Journal of Applied Crystallography最新文献

{"title":"EQSANS-CLI: a natural-language agent-ready command-line tool for small-angle neutron scattering data reduction at EQ-SANS","authors":"Changwoo Do","doi":"10.1107/S160057672600600X","DOIUrl":"https://doi.org/10.1107/S160057672600600X","url":null,"abstract":"<p>Small-angle neutron scattering data reduction at user facilities follows a largely repetitive workflow. Runs are first classified in the catalog and matched to transmission, background and empty-beam references within the same instrument configuration. The data are then reduced, placed on an absolute scale using a standard and stitched across configurations. Although these steps are individually well understood, they remain weakly connected, producing a coordination burden that scales with the number of runs and configurations. This paper describes <i>EQSANS-CLI</i>, a command-line interface (CLI) that organizes this workflow into a coherent, scriptable and agent-addressable system. The design rests on four principles: a shared command-handler layer that all input paths converge on; a persistent working table that holds every reduction decision as editable rows; two input surfaces (an interactive terminal and a headless JSON mode) that compile to the same handler entry point; and a status-driven re-reduction model that treats parameter changes as first-class events. An <span>/autopilot</span> command chains the full pipeline from the proposal number to stitched <i>I</i>(<i>Q</i>) curves in one invocation. A Slack bot was used to demonstrate that the headless interface, together with a single skill document loaded into an external agent's system prompt, is sufficient to drive complete reductions by natural language from a mobile device. Slack is a commercial team-messaging platform widely used at Oak Ridge National Laboratory, but the agent pattern itself is channel independent. The architecture is intentionally minimal on the agent side: the CLI is the authoritative executor, and the agent's only job is to translate human intent into commands on a stable contract.</p>","PeriodicalId":48737,"journal":{"name":"Journal of Applied Crystallography","volume":"59 5","pages":"1364-1373"},"PeriodicalIF":2.7,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149099723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Initial characterization of a prototype target–moderator–reflector assembly for an electron-driven compact accelerator-driven neutron source at CERN's CLEAR facility","authors":"Laurence Wroe,&nbsp;Roberto Corsini,&nbsp;Wilfrid Farabolini,&nbsp;Davide Gamba,&nbsp;Torsten Koettig,&nbsp;Steinar Stapnes,&nbsp;Fares Elattab,&nbsp;Giorgi Kharashvili,&nbsp;Francois Plewinski,&nbsp;Federico Vanti,&nbsp;Jonas Okkels Birk","doi":"10.1107/S1600576726005224","DOIUrl":"https://doi.org/10.1107/S1600576726005224","url":null,"abstract":"<p>The Versatile ULtra-Compact Accelerator-based Neutron source (VULCAN) project is developing a compact accelerator-driven neutron source optimized for neutron diffractometry in industrial and university settings. Central to VULCAN is a novel target–moderator–reflector (TMR) assembly optimized to convert a 35 MeV pulsed electron beam into short neutron pulses (FWHM ≤ 20 µs) in the 1.5–3.5 Å wavelength range. To validate the simulation-driven design process, a prototype TMR was developed for testing at CERN's CLEAR facility, and this paper presents the design, installation and results of the first experimental campaign. While moderated neutron pulses were successfully detected, significant discrepancies were observed between the experimental and simulated energy spectra. Potential causes are discussed and recommendations for follow-up measurements are provided.</p>","PeriodicalId":48737,"journal":{"name":"Journal of Applied Crystallography","volume":"59 5","pages":"1500-1508"},"PeriodicalIF":2.7,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149099840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Anisotropic extension of the Parratt formalism","authors":"Szilárd Sajti,&nbsp;László Deák","doi":"10.1107/S1600576726006540","DOIUrl":"https://doi.org/10.1107/S1600576726006540","url":null,"abstract":"<p>Neutron and X-ray reflectometry are widely used for investigating thin multilayer structures. Numerical modeling of such systems is commonly performed using the Parratt formalism or the method of characteristic (transfer) matrices. The conventional Parratt method was originally formulated for isotropic media, whereas the transfer-matrix approach can treat anisotropic (magnetic) systems but is prone to numerical instabilities, particularly for multilayers with a large number of periods, where the total thickness becomes large under grazing-incidence conditions. In this work, a generalized Parratt formalism applicable to anisotropic layered systems is derived. Explicit expressions are obtained for both reflectivity and transmissivity. A simulation and data-analysis program implementing the new formalism has been developed and used to perform numerical studies of representative multilayer structures. Direct comparisons with transfer-matrix calculations demonstrate the improved numerical stability of the generalized Parratt approach. A mathematical analysis clarifies the origin of the instabilities inherent in the transfer-matrix formulation. The treatment of rough interfaces is also discussed, and several commonly used approximations are compared.</p>","PeriodicalId":48737,"journal":{"name":"Journal of Applied Crystallography","volume":"59 5","pages":"1393-1406"},"PeriodicalIF":2.7,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149099842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Commissioning of a versatile grazing-incidence platform at a very small angle neutron scattering instrument for investigating nano-to-microscopic colloidal assembly","authors":"Qing Chen,&nbsp;Taisen Zuo,&nbsp;Changli Ma,&nbsp;Yongcheng He,&nbsp;Xiong Lin,&nbsp;Zhenqiang He,&nbsp;Zehua Han,&nbsp;Peter Müller-Buschbaum,&nbsp;He Cheng","doi":"10.1107/S1600576726008022","DOIUrl":"https://doi.org/10.1107/S1600576726008022","url":null,"abstract":"<p>Grazing-incidence small-angle neutron scattering (GISANS) is a powerful technique for probing buried interfacial structures, yet its in-plane length-scale sensitivity is typically limited to a few hundred nanometres. Here, we report the successful commissioning of a standard GISANS and a novel grazing-incidence very small angle neutron scattering (GI-VSANS) setup at the China Spallation Neutron Source (CSNS), which extends the accessible in-plane length scale of conventional GISANS to several micrometres. This breakthrough establishes GI-VSANS as an essential complementary tool to standard GISANS for investigating hierarchical and microscopic structures at thin film interfaces. To overcome the challenges of low neutron flux and high sensitivity to the alignment of sample planes, which are inherent to VSANS instruments, we developed and implemented an apparatus that integrates a four-blade slit system and a multi-slit collimation array for precise beam focusing over the sample plane. We demonstrate the capability of this platform by resolving the in-plane size, distribution and hierarchical assembly patterns of colloids with diameters ranging from the nano- to submicrometre scale, and prepared from different coating methods. Based on this platform, colloidal assembly patterns are resolved at the nanoscale (by the GISANS configuration) and the microscale (by the GI-VSANS configuration) through quantitative analysis. The successful commissioning and validation of this user-friendly, modular GI-VSANS setup not only overcome significant instrumental challenges but also provide users at spallation neutron sources with a unique tool for probing previously inaccessible microscale in-plane interfacial structure.</p>","PeriodicalId":48737,"journal":{"name":"Journal of Applied Crystallography","volume":"59 5","pages":"1517-1530"},"PeriodicalIF":2.7,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149100504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A unified resolution and multiple-scattering correction framework for Spallation Neutron Source ultra-small-angle neutron scattering and complementary small-angle neutron scattering","authors":"Chi-Huan Tung,&nbsp;Guan-Rong Huang,&nbsp;Yangyang Wang,&nbsp;Jan-Michael Carrillo,&nbsp;Tao Zhang,&nbsp;Yuya Shinohara,&nbsp;Gernot Rother,&nbsp;Yingrui Shang,&nbsp;Christopher Neal,&nbsp;Luke Heroux,&nbsp;Changwoo Do,&nbsp;Wei-Ren Chen","doi":"10.1107/S1600576726007570","DOIUrl":"https://doi.org/10.1107/S1600576726007570","url":null,"abstract":"<p>Ultra-small-angle neutron scattering (USANS) measurements at the Spallation Neutron Source (SNS) at Oak Ridge require careful treatment of slit-geometry resolution effects and, in many cases, multiple scattering in complementary small-angle neutron scattering (SANS) data before meaningful structural interpretation can be made. We present a unified data-reduction framework that provides SNS USANS users with a systematic and reproducible workflow for obtaining intrinsic single-scattering intensities across the combined USANS–SANS <i>Q</i> range. The approach explicitly formulates the slit-geometry point-spread function for Bonse–Hart USANS, implements both analytical truncated Abel inversion and Bayesian Gaussian process regression for stable desmearing with uncertainty quantification, incorporates central-moment expansion for pinhole SANS resolution correction, and applies an orthonormal spectral method for probabilistic multiple-scattering removal. The ordered workflow ensures that instrumental resolution and multiple-scattering distortions are removed consistently prior to merging datasets, so that the resulting spectrum represents a physically meaningful resolution-free cross section. Experimental demonstrations on isotropic systems, uniaxially stretched materials and shear-induced anisotropic configurations illustrate both the applicability and the geometric limitations of anisotropic desmearing. This framework provides practical guidance for reliable SNS USANS data reduction and establishes a resolution-consistent foundation for quantitative structural analysis from nanometre to micrometre length scales.</p>","PeriodicalId":48737,"journal":{"name":"Journal of Applied Crystallography","volume":"59 5","pages":"1454-1466"},"PeriodicalIF":2.7,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149099609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Isopoints in small-angle scattering. I. Form factors of inhomogeneous quasi-spherical particles under contrast variation","authors":"Mikhail V. Avdeev","doi":"10.1107/S1600576726007417","DOIUrl":"https://doi.org/10.1107/S1600576726007417","url":null,"abstract":"<p>A general analysis of the problem of observing isoscattering points (isopoints) in the form factors of inhomogeneous quasi-spherical particles under contrast variation in a small-angle scattering experiment is presented. The approach of basic functions is applied with the extension of the criteria for observing pure isopoints to the practical area by considering experimental isopoints as caustic-type nodes with a concentration of curves. This approach allows one to follow in a universal way the influence of different factors on isopoints, such as experimental resolution, residual background, particle polydispersity and shape anisotropy. The identification of isopoints in relation to their possible types and related phenomena, including shifts, smearing and disappearance of isopoints, is discussed. All this makes it possible to predict and analyze for concrete models (first of all, of the `core–shell' types) the practical intervals over contrast and momentum transfer in which isopoints can be experimentally observed, and how strongly they are smeared. An overview of experimental (small-angle X-ray and neutron scattering, and static light scattering) observations of isopoints for scattering form factors is given and discussed in the light of the proposed approach. Finally, the possibilities and challenges for the extended use of the isopoint effect to obtain additional information about the systems under study are outlined.</p>","PeriodicalId":48737,"journal":{"name":"Journal of Applied Crystallography","volume":"59 5","pages":"1432-1453"},"PeriodicalIF":2.7,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149100544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"How a high rotational barrier enables packing-controlled stabilization of a conformational quasi-enantiomer","authors":"Sławomir Frynas,&nbsp;Oleg M. Demchuk,&nbsp;Daniel Kamiński","doi":"10.1107/S1600576726006618","DOIUrl":"https://doi.org/10.1107/S1600576726006618","url":null,"abstract":"<p>Variable-temperature NMR (VT-NMR) spectroscopy was employed to investigate the rotational dynamics of (1,4-diacetoxy-3-methylnaphth-2-yl)diphenylphosphine oxide. The compound crystallizes in the centrosymmetric space group <i>P</i>2₁/<i>n</i>, featuring two distinct conformational states (<b>S1</b> and <b>S2</b>) coexisting within the crystal structure. Experimental kinetic analysis in deuterated dimethyl sulfoxide revealed a rotational barrier of approximately 20 kcal mol⁻¹ (83.7 kJ mol⁻¹) (coalescence at 105°C), which effectively restricts interconversion at ambient temperatures. Notably, while ωB97XD/SMD calculations predict an intrinsic barrier of only 4.8 kcal mol⁻¹ (20.1 kJ mol⁻¹), experimental results demonstrate that explicit solute–solvent interactions significantly reinforce the rotational hindrance. This nearly fourfold increase highlights the decisive role of solvent-induced stabilization in governing conformational dynamics. Our findings indicate that the observed conformational integrity is not solely an intrinsic feature of the molecule but is critically dependent on the chemical environment, allowing for the observation of conformers despite their subtle thermodynamic differences.</p>","PeriodicalId":48737,"journal":{"name":"Journal of Applied Crystallography","volume":"59 5","pages":"1491-1499"},"PeriodicalIF":2.7,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149099607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of solidification history and particle size on defect evolution in Al2024 alloy additive manufacturing powder","authors":"Colby Azersky,&nbsp;Sangho Jeon,&nbsp;Matthias Kolbe,&nbsp;Caitlin Walde,&nbsp;Douglas Matson","doi":"10.1107/S1600576726006758","DOIUrl":"https://doi.org/10.1107/S1600576726006758","url":null,"abstract":"<p>This study investigates the impact of solidification history on defect evolution in Al2024 alloy additive manufacturing powder. A measurement utilizing synchrotron powder X-ray diffraction (XRD) was performed with a photon energy of 105.7 keV (0.1173 Å). XRD measurements were completed for six distinct particle diameter ranges from 20 to 63 µm of both as-atomized and annealed Al2024 samples. The dislocation density was determined using X-ray line profile analysis and ranged between 3.1 × 10¹⁴ and 7.4 × 10¹⁴ m⁻² for as-atomized samples, and between 1.3 × 10¹⁴ and 4.0 × 10¹⁴ m⁻² for annealed samples. The results of this investigation suggest a trend of decreasing dislocation density in as-atomized samples as the particle size increases, demonstrating the influence of particle size on defect formation. The annealed samples show a weak size dependence on the dislocation density across all particle sizes, affirming the efficacy of the annealing process in healing microstructural defects. The reduction in dislocation density upon annealing confirms that the dislocations in the as-atomized samples were introduced during rapid solidification and are largely removed by heat treatment. Field-emission scanning electron microscopy and electron backscatter diffraction (EBSD) were used in conjunction with image analysis tools to quantify the grain interface areas of the as-atomized samples and estimate cooling rates during solidification. Cooling rates were found to vary with particle size within a range of roughly 22000 to 164000 K s⁻¹. Results from both XRD analysis and metallography were used to predict average misorientation angles between grains; the predicted angles range from roughly 0.68° to 0.83°. EBSD was utilized to quantify average misorientation angles and compare them with the predicted values. The EBSD measured angles ranged from roughly 0.74° to 0.95° and followed the same trend as the predictions, linking the dislocation density to the cooling rate and solidification history of the powder. Quantifying the dislocation density and average misorientation angle provides a deeper understanding of the microstructure produced during rapid solidification. These results establish a physical relationship between particle size, cooling rate, dislocation density and grain misorientation during rapid solidification of Al2024 powder. This relationship is relevant to the study of solidification and to applications where gas-atomized powder is utilized without necessarily being fully remelted.</p>","PeriodicalId":48737,"journal":{"name":"Journal of Applied Crystallography","volume":"59 5","pages":"1384-1392"},"PeriodicalIF":2.7,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149099722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Absorption correction for plate samples in transmission X-ray powder diffraction: improved reliability of atomic displacement parameters","authors":"Hui Zhong,&nbsp;Jianming Bai","doi":"10.1107/S1600576726007454","DOIUrl":"https://doi.org/10.1107/S1600576726007454","url":null,"abstract":"<p>Absorption in transmission X-ray powder diffraction introduces angle-dependent intensity distortions that can bias refined structural parameters. We present an analytical absorption correction for flat plate samples, derived from the geometry and applicable to both point and area detectors. The correction separates into a scale term and an angle-dependent component; while the former is absorbed by the refinement scale factor, the latter affects relative intensities and biases parameters such as atomic displacement parameters (ADPs). Using CeO₂, we show that neglecting absorption leads to systematic variation of ADPs with optical thickness, which is removed by applying the correction. Plate geometry further allows independent determination of the optical thickness, enabling absorption to be treated as a physically constrained correction and improving refinement reliability.</p>","PeriodicalId":48737,"journal":{"name":"Journal of Applied Crystallography","volume":"59 5","pages":"1426-1431"},"PeriodicalIF":2.7,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149100541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"","authors":"","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":48737,"journal":{"name":"Journal of Applied Crystallography","volume":"59 5","pages":"1550-1556"},"PeriodicalIF":2.7,"publicationDate":"2026-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149100505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}