observed where only 15% was observed at low dose rates.
The reaction kinetics and structure of alkali-activated binders are known to be affected by their calcium (Ca) contents. However, the intrinsic difference between high Ca and low Ca alkali-activated systems, especially at the atomic scale, has not been fully investigated. Here, we compare local atomic ordering and reaction kinetics of blast furnace slag and metakaolin as representatives of high and low Ca systems, respectively. In situ X-ray pair distribution function (PDF) analysis and isothermal calorimetry were utilized in parallel to investigate the evolution of local structure in these systems. Isothermal calorimetry results showed contrasting reaction kinetics of high Ca (alkali-activated slag) and low Ca (alkali-activated metakaolin) systems, where the latter shows no induction period. The evolution of specific PDF peaks is related to the main binder gels in each respective system and can be used to track their reaction kinetics, exhibiting excellent correlation with the cumulative heat data (R2 > 0.97). Finally, and most importantly, the PDF results revealed that the atomic ordering of N-A-S-(H) gel is limited up to ∼10 Å, whereas C-(N)-A-S-H gel grew up to ∼40 Å, which suggests that there is an intrinsic difference in the formation mechanism and local structures of dominant gels formed in high and low Ca systems.
Here, we review the capabilities of beamline I16 at Diamond Light Source after nearly 20 years of operation and continuous development. I16 is an X-ray scattering beamline operating in the 2.46-16 keV energy range with energy scans with a resolution of 1 meV. The beamline is equipped with a six-circle kappa diffractometer, offering flexible experimental geometries and support for a variety of ancillary equipment. Available equipment includes cryostats and cryofurnaces that span temperatures from 4.2 K to 700 K, which can be combined with applied electric fields, permanent magnets up to 1 T, and uniaxial strain cells. A range of detectors is mounted on the diffractometer arm, including a photon-counting area detector and an avalanche photodiode, both compatible with crystal analyzers for polarization analysis. Diamond single-crystal phase retarders provide full control of the incident X-ray polarization. These capabilities establish I16 as a state-of-the-art instrument for resonant and non-resonant X-ray scattering, multi Bragg coherent diffraction imaging, and grazing-incidence small- and wide-angle X-ray scattering. Together, they allow for studies of complex electronic, magnetic and structural phenomena in single crystals and thin films. We also outline the software infrastructure supporting experiment planning, data acquisition and rapid on-the-fly data analysis, and discuss ongoing developments and the anticipated benefits of the upgrade to a fourth-generation source.
X-ray spectrometers with high count rate capability are becoming essential to provide higher speeds in synchrotron measurements, like in X-ray fluorescence mapping (XFM). Monolithic multichannel silicon drift detectors (SDDs) enable the creation of dense and high-performance matrices to reach this goal. In this paper we show the results of the development of ASCANIO, a 16-channel backscattering X-ray spectrometer based on SDD monolithic modules. The solid angle and count-rate uniformity in X-ray detection have been optimized thanks to a `tilted' configuration of the SDD units. ASCANIO underwent preliminary testing in the laboratory, where the system achieved around -42°C with an internal pressure of 5.1 × 10-6 mbar. During further verification of its spectroscopic performance, the spectrometer showed resolutions as low as 134 eV FWHM at the Mn Kα peak. After preliminary testing the full system was commissioned on beamline P06 at PETRA III (DESY). Here the effects of the tilted configuration could be observed, and the system achieved a 20 Mcps cumulative output count rate with a dead time of 20%. As a demonstration of ASCANIO's usability, an example use case is demonstrated, where ASCANIO was used for an XFM analysis of a biological sample.
The development of fourth-generation synchrotrons, including the Diamond-II upgrade, promises 10-100× flux increases, reaching up to 1012 photons s-1 mm-2 at the detector, across a broad range of energies from 20 to 100 keV. To exploit fully these impressive photon fluxes and high X-ray energies, readout chips must achieve high frame rates and dynamic ranges, while the use of high-Z sensor materials is essential. To address these challenges, the UK's Science and Technology Facilities Council has developed DynamiX, a test structure for a novel two-stage charge cancellation circuit on a 65 nm CMOS process with a dynamic range from single photon(s) per pixel per frame to >9000 photons per pixel per frame (1011-1012 photons s-1 mm-2) at 20 keV photon energy. The application-specific integrated circuit has 16 ×16 pixels on 110 µm pitch and is hybridized with 2 mm thick Redlen high-flux cadmium zinc telluride (HF-CdZnTe). Data are read out at 534000 frames per second over a 14 Gbps serialiser and frames are assembled and saved with a custom data acquisition system. Measurements were made on the Diamond Light Source (DLS) B16 Test Beamline using monochromatic X-ray beams of different sizes and energies to evaluate the detector performance. A sub-pixel beam of size ∼60 µm × ∼15 µm was used to probe pixels to measure single photons with a noise performance of σ = 5.7 ± 0.1 keV. These single photons are used to calibrate the test pulse and pixel cancellation packet sizes. The linearity of the detector response under increasing flux was measured from <1 photon per pixel per frame to ∼109 photons s-1 mm-2 at 20 keV with an r.m.s. linearity of 6.2%. A polychromatic X-ray set was used to reach higher fluxes of ∼3 × 1010 photons s-1 mm-2 (20 keV equivalent), yielding an r.m.s. linearity of 3.2%. Finally, the full sensor area was used to image a rotating slitted disc at 534000 frames per second.
Powder X-ray diffraction (PXRD) and X-ray absorption near-edge structure (XANES) spectroscopy are complementary techniques for probing cobalt-based (Co-based) Fischer-Tropsch synthesis (FTS) catalyst structures. PXRD reveals crystalline composition, while XANES provides information on coordination geometry and oxidation state. We developed a fast, automated measurement method, based on rapid selection of X-ray beam energy and a dedicated sample environment at beamline ID10 (ESRF), to combine in situ PXRD and XANES in a single experiment. This approach enables simultaneous monitoring of structural and electronic changes in Co-based FTS catalysts under in situ conditions up to 60 bar, offering a comprehensive view of catalyst dynamics.
Diamond is extremely well suited for synchrotron X-ray refractive optics. The effectiveness of diamond refractive lenses, fabricated by pulsed laser ablation, is demonstrated here for the focusing, collimation, and expansion of high-energy, undulator-source X-ray beams in the 40-70 keV photon energy range. The design of the lens elements and their mounting scheme allow the convenient feature of stacking both one-dimensionally and two-dimensionally focusing elements together in a self-aligning manner within the same holder for astigmatic manipulation, when needed. The CuCrZr alloy frames embedding the diamonds are suitable for thermal management, while possessing hardness. Collimating lenses, placed following a high-heat-load monochromator, are employed to increase the throughput of a subsequent narrow-angular-acceptance high-energy-resolution monochromator, after which the X-rays are focused to deliver a beam to coherent diffraction experiments on a long beamline. Also motivated and proposed is the concept of a convex beam-expander, which might seem counterintuitive given that it has higher attenuation on-axis. However, for high-energy X-rays from a low-emittance source on a long beamline, convex diamond beam-expanders could be practical. A proof-of-principle test result of this idea is presented.
Steroid hormone testing is critical for assessing endocrine function, diagnosing related disorders, and monitoring therapeutic efficacy. However, current mainstream detection methods have limitations. Although liquid chromatography-tandem mass spectrometry (LC-MS/MS), regarded as the gold standard, offers high sensitivity and specificity, it involves complex and time-consuming procedures. Immunoassays such as enzyme-linked immunosorbent assay (ELISA) are simple and fast but are limited by poor throughput for multitarget detection. Therefore, it is crucial to develop an analytical method that streamlines procedures and enables efficient parallel detection of multiple targets. We developed an integrated signal-enhanced aptasensor platform for pooled MS detection of three steroid hormones in serum. It combines aptamer recognition with mass-tag amplification. This approach uses biorecognition instead of chromatography, while mass spectrometry enables simultaneous readout of multiple mass tags from combined samples. The method was evaluated by detecting three steroid hormones (vitamin D, cortisol, and testosterone) in simulated serum samples and human serum samples. The limits of detection (LODs) for these analytes ranged from 0.411 to 6.796 nM, which are below the established clinical cut-off values for each steroid, demonstrating the requisite sensitivity for detection. This integrated signal-enhanced aptasensor outperforms conventional LC-MS/MS in efficiency and ELISA in throughput, enabling the quantification of multiple serum steroid hormones. Therefore, we believe that this method could be potentially useful in the clinical screening of hormone-related disorders and suitable for the analysis of serum.
The study of the mechanical behaviour of carbonate rocks has benefited from the evolution of experimental tools, due to their complex multi-scale microstructure. Triaxial cells transparent to X-rays have emerged and allowed in situ investigation of progressive failure developments and their link with microstructure. We conducted a series of 4D X-ray computed tomography mechanical tests on porous Saint-Maximin limestone at the PSICHE beamline of Synchrotron SOLEIL. Tests were performed using an in-house-developed triaxial press, Modulo. Volumes were scanned using a helical acquisition and reconstructed at 2.83 µm. They were then analysed using digital volume correlation. Volumetric strain and shear strain magnitude maps were computed using a 100 voxels gauge length with Paraview. Additionally, we computed porosity maps based on mean grey levels, at the same gauge length. Analysis of total and normalized incremental strain maps was carried out. We also compared volumetric strain maps with the initial porosity maps. Each step of the procedure is described herein. The errors on strain and porosity are discussed.
Commissioning of a synchrotron hard X-ray nanoprobe beamline traditionally requires months of iterative alignment after hardware installation, during which operational knowledge accumulates but remains inaccessible to non-specialist users. To address this, we present a browser-based virtual commissioning platform for the Korea Light Source ID10 Hard X-ray Nanoprobe beamline (first light 2029) that allows beamline scientists to design, test and refine alignment procedures, scan plans and experimental workflows years before the first photon arrives. Specifically, the platform integrates a Monte Carlo ray-tracing engine, a standard Experimental Physics and Industrial Control System (EPICS)/Bluesky control stack, and a multilingual natural-language interface within a single deployable package, which we name HANBIT (Hybrid Agent-driven Natural-language Beamline Interactive Toolkit). Users can interactively explore parameter trade-offs, such as the effect of the secondary source aperture on beam size versus photon flux. The Monte Carlo engine reproduces the overall Shadow4 beam-profile shape and is validated against SPECTRA undulator spectra, source size and divergence. The natural language processing (NLP) agent achieves 98.2% automated action-identification accuracy across 228 test cases in Korean, English and Japanese, whereas expert review of the same responses yields an acceptance rate of 67.3%. We identify this 30.9 percentage-point gap as a central finding: automated accuracy does not guarantee operational acceptability, and closing it is the key challenge for deployment-grade natural-language beamline control. We further validate the zero-change hardware transition strategy that the beamline pursues on three real hardware subsystems, confirming that at the validated device layers the control code and scan plans operate unchanged on the real devices; the integration of the remaining parts, such as high-rate area detectors, which awaits the detector hardware, is also discussed.