Current Issue : October-December Volume : 2026 Issue Number : 4 Articles : 6 Articles
Context. Hard X-ray bremsstrahlung emissions are strong diagnostics of electron acceleration during the magnetic energy release process that drives solar flares. Solar Orbiter’s unique vantage point away from the Earth-Sun line allows us to use limb occultation as a diagnostic tool to investigate faint hard X-ray source located above the main flare site that are generally lost in the dynamic range of hard X-ray telescopes. Aims. We aim to highlight the feasibility and the diagnostic power of limb occultation with Solar Orbiter/STIX to quantify the intensity, spectral shape, and location of the occulted signals relative to the main flare emissions to investigate the energetic importance of nonthermal electrons in the high corona. Methods. We report on a single event study of the GOES M6 flare on October 19, 2024, simultaneously observed by ASOS/HXI, Fermi/GBM, and Solar Orbiter/STIX. We used standard X-ray spectral fitting tools available through OSPEX to compare the photon spectra observed by the three di erent observatories. In a second step, HXI and STIX X-ray images were compared to UV and EUV images seen by SDO/AIA to investigate the location of the occulted sources within the flare geometry. Results. From Earth’s perspective, the flare was seen on-disk near the west limb, while for STIX the flare is occulted by 19 degrees, allowing STIX to detect a much fainter thermal and nonthermal source in the high corona related to the coronal mass ejection (CME) associated with the flare. The nonthermal hard X-ray flux indicates that about 5% of flare-accelerated electrons are injected upward into the CME, assuming a thick target model, while the fraction increases for a partially thick target interpretation. The thermal source is hot (23:5 0:7 MK) and expands together with the CME. Even though the thermal source from the high corona has a weak bremsstrahlung signal, due to its large volume, its thermal energy content is on the same order of magnitude as the energy content in the main flare loops. Hence, hard X-ray sources associated with the escaping CME are an important signature of the energy release process. Conclusions. These observations highlight that high coronal sources are an integral part of solar eruptive events and are energetically important despite their intrinsically faint appearance. For future instrumentation, an emphasis should be put on high-dynamic-range imaging, such as that provided by hard X-ray focusing optics telescopes, to be able to simultaneously observe the flare and the high-coronal sources from a single vantage point observatory....
X-ray diffraction (XRD) combined with in situ mechanical testing is a powerful, non-destructive technique that provides valuable information on structural evolution and defect formation during deformation. Unlike many other characterization methods, XRD does not impose constraints on sample dimensions, does not require a vacuum environment, and can be applied to a wide range of materials with periodic structures. However, such experiments present significant challenges due to the need for precise synchronization between independently controlled systems: one managing mechanical loading and the other handling X-ray measurements. In this work, we report on the successful software- level integration of a nanoindenter control system directly into the beamline control system. This integration enables full control of both mechanical and diffraction measurements from a single user interface, allowing real-time synchronization and automation of complex in situ experiments. We demonstrate the capabilities of this setup through uniaxial compression tests on �-Ti micropillars. Mechanical data from the nanoindenter and XRD patterns were collected simultaneously in an automated mode. Raster scans were performed on the micropillar in its pristine state, at two intermediate deformation stages, and post-mortem. This approach enabled detailed analysis of mechanical behavior and structural evolution under load, illustrating the effectiveness of the integrated system for advanced in situ studies....
The integration of real‐time and flexible imaging has significantly advanced X‐ray scintillator imaging technologies. However, combining both functionalities into a single scintillator material remains a fundamental challenge. To address this, we designed a zero‐dimensional cerium (III)‐based organic‐inorganic hybrid halide scintillator, MPH2CeCl5·3H2O (MPH = morpholine), using low‐cost solution processing and leveraging Ce (III)'s inherently nanosecond‐scale 4f–5d transitions. La3+‐alloying induced a dual effect, enhancing the photoluminescence quantum yield to 2.75 times the original value while maintaining a short decay time of approximately 22 ns. Combined with heavy‐atom effects, this nanosecond‐scale decay prompted investigation of X‐ray scintillation performance, revealing a respectable light yield of 10,400 photons/MeV and a low detection limit of 96.73 nGyair/s. By embedding the optimized MPH2CeCl5·3H2O into poly(methyl methacrylate) (PMMA), we fabricated a highperformance flexible film that mitigates material hygroscopicity while enabling outstanding flexibility and dynamic imaging capabilities. This film achieved motion‐artifact‐free dynamic imaging at 100 fps, clearly resolving blades rotating at 560°/s. This work demonstrates Ce (III)‐based halide hybrids as promising platforms for advanced medical and industrial imaging, offering high light yield, rapid response, and superior processability....
We accelerate synchrotron X-ray reflectometry (XRR) by more than an order of magnitude and demonstrate the acquisition of full reflectivity curves within 213 ms over a qz range of 0.05 to 0.35 A ˚ 1 at 0.001 A ˚ 1 resolution. This is achieved by rapidly sweeping the incidence angle with a high-speed galvanometer and recording the reflected beam on an area detector. The method preserves a monochromatic parallel-beam geometry, requires only straightforward geometric and exposure time corrections, and yields quantitative agreement with standard XRR in thickness, density and roughness. At the shortest acquisition times, the photon statistics enter the low-count Poisson regime, where conventional least-squares fitting becomes biased. We show that applying an Anscombe variance-stabilizing transform restores near-Gaussian error behavior and significantly improves fitting robustness. Our approach benefits not only ultrafast XRR but reflectometry data in general at large qz, where count rates are intrinsically low. This advance enables time-resolved studies of thin-film growth, diffusion, photoswitching and other rapid kinetic processes....
Cutting inserts experience substantial mechanical and thermal loads during machining. Hard thin-film coatings are widely applied to enhance performance and durability, but their residual stresses critically affect adhesion, stability, and tool life. Common stress determination methods include X-ray diffraction (sin²ψ; Vm; XRD = 1.3–2.6 mm×3.7 μm), focused ion beam-digital image correlation (FIB-DIC) ring core method (Vm; FIB/DIC = 10 μm×3.7 μm), and Raman spectroscopy (Vm; Raman = 1 μm×40 nm), each deviating in measured volume (Vm = spot size × depth). Our comparative study examines different instrumentation, analysis tools, and applied methods for evaluating residual stresses in physical vapor deposition (PVD)-coated carbide inserts. Results disclose varying susceptibilities depending on thin film characteristics such as thickness, film-substrate interface, texture, chemical and residual stress gradients, highlighting differences in information depth and sensitivity. The study provides a good overview of laboratory methods for determining residual stresses in PVD coating. The sin²ψ-method provides reproducible residual stress states that are independent of varying instruments or analytical methods, including calibrants, radiation, different optics, detectors and even evaluated reflections and are more strongly affected by texture and residual stress gradient. FIB-DIC and sin²ψ method consider the entire cross-section and agree well. FIB-DIC offers higher spatial resolution and is more sensitive to nonuniform chemical influences. In Raman spectroscopy, the bond strength is affected by chemical gradients, among other factors, necessitating an elaborate calibration. Its low penetration depth of a few nanometers and the small spot size cause deviations in the studied heterogeneous thin films....
Pair distribution function (PDF) analysis based on X-ray total scattering is a powerful technique for elucidating local and medium-range structure in crystalline, nanocrystalline, and amorphous materials. Several software packages—such as GudrunX, PDFgetX2, and PDFgetX3—along with facility-specific programs developed at synchrotron sites, are widely used for this purpose. However, these tools typically require installation and environment-dependent configuration, which can introduce compatibility issues across operating systems and create conflicts with pre-installed software. To overcome these limitations, we developed a browser-based PDF analysis application implemented using Pyodide and PyScript, allowing it to run entirely in modern web browsers without additional installation. The software provides key functionalities, including Fourier transformation from S(Q) to G(r), calculation of g(r), back-Fourier transformation with cutoff handling, and sequential data processing. Demonstrations on representative samples confirm consistency with established programs. The software supports both synchrotron data and laboratory-based measurements using Ag radiation sources, underscoring its broad applicability. This tool enables environment-independent and consistent analyses, significantly enhancing the accessibility of X-ray total-scattering and PDF techniques....
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