L-shell x-ray fluorescence relative intensities for elements with 62≤Z≤83 at 18 keV and 23 keV by synchrotron radiation

The relative intensities of L-subshell x-ray fluorescence(XRF)for elements with atomic numbers 62≤Z≤83 were measured at two excitation energies,18 keV and 23 keV,using a synchrotron radiation source at a beamline of the Synchrotron Light Center for Experimental Science and Applications in the Middle East(SESAME),Jordan.The experimentally measured results of the relative intensities were compared with the calculated results using the subshell fluorescence yield and the Coster-Kronig transition probabilities recommended by Campbell and the values based on the Dirac-Hartree-Slater model by Puri.The experimental and theoretical results are in agreement.In this work,L XRF relative intensities for the elements Sm,Gd,Tb,Er,Ta,W,Re,Hg,Pb and Bi at energies of 18 keV and 23 keV were measured.

Three dimensional distribution of surfactant in microspheres revealed by synchrotron radiation X-ray microcomputed tomography

This study investigated the formulation mechanism of microspheres via internal surfactant distribution. Eudragit L100 based microspheres loaded with bovine serum albumin were prepared by solid in oil in oil emulsion solvent evaporation method using acetone and liquid paraffin system containing sucrose stearate as a surfactant. The fabricated microspheres were evaluated for encapsulation efficiency, particle size, production yield, and in vitro release characteristics. The internal structures of microspheres were characterized using synchrotron radiation X-ray microcomputed tomography(SR-μCT). The enhanced contrast made the sucrose stearate distinguished from Eudragit to have its three dimensional(3D) distribution. Results indicated that the content and concentration determined the state of sucrose stearate and had significant influences on the release kinetics of protein. The dispersity of sucrose stearate was the primary factor that controlled the structure of the microspheres and further affected the encapsulation efficiency, effective drug loading, as well as in vitro release behavior. In conclusion, the 3D internal distribution of surfactant in microspheres and its effects on protein release behaviors have been revealed for the first time. The highly resolved 3D architecture provides new evidence for the deep understanding of the microsphere formation mechanism.

Small-angle X-ray scattering investigation of aging behavior of Al-Cu-Mg-Ag alloys using synchrotron radiation

The aging behavior of Al-Cu-Mg-Ag alloys with high Cu/Mg was studied by transmission electron microscopy (TEM) and small-angle X-ray scattering (SAXS) using synchrotron radiation. TEM study reveals that the major strengthening phases of the alloy after aging at 160?C for 10 h are Ω and less θ′. SAXS study shows that the scattering patterns are composed of several concentric circles at the beginning of aging process, which is replaced by the butterfly-wings scattering patterns with the increase of aging time. The butterfly-wings scattering patterns are composed of several branches. The angles between the branches are roughly equal to that between the habit planes of precipitates. The evolution of Guinier radius with aging time indicates the good coarsening resistance of the precipitates. The evolution of integrated intensity is consistent with the classical two-step precipitation process.

The Study Internal Structure of the Annual Layers in Lake Sediments Using Synchrotron Radiation with X-ray Focusing Optics

1 Introduction Annually laminated(varve)sedimentary deposits are considered as one of the most important archives,since they offer precise temporal information(years)in combination with high time resolutions.Bottom sediments of the lakes contain detailed geochemical information

The Significance of Solutions Obtained from Ill-Posed Systems of Linear Equations Constituted by Synchrotron Radiation Based Anomalous Small-Angle X-Ray Scattering

Synchrotron radiation based experimental techniques known as Anomalous Small-Angle X-ray Scattering (ASAXS) provide deep insight into the nanostructure of uncountable material systems in condensed matter research i.e. solid state physics, chemistry, engineering and life sciences thereby rendering the origin of the macroscopic functionalization of the various materials via correlation to its structural architecture on a nanometer length scale. The techniques constitute a system of linear equations, which can be treated by matrix theory. The study aims to analyze the significance of the solutions of the stated matrix equations by use of the so-called condition numbers first introduced by A. Turing, J. von Neumann and H. Goldstine. Special attention was given for the comparison with direct methods i.e. the Gaussian elimination method. The mathematical roots of ill-posed ASAXS equations preventing matrix inversion have been identified. In the framework of the theory of von Neumann and Goldstine the inversion of certain matrices constituted by ASAXS gradually becomes impossible caused by non-definiteness. In Turing’s theory which starts from more general prerequisites, the principal minors of the same matrices approach singularity thereby imposing large errors on inversion. In conclusion both theories recommend for extremely ill-posed ASAXS problems avoiding inversion and the use of direct methods for instance Gaussian elimination.

Characterization of metal element distributions in the rat brain following ischemic stroke by synchrotron radiation microfluorescence analysis

Ischemic stroke is one of the leading causes of death worldwide,and effective treatment strategies in the chronic phase of this disease remain insufficient.Homeostasis of metals in the brain plays an important role in maintaining normal brain function.However,the dynamic spatial distributions of iron,zinc,calcium,potassium,and copper in a rat brain following ischemic stroke and the association between structural distribution and function remain to be elucidated.In this study,we used a synchrotron radiation-based micro-X-ray fluorescence technique to image element mapping changes in special rat brain regions after ischemic stroke,showing the distribution characteristics of iron,zinc,calcium,potassium,and copper.We demonstrated,for the first time,the consistent dynamic spatial distributions of metal elements at a series of time points(3 h,4.5 h,6 h,12 h,1 d,3 d,5 d,7 d,10 d,14 d,28 d)after brain ischemia,which revealed that the homeostasis of iron,zinc,calcium,potassium,and copper in the brain was disturbed with distinctive change trends,providing clear insights in understanding the underlying pathogenesis of stroke from a novel perspective,thus laying the foundation of further developing new drug targets for stroke treatment.

Time-resolved ultra-small-angle X-ray scattering beamline(BL10U1)at SSRF

The construction of a new beamline,BL10U1,was completed at the Shanghai synchrotron radiation facility in 2020.This multipurpose beamline was designed to provide X-ray scattering techniques such as ultra-small-angle X-ray scattering(USAXS),small-angle X-ray scattering(SAXS),wide-angle X-ray scattering,and microfocus SAXS(μSAXS)for a broad user community.To realize fast time-resolved USAXS experiments,the beamline adopted an in-vacuum undulator with a total length of 1.6 m as the photon source.An in-house cryogenic-cooled double multilayer monochromator was installed to deliver a photon flux of approximately 10^(13) photons/s at a photon energy of 10 keV.The three-year successful operation of this beamline demonstrated that the monochromator operated smoothly,as expected.BL10U1 has three end stations in succession:USAXS end station,μSAXS end station,and end station for industrial applications.The minimum scattering vector q~0.0042 nm^(-1) at 10 keV can be achieved at the USAXS end station equipped with a 28 m-long and 1.8 m-diameter vacuum flight tube.At theμSAXS end station,a beam spot of less than 10×8μm was achieved for micro-SAXS experiments.In contrast,in situ experimental instruments up to 5 m high and 8 m wide can be mounted at the industrial application end station,which offers industrial scientists the opportunity to use their large industrial equipment.BL10U1 opens up a new capability to investigate phenomena such as non-equilibrium and dynamic processes of materials with a wide length scale from angstroms to micrometers with millisecond time resolution.In this paper,we also report beamline design considerations and commissioning results.

Scanning Analysis of REE in Bastnaesite with Synchrotron Radiation X－Ray Fluorescence Microprobe

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Scan system for arbitrary-shaped samples at the synchrotron radiation facility

X-ray fluorescence(XRF) scan methodology is important for elemental mapping of samples at a synchrotron radiation facility. To save the experiment time and improve the experiment efficiency, one should develop an efficient XRF scan method. In this paper, a new scan mode is presented. It can map arbitrary-shaped areas withou stopping the motors. The control and data acquisition system integrates motor controlling, detector triggering, and data acquisition and storage. The system realizes the arbitrary-shaped 2D-mapping and fluorescence data acquisition synchronously. SR-XRF mapping has been performed with a standard gold mask to verify the validity of this method a beamline BL15U1 of the Shanghai Synchrotron Radiation Facility. The results show that this method reduces the tota scan time and improves the experiment efficiency.

Three-dimensional morphology of the Sinocyclocheilus hyalinus(Cypriniformes:Cyprinidae)horn based on synchrotron X-ray microtomography

Sinocyclocheilus is a cave-dwelling cyprinid genus endemic to southwest China.Several species possess a conspicuous horn on their head,which has been suggested as a constructive troglomorphic trait but lacks substantial evidence.We used non-invasive,high spatial resolution synchrotron X-ray microtomography to investigate the three-dimensional(3D)morphology of the horn of Sinocyclocheilus hyalinus,one of eight such troglobiotic species.3D renderings demonstrated the osteological components,which were comprised of a rear wall comprised of the supraoccipital bone,a remaining frontal wall with numerous fenestrae,and the bottom continuous with the parietal and epiotic.A horn cavity occurred within the horn.The fenestrae in the frontal wall were continuous in the horn cavity and showed elaborate channeling,and were,connected to the cranial cavity by soft tissue.We tentatively called this configuration the“otocornual connection”due to its anatomic and putative functional similarity to the otolateralic connection in clupeids and loricariids,which provide an indirect pathway to enhance perception of underwater sound signals.This study provides a functional morphology context for further histological and physiological investigations of such horn structures in Sinocyclocheilus cavefish,and we suggest that the horn might enhance acoustic perception to compensate for visual loss in subterranean life,which warrants future physiological examination as lab-reared S.hyalinus become available.

Characterization of Porosity in a Laser Sintered MMCp Using X-Ray Synchrotron Phase Contrast Microtomography

Direct Laser Sintering (DSL), a technology enabling the production of dense metal components directly from 3D CAD data, was used for the first time to produce a Metal Matrix Composite (MMCp) based on Al-Si-Cu alloy in view of its application in different fields, in particular for aeronautics. The porosity of the material obtained so was investigated by using optical and electron microscopy and, in particular, X-ray computed microtomography techniques. DSL is a unique technique to produce complex components in an economical way while computed microtomography is a unique technique to evaluate the porosity and pore and cracks distribution in a not destructive way. A near homogeneous distribution of the porosity and pore sizes was observed both comparing different regions of the same specimen and also by comparing different samples obtained by using the same DLS production method. A quantitative analysis of the damage in the composite is also reported.

Performance of the merged APPLE-Knot undulator for soft x-ray beamline in medium energy ring

APPLE-Knot undulator can effectively solve the on-axis heat load problem and is proven to perform well in VUV beamline and soft x-ray beamline in high energy storage ring. However, for soft x-ray beamline in a medium energy ring,whether the APPLE-Knot undulator excels the APPLE undulator is still a question. Here, a merged APPLE-Knot undulator is studied to generate soft x-ray in a medium energy ring. Its advantages and problems are discussed. Though the on-axis heat load of the APPLE-Knot undulator is lower in linear polarization modes compared to the APPLE undulator, its flux is lower. The APPLE-Knot undulator shows no advantage when only fundamental harmonic is needed. However, in circular polarization mode, the APPLE-Knot undulator shows the ability to cover a broader energy range which can remedy the notable shortcoming of the APPLE undulator.

The new X-ray imaging and biomedical application beamline BL13HB at SSRF

A new X-ray imaging and biomedical application beamline(BL13HB)has been implemented at the Shanghai Radiation Synchrotron Facility(SSRF)as an upgrade to the old X-ray imaging and biomedical application beamline(BL13W1).This is part of the Phase II construction project of the SSRF.The BL13HB is dedicated to 2D and 3D static and dynamic X-ray imaging,with a field of view of up to 48.5 mm×5.2 mm and spatial resolution as high as 0.8μm.A super-bending magnet is used as the X-ray source in BL13HB,which has a maximum magnetic field of 2.293 T.The energy range of monochromatic X-ray photons from a double-multiplayer monochromator was 8–40 keV,and the white beam mode was provided on the beamline for dynamic X-ray imaging and dynamic X-ray micro-CT.While maintaining the previous experimental setup of BL13W1,new equipment was added to the beamline experimental station.The beamline is equipped with different sets of X-ray imaging detectors for several experimental methods such as micro-CT,dynamic micro-CT,and pair distribution function.The experimental station of BL13HB is designed specifically for various in situ dynamic experiments,and BL13HB has been open to users since June 2021.

Machine learning super-resolution of laboratory CT images in all-solid-state batteries using synchrotron radiation CT as training data

High-performance all-solid-state lithium-ion batteries require observation,control,and optimization of the electrode structure.X-ray computational tomography(CT)is an effective nondestructive method for observing the electrode structure in three dimensions.However,the limited availability of synchrotron radiation CT,which offers high-resolution imaging with a high signal-to-noise ratio,makes it difficult to conduct experiments and restricts the use of X-ray CT in battery development.Conversely,laboratory CT systems are widely available,but they use X-rays emitted from a metal target,resulting in lower image quality and resolution compared with synchrotron radiation CT.This study explores a method for achieving comparable resolution in laboratory CT images of all-solid-state batteries to that of synchrotron radiation CT.Our method involves using the synchrotron radiation CT images as training data for machine learning super-resolution.The results demonstrate that,by employing an appropriate machine learning algorithm and activation function,along with a sufficiently deep network,the image quality of laboratory CT becomes equivalent to that of synchrotron radiation CT.

Synchrotron radiation X-ray diffraction in situ study of fine-grained minerals in shock veins of Suizhou meteorite

The synchrotron radiation X-ray diffraction technique developed for in situ study ahigh pressure and temperature has also been used to investigate microscopic mineral inclusionsin ultrahigh-pressure metamorphic rocks and deep-mantle samples. Present study added twomore examples of successful utilization of synchrotron radiation X-ray diffraction technique for insitu investigations of fine-grained (0.5―30 μm in size) minerals in very thin shock melt veins othe Suizhou meteorite: ( i ) X-ray diffraction measurement of extremely small-sized vein matrixminerals, and (ii) identification of the micron-sized new mineral tuite embedded in the vein matrixIt has been revealed that the fine-grained vein matrix consists of well crystallized garnet, kamacite and troilite, and the powder diffraction pattern consisting of 17 lines with d-values, intensities( I ), relative intensities (I/Io) and Miller indices, as well as the cell parameters for the new mineratuite has also been successfully obtained. The result of present investigations has enriched thecontent of dynamic high-pressure mineralogy and that of Earth’s mantle geochemistry.

Establishment of Energy Dispersive X-ray Diffraction Experimental System With Synchrotron Radiation Under High Pressure

Because the interactions between molecules and atoms in mediums can be dramatically changed by compression, high pressure studies on materials can provide much information on fundamental properties including phase transition and

BL19U2:Small-angle X-ray scattering beamline for biological macromolecules in solution at SSRF

The BL19U2 at the Shanghai Synchrotron Radiation Facility is a small-angle X-ray scattering beamline dedicated to structural studies pertaining to biological macromolecules in solution.The beamline has been officially opened to users in March 2015,and since then,a series of technological innovations has been developed to optimize beamline performance,thereby significantly improving the data collection efficiency and broadening the application scope of biological small-angle X-ray scattering.BL19U2 is ideal for the high-throughput screening of weakly scattered proteins,protein assemblies,nucleic acids,inorganic nanomaterials,and organic drug molecules.This paper describes the design and overview of the BL19U2 beamline.Versatile sample environments at the experimental station and some recent scientific highlights are presented.

Synchrotron-Based Data-Constrained Modeling Analysis of Microscopic Mineral Distributions in Limestone

Three dimensional (3D) microscopic distributions of dolomite and calcite in a limestone sample have been analyzed with a data-constrained modeling (DCM) technique using synchrotron radiation-based multi-energy X-ray computed tomography (CT) data as constraints. In order to optimize the experimental parameters, X-ray CT simulations and DCM analysis of a numerical phantom consisting of calcite (CaCO3) and dolomite (CaMg(CO3)2) have been used to investigate the effects on the predicted results in relation to noise, X-ray energy and sample-to-detector distance (SDD). The simulation results indicate that the optimal X-ray energies are 25 and 35 keVs, and the SDD is 10 mm. The high resolution 3D distributions of mineral phases of a natural limestone have been obtained. The results are useful for quantitative understanding of mineral, porosity, and physical property distributions in relation to oil and gas reservoirs hosted in carbonate rocks, which account for more than half of the world’s conventional hydrocarbon resources. The case studied is also instructive for the applicability of the DCM methods for other types of composite materials with modest atomic number contrasts between the mineral phases.

Analysis of nickel distribution by synchrotron radiation X-ray fluorescence in nickel-induced early- and late-phase allergic contact dermatitis in Hartley guinea pigs

Background: Nickel-induced allergic contact dermatitis (Ni-ACD) is a global health problem. More detailed knowledge on the skin uptake of haptens is required. This study aimed to investigate the penetration process and distribution of nickel in skin tissues with late phase and early phase of Ni-ACD to understand the mechanisms of metal allergy. Methods: Forty Hartley guinea pigs were divided into four groups according to the NiSO4 sensitizing concentration and the NiSO4 challenged concentration: the 5% NiSO4-group, 5% to 10%(sensitization-challenge;late phase group);10% NiSO4-group, 10% to 10%(sensitization-challenge;early-phase group);and the positive and negative controls. Pathological biopsies were performed on each group. The depth profile of nickel element concentration in the skin of guinea pigs was detected by synchrotron radiation micro X-ray fluorescence spectroscopy (SR-μ-XRF) and micro X-ray absorption near-edge spectroscopy (μ-XANES). Results: In each section, the nickel element concentration in both the 5% NiSO4-group and 10% NiSO4-group was significantly higher than that in the negative control group. In the upper 300-μm section of skin for the early phase group, the nickel element concentration was significantly higher than that in the lower section of skin. In deeper sections (>200 μm) of skin, the concentration of nickel in the early phase group was approximately equal to that in the late phase group. The curve of the late phase group was flat, which means that the nickel element concentration was distributed uniformly by SR-μ-XRF. According to the XANES data for the 10% NiSO4 metal salt solution, structural changes occurred in the skin model sample, indicating that nickel was not present in the Ni^2+ aqueous ionic state but in the nickel-binding protein. Conclusions: This study showed that the distribution of the nickel element concentration in ACD skin tissue was different between the early phase and late phase groups. The nickel element was not present in the Ni^2+ aqueous ionic state but bound with certain proteins to form a complex in the stratum corneum in ACD model tissue.

Hard X-ray focusing resolution and efficiency test with a thickness correction multilayer Laue lens

The multilayer Laue lens(MLL) is a diffractive focusing optical element which can focus hard X-rays down to the nanometer scale. In this study, a WSi_(2)/Si multilayer structure consisting of 1736 layers, with a 7.2-nm-thick outermost layer and a total thickness of 17 μm, is prepared by DC magnetron sputtering. Regarding the thin film growth rate calibration, we correct the long-term growth rate drift from 2 to 0.6%, as measured by the grazing incidence X-ray reflectivity(GIXRR). A one-dimensional line focusing resolution of 64 nm was achieved,while the diffraction efficiency was 38% of the-1 order of the MLL Shanghai Synchrotron Radiation Facility(SSRF) with the BL15U beamline.