Thematische Bibliographien / Synchrotron-based XRT

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Auswahl der wissenschaftlichen Literatur zum Thema „Synchrotron-based XRT“

Autor: Grafiati

Veröffentlicht am 24. Juni 2021

Zuletzt aktualisiert am 6. Februar 2022

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Zeitschriftenartikel zum Thema "Synchrotron-based XRT"

Yao, Yong Zhao, Yukari Ishikawa, Yoshihiro Sugawara, Koji Sato, Katsunori Danno, Takayuki Shirai, Kazuaki Sato et al. „Dislocations in SiC Revealed by NaOH Vapor Etching and a Comparison with X-Ray Topography Taken with Various g-Vectors“. Materials Science Forum 858 (Mai 2016): 389–92. http://dx.doi.org/10.4028/www.scientific.net/msf.858.389.

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Threading dislocations (TDs) in 4H-SiC have been studied by comparing etch pits formed by NaOH vapor etching with results of synchrotron monochromatic-beam X-ray topography (XRT) taken under different g-vectors. Burgers vectors determined based on XRT results were utilized to investigate the etch pit characteristics of edge (TED), screw (TSD) and mixed (Burgers vector b=c+a, TMD) threading dislocations. It has been found that pit formation by NaOH vapor etching was very different to that by conventional molten KOH etching. We discuss the possibility of using NaOH vapor etching to distinguish TMDs from TSDs, and report a variety of characteristic etch pits formed by this method and their correlations to dislocation behavior.

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Dalmau, Rafael, Jeffrey Britt, Hao Yang Fang, Balaji Raghothamachar, Michael Dudley und Raoul Schlesser. „X-Ray Topography Characterization of Large Diameter AlN Single Crystal Substrates“. Materials Science Forum 1004 (Juli 2020): 63–68. http://dx.doi.org/10.4028/www.scientific.net/msf.1004.63.

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Large diameter aluminum nitride (AlN) substrates, up to 50 mm, were manufactured from single crystal boules grown by physical vapor transport (PVT). Synchrotron-based x-ray topography (XRT) was used to characterize the density, distribution, and type of dislocations. White beam topography images acquired in transmission geometry were used to analyze basal plane dislocations (BPDs) and low angle grain boundaries (LAGBs), while monochromatic beam, grazing incidence images were used to analyze threading dislocations. Boule diameter expansion, without the introduction of LAGBs around the periphery, was shown. A 48 mm substrate with a uniform threading dislocation density below 7.0 x 102 cm-2 and a BPD of 0 cm-2, the lowest dislocation densities reported to date for an AlN single crystal this size, was demonstrated.

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Acciari, MAGIC Collaboration: V. A., S. Ansoldi, L. A. Antonelli, A. Arbet Engels, A. Babić, B. Banerjee, U. Barres de Almeida et al. „An intermittent extreme BL Lac: MWL study of 1ES 2344+514 in an enhanced state“. Monthly Notices of the Royal Astronomical Society 496, Nr. 3 (17.06.2020): 3912–28. http://dx.doi.org/10.1093/mnras/staa1702.

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ABSTRACT Extreme high-frequency BL Lacs (EHBL) feature their synchrotron peak of the broad-band spectral energy distribution (SED) at νs ≥ 1017 Hz. The BL Lac object 1ES 2344+514 was included in the EHBL family because of its impressive shift of the synchrotron peak in 1996. During the following years, the source appeared to be in a low state without showing any extreme behaviours. In 2016 August, 1ES 2344+514 was detected with the ground-based γ-ray telescope FACT during a high γ-ray state, triggering multiwavelength (MWL) observations. We studied the MWL light curves of 1ES 2344+514 during the 2016 flaring state, using data from radio to very-high-energy (VHE) γ-rays taken with OVRO, KAIT, KVA, NOT, some telescopes of the GASP-WEBT collaboration at the Teide, Crimean, and St. Petersburg observatories, Swift-UVOT, Swift-XRT, Fermi-LAT, FACT, and MAGIC. With simultaneous observations of the flare, we built the broad-band SED and studied it in the framework of a leptonic and a hadronic model. The VHE γ-ray observations show a flux level of 55 per cent of the Crab Nebula flux above 300 GeV, similar to the historical maximum of 1995. The combination of MAGIC and Fermi-LAT spectra provides an unprecedented characterization of the inverse-Compton peak for this object during a flaring episode. The Γ index of the intrinsic spectrum in the VHE γ-ray band is 2.04 ± 0.12stat ± 0.15sys. We find the source in an extreme state with a shift of the position of the synchrotron peak to frequencies above or equal to 1018 Hz.

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Smieska, Louisa M., Arthur R. Woll, Frederik Vanmeert und Koen Janssens. „Synchrotron-Based High-Energy X-ray MA-XRF and MA-XRD for Art and Archaeology“. Synchrotron Radiation News 32, Nr. 6 (02.11.2019): 29–33. http://dx.doi.org/10.1080/08940886.2019.1680212.

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Gorenstein, Paul. „Focusing X-Ray Optics for Astronomy“. X-Ray Optics and Instrumentation 2010 (27.12.2010): 1–19. http://dx.doi.org/10.1155/2010/109740.

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Focusing X-ray telescopes have been the most important factor in X-ray astronomy’s ascent to equality with optical and radio astronomy. They are the prime tool for studying thermal emission from very high temperature regions, non-thermal synchrotron radiation from very high energy particles in magnetic fields and inverse Compton scattering of lower energy photons into the X-ray band. Four missions with focusing grazing incidence X-ray telescopes based upon the Wolter 1 geometry are currently operating in space within the 0.2 to 10 keV band. Two observatory class missions have been operating since 1999 with both imaging capability and high resolution dispersive spectrometers. They are NASA’s Chandra X-ray Observatory, which has an angular resolution of 0.5 arc seconds and an area of 0.1 m2 and ESA’s XMM-Newton which has 3 co-aligned telescopes with a combined effective area of 0.43 m2 and a resolution of 15 arc seconds. The two others are Japan’s Suzaku with lower spatial resolution and non-dispersive spectroscopy and the XRT of Swift which observes and precisely positions the X-ray afterglows of gamma-ray bursts. New missions include focusing telescopes with much broader bandwidth and telescopes that will perform a new sky survey. NASA, ESA, and Japan’s space agency are collaborating in developing an observatory with very large effective area for very high energy resolution dispersive and non-dispersive spectroscopy. New technologies are required to improve upon the angular resolution of Chandra. Adaptive optics should provide modest improvement. However, orders of magnitude improvement can be achieved only by employing physical optics. Transmitting diffractive-refractive lenses are capable theoretically of achieving sub-milli arc second resolution. X-ray interferometry could in theory achieve 0.1 micro arc second resolution, which is sufficient to image the event horizon of super massive black holes at the center of nearby active galaxies. However, the physical optics systems have focal lengths in the range 103 to 104 km and cannot be realized until the technology for accurately positioned long distance formation flying between optics and detector is developed.

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Kim, Julie J., Florence T. Ling, Dan A. Plattenberger, Andres F. Clarens, Antonio Lanzirotti, Matthew Newville und Catherine A. Peters. „SMART mineral mapping: Synchrotron-based machine learning approach for 2D characterization with coupled micro XRF-XRD“. Computers & Geosciences 156 (November 2021): 104898. http://dx.doi.org/10.1016/j.cageo.2021.104898.

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Xia, Jin Lan, Hong Chang Liu, Zhen Yuan Nie, Hong Rui Zhu, Yun Yang, Lei Wang, Jian Jun Song et al. „Characterization of Microbe-Mineral Interfacial Interaction Based on Synchrotron Radiation Techniques“. Advanced Materials Research 1130 (November 2015): 123–26. http://dx.doi.org/10.4028/www.scientific.net/amr.1130.123.

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This article presents the progress on characterization of the interfacial interaction between sulfur oxidizing microbes and sulfide minerals by using of synchrotron radiation-based techniques including S/Fe/Cu X-ray absorption near-edge structure spectroscopy (XANES), X-ray Diffraction (XRD), micro-X-ray fluorescence (μ-XRF) mapping and micro-scanning transmission X-ray microscopy (μ-STXM) imaging, together with other accessory approaches such as SEM/EDS, Raman spectroscopy, FT-IR spectroscopy, and electrochemical methods as well as comparative proteomics methodology.

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Gonzalez, Victor, Annelies van Loon, Stephen WT Price, Petria Noble und Katrien Keune. „Synchrotron micro-XRD and micro-XRD-CT reveal newly formed lead–sulfur compounds in Old Master paintings“. Journal of Analytical Atomic Spectrometry 35, Nr. 10 (2020): 2267–73. http://dx.doi.org/10.1039/d0ja00169d.

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Garg, Alka B., P. Thangadurai, S. Meenakshi und S. Ramasamy. „Synchrotron based XRD study on nano crystalline SnO2under pressure“. Journal of Physics: Conference Series 377 (30.07.2012): 012022. http://dx.doi.org/10.1088/1742-6596/377/1/012022.

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Rao, D. V., G. E. Gigante, R. Cesareo, A. Brunetti, N. Schiavon, T. Akatsuka, T. Yuasa und T. Takeda. „Synchrotron-based XRD from rat bone of different age groups“. Materials Science and Engineering: C 74 (Mai 2017): 207–18. http://dx.doi.org/10.1016/j.msec.2016.11.136.

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Dissertationen zum Thema "Synchrotron-based XRT"

Askengren, Albert. „Evaluation of tomographic methods for limestone characterization : Using synchrotron-based X-ray tomography todetermine porosity, internal structure andinternal distributions in limestone“. Thesis, Umeå universitet, Institutionen för fysik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-184937.

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Limestone is a raw material in the cement and quicklime industry and knowledge about limestone characteristics can help improve and optimize production processes. In the end this can lead to a reduction in CO2 emissions from the industry. In this project X-ray tomography (XRT) was used to examine limestone samples. The aim was to determine if XRT, including synchrotron-based XRT, is a reliablemethod to determine porosity, pore structure and internal distributions of pores and pyrite (FeS2) grains in limestone. The aim also included to determine if XRT could be used to resolve material variations, fine-grained and larger crystals in limestone. In total, there were ten limestone samples and the performed XRT was done by Advanced Light Source (ALS) in Berkeley, California and by Luleå University of Technology. A brief comparison between ALS and Luleå was also done by inspectingsamples that have been through XRT at both facilities. The main software used foranalysis was Avizo v.9.2.0. The results showed that XRT is a suitable method for determining porosity and pore distribution. Interactive thresholding was used in Avizo for measuring porosity. The porosity was determined as a single value and as a narrow range, where a narrow range was more reliable. XRT was also found to be a suitable method for visually determining a variety of textures within the samples. Areas with different materials(such as dolomite) and/or newly-formed crystals were visually distinguishable but individual newly-formed crystals were not as clear when compared to scanning electron microscopy. Individual older fine-grained and larger crystals were hard to resolve. Internal distributions in 3D of both pores and pyrite grains were possible to obtain with XRT. The analysis of internal distributions was found to be a clear advantage with the method of XRT. The equivalent diameter of pores and pyrite grains was also measured and plotted in histograms. The XRT performed at ALS had higher resolution than the XRT performed in Luleå (0.65 vs 2 μm). Lower resolution over-estimated the average equivalent diameter of pores, and boundaries of pores and cavities were harder to see. Therefore, the higher resolution from ALS was preferable. These results contribute to understanding limestone characteristics.

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Li, Chun. „Measurement and understanding the residual stress distribution as a function of depth in atmosphere plasma sprayed thermal barrier coatings“. Thesis, University of Manchester, 2018. https://www.research.manchester.ac.uk/portal/en/theses/measurement-and-understanding-the-residual-stress-distribution-as-a-function-of-depth-in-atmosphere-plasma-sprayed-thermal-barrier-coatings(e4dd38cc-2800-4719-bfe5-cccd0d6ff8c8).html.

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Residual stresses are generally considered to be the driving forces for the failure of APS TBCs. In this thesis, the residual stress distribution as a function of depth in APS TBC has been measured by synchrotron XRD and explained by image based modelling based on the microstructure detailed studied by SEM and CT. The residual stress/ strain distribution as a function of depth was measured by synchrotron XRD in transmission and reflection geometry. The residual stress/ strain values were analysed using full pattern Rietveld refinement, the sin square psi method and XRD2 method. For the reflection geometry, a new method was developed to deconvolute the residual stress value in each depth from the measured averaged values. Two types of residual stress/strain distribution were observed. The first kind of residual stress was found to be compressive and followed a non-linear trend, which increased from the surface to the interface, decreased slightly and increased again to the interface. This trend showed a jump feature near the interface. The second kind of residual stress distribution possessed two jump features: one near the interface similar to the first kind and another jump feature near the sample surface. The residual stress in both beta and gama phase in the bond coat were also investigated which showed a tensile stress state. The stress trend predicted by our analytical model followed a linear relationship. Comparing this with the first kind of residual stress distribution, two main differences were shown. Firstly the jump feature near the interface and secondly the much larger overall stress gradient. The 3D and 2D microstructure of the sample with the first kind of residual stress distribution was observed by X-ray CT and SEM. The effect of pores, inter-splat cracks and the rumpling interface on the residual stress distribution was investigated by image based modelling. It was proved that the pores and the inter-splat cracks had no large influence on the stress distribution and the jump feature near the interface was a result of the rumpling interface. The much larger stress gradient observed in the measured residual stress distribution was an indication of the stress relaxation in the coating which was proved by a specially designed mechanical test. To explain the jump feature near the sample surface in the second kind of stress distribution. 3D microstructures of the measured samples were observed using X-ray CT. The effect of vertical and the side cracks on the stress distribution were investigated by image based modelling. It was found that the vertical crack had no large influence on the residual stress distribution and the jump feature in the stress trend near the surface could be attributed to the side crack. The effect of other kinds of cracks that were not directly observed in our samples, such as middle or through side cracks, were also investigated. These results were used to develop a semi-destructive method to determine the existence and distribution of cracks in APS TBC.

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Rahn, Helene. „Semi-quantitative röntgentomographische Untersuchungen zur Biodistribution von magnetischen Nanopartikeln in biologischem Gewebe“. Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-83592.

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Im Rahmen der vorliegenden Dissertationsschrift „Semi-quantitative röntgentomographische Untersuchungen zur Biodistribution von magnetischen Nanopartikeln in biologischem Gewebe“ wurden tomographische Untersuchungen an biologischen Objekten durchgeführt. Bei diesen Objekten handelt es sich um Gewebeproben nach minimal-invasiven Krebstherapien wie zum Beispiel magnetischem Drug Targeting und magnetischer Wärmebehandlung. Der Erfolg dieser Therapien ist sowohl abhängig von der korrekten Verteilung der magnetischen Nanopartikel als auch von der Tatsache, dass diese in der Zielregion in einer ausreichenden Menge vorhanden sind. Das Vorliegen dieser beiden Voraussetzungen ist in der vorliegenden Arbeit untersucht worden. Dabei lag der Schwerpunkt der Arbeit auf der Quantifizierung von magnetischem Material in unterschiedlichen biologischen Gewebeproben mittels Röntgenmikrocomputertomographie (XµCT). Für diesen Zweck wurde ein Kalibrationssystem mit speziellen Phantomen entwickelt, mit dessen Hilfe eine Nanopartikelkonzentration einem Grauwert voxelweise zugewiesen werden kann. Mit Hilfe der Kalibration kann der Nanopartikelgehalt sowohl in monochromatischen als auch in polychromatischen tomographischen Daten im Vergleich zu magnetorelaxometrischen Ergebnissen mit wenigen Prozent Abweichung ermittelt werden. Trotz Polychromasie und damit einhergehenden Artefakten können 3-dimensionale röntgentomographische Datensätze mit einer geringfügigen Konzentrationsabweichung im Vergleich zur quantitativen Messmethode Magnetorelaxometrie semi-quantitativ ausgewertet werden
The success of the minimal invasive cancer therapies, called magnetic drug targeting and magnetic heating treatment, depends strongly on the correct distribution of the magnetic nanoparticles on one side. On the other side it depends on the fact that a sufficient amount of magnetic nanoparticles carrying drugs is accumulated in the target region. To study whether these two requirements are fulfilled motivates this PhD thesis „Semi-quantitative X-ray-tomography examinations of biodistribution of magnetic nanoparticles in biological tissues“. The analysis of the distribution of the magnetic nanoparticles in tumours and other tissue examples is realized by means of X-ray-micro computer tomography (XμCT). The work focuses on the quantification of the magnetic nanoparticles in different biological tissue samples by means of XµCT. A calibration of the tomographic devices with adequate phantoms, developed in the frame of this work, opens now the possibility to analyze tomographic data in a semi-quantitative manner. Thus, the nanoparticle concentration can be allocated voxel-wise to the grey values of the three-dimensional tomographic data. With the help of calibration of the tomography equipments used, polychromatic as well as monochromatic three-dimensional representations of objects can be analyzed with regard to the biodistribution of magnetic nanoparticles as well as with regard to their quantity. The semi-quantitative results have been compared with results obtained with a quantitative measurement method magnetorelaxometry (MRX). Thereby a good agreement of the semi-quantitative and quantitative data has been figured out

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Pohlmann, Tobias. „Structural and magnetic properties of ultrathin Fe3O4 films: cation- and lattice-site-selective studies by synchrotron radiation-based techniques“. Doctoral thesis, 2021. https://repositorium.ub.uni-osnabrueck.de/handle/urn:nbn:de:gbv:700-202108195272.

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This work investigates the growth dynamic of the reactive molecular beam epitaxy of Fe3O4 films, and its impact on the cation distribution as well as on the magnetic and structural properties at the surface and the interfaces. In order to study the structure and composition of Fe3O4 films during growth, time-resolved high-energy x-ray diffraction (tr-HEXRD) and time-resolved hard x-ray photoelectron spectroscopy (tr-HAXPES) measurements are used to monitor the deposition process of Fe3O4 ultrathin films on SrTiO3(001), MgO(001) and NiO/MgO(001). For Fe3O4\SrTiO3(001) is found that the film first grows in a disordered island structure, between thicknesses of 1.5nm to 3nm in FeO islands and finally in the inverse spinel structure of Fe3O4, displaying (111) nanofacets on the surface. The films on MgO(001) and NiO/MgO(001) show a similar result, with the exception that the films are not disordered in the early growth stage, but form islands which immediately exhibit a crystalline FeO phase up to a thickness of 1nm. After that, the films grown in the inverse spinel structure on both MgO(001) and NiO/MgO(001). Additionally, the tr-HAXPES measurements of Fe3O4/SrTiO3(001) demonstrate that the FeO phase is only stable during the deposition process, but turns into a Fe3O4 phase when the deposition is interrupted. This suggests that this FeO layer is a strictly dynamic property of the growth process, and might not be retained in the as-grown films. In order to characterize the as-grown films, a technique is introduced to extract the cation depth distribution of Fe3O4 films from magnetooptical depth profiles obtained by fitting x-ray resonant magnetic reflectivity (XRMR) curves. To this end, x-ray absorption (XAS) and x-ray magnetic circular dichroism (XMCD) spectra are recorded as well as XRMR curves to obtain magnetooptical depth profiles. To attribute these magnetooptical depth profiles to the depth distribution of the cations, multiplet calculations are fitted to the XMCD data. From these calculations, the cation contributions at the three resonant energies of the XMCD spectrum can be evaluated. Recording XRMR curves at those energies allows to resolve the magnetooptical depth profiles of the three iron cation species in Fe3O4. This technique is used to resolve the cation stoichiometry at the surface of Fe3O4/MgO(001) films and at the interfaces of Fe3O4/MgO(001) and Fe3O4/NiO. The first unit cell of the Fe3O4(001) surface shows an excess of Fe3+ cations, likely related to a subsurface cation-vacancy reconstruction of the Fe3O4(001) surface, but the magnetic order of the different cation species appears to be not disturbed in this reconstructed layer. Beyond this layer, the magnetic order of all three iron cation species in Fe3O4/MgO(001) is stable for the entire film with no interlayer or magnetic dead layer at the interface. For Fe3O4/NiO films, we unexpectedly observe a magnetooptical absorption at the Ni L3 edge in the NiO film corresponding to a ferromagnetic order throughout the entire NiO film, which is antiferromagnetic in the bulk. Additionally, the magnetooptical profiles indicate a single intermixed layer containing both Fe2+ and Ni2+ cations.

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Rahn, Helene. „Semi-quantitative röntgentomographische Untersuchungen zur Biodistribution von magnetischen Nanopartikeln in biologischem Gewebe“. Doctoral thesis, 2011. https://tud.qucosa.de/id/qucosa%3A25902.

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Im Rahmen der vorliegenden Dissertationsschrift „Semi-quantitative röntgentomographische Untersuchungen zur Biodistribution von magnetischen Nanopartikeln in biologischem Gewebe“ wurden tomographische Untersuchungen an biologischen Objekten durchgeführt. Bei diesen Objekten handelt es sich um Gewebeproben nach minimal-invasiven Krebstherapien wie zum Beispiel magnetischem Drug Targeting und magnetischer Wärmebehandlung. Der Erfolg dieser Therapien ist sowohl abhängig von der korrekten Verteilung der magnetischen Nanopartikel als auch von der Tatsache, dass diese in der Zielregion in einer ausreichenden Menge vorhanden sind. Das Vorliegen dieser beiden Voraussetzungen ist in der vorliegenden Arbeit untersucht worden. Dabei lag der Schwerpunkt der Arbeit auf der Quantifizierung von magnetischem Material in unterschiedlichen biologischen Gewebeproben mittels Röntgenmikrocomputertomographie (XµCT). Für diesen Zweck wurde ein Kalibrationssystem mit speziellen Phantomen entwickelt, mit dessen Hilfe eine Nanopartikelkonzentration einem Grauwert voxelweise zugewiesen werden kann. Mit Hilfe der Kalibration kann der Nanopartikelgehalt sowohl in monochromatischen als auch in polychromatischen tomographischen Daten im Vergleich zu magnetorelaxometrischen Ergebnissen mit wenigen Prozent Abweichung ermittelt werden. Trotz Polychromasie und damit einhergehenden Artefakten können 3-dimensionale röntgentomographische Datensätze mit einer geringfügigen Konzentrationsabweichung im Vergleich zur quantitativen Messmethode Magnetorelaxometrie semi-quantitativ ausgewertet werden.
The success of the minimal invasive cancer therapies, called magnetic drug targeting and magnetic heating treatment, depends strongly on the correct distribution of the magnetic nanoparticles on one side. On the other side it depends on the fact that a sufficient amount of magnetic nanoparticles carrying drugs is accumulated in the target region. To study whether these two requirements are fulfilled motivates this PhD thesis „Semi-quantitative X-ray-tomography examinations of biodistribution of magnetic nanoparticles in biological tissues“. The analysis of the distribution of the magnetic nanoparticles in tumours and other tissue examples is realized by means of X-ray-micro computer tomography (XμCT). The work focuses on the quantification of the magnetic nanoparticles in different biological tissue samples by means of XµCT. A calibration of the tomographic devices with adequate phantoms, developed in the frame of this work, opens now the possibility to analyze tomographic data in a semi-quantitative manner. Thus, the nanoparticle concentration can be allocated voxel-wise to the grey values of the three-dimensional tomographic data. With the help of calibration of the tomography equipments used, polychromatic as well as monochromatic three-dimensional representations of objects can be analyzed with regard to the biodistribution of magnetic nanoparticles as well as with regard to their quantity. The semi-quantitative results have been compared with results obtained with a quantitative measurement method magnetorelaxometry (MRX). Thereby a good agreement of the semi-quantitative and quantitative data has been figured out.

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Buchteile zum Thema "Synchrotron-based XRT"

Liao, Rui, Jun Wang, Shitong Liu, Hao Lin, Mo Lin und Shichao Yu. „XRD and Synchrotron-Based XRD Study of Chalcopyrite Leaching Catalyzed by Silver Ions“. In TMS 2020 149th Annual Meeting & Exhibition Supplemental Proceedings, 1823–31. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-36296-6_168.

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Wang, Xingxing, Maoxing Hong, Rui Liao, Chunxiao Zhao, Shichao Yu, Jun Wang, Hongbo Zhao und Min Gan. „Synchrotron-Based XRD and XANES Study of Bornite Leached by Mesophilic Mixed Bacteria“. In The Minerals, Metals & Materials Series, 325–32. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-72484-3_35.

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Konferenzberichte zum Thema "Synchrotron-based XRT"

Mo, Kun, Hsiao-Ming Tung, Xiang Chen, Weiying Chen, Jon B. Hansen, James F. Stubbins, Meimei Li und Jonathon Almer. „Synchrotron Radiation Study on Alloy 617 and Alloy 230 for VHTR Application“. In ASME 2011 Pressure Vessels and Piping Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/pvp2011-57393.

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High-energy synchrotron radiation has proven to be a powerful technique for investigating fundamental deformation processes for various materials, particularly metals and alloys. In this study, high-energy synchrotron X-ray diffraction (XRD) was used to evaluate Alloy 617 and Alloy 230, both of which are top candidate structural materials for the Very-High-Temperature Reactor (VHTR). Uniaxial tensile experiments using in-situ high-energy X-ray exposure showed the substantial advantages of this synchrotron technique. First, the small volume fractions of carbides, e.g. ∼6% of M6C in Alloy 230, which are difficult to observe using lab-based X-ray machines or neutron scattering facilities, were successfully examined using high-energy X-ray diffraction. Second, the loading processes of the austenitic matrix and carbides were separately studied by analyzing their respective lattice strain evolutions. In the present study, the focus was placed on Alloy 230. Although the Bragg reflections from the γ matrix behave differently, the lattice strain measured from these reflections responds linearly to external applied stress. In contrast, the lattice strain evolution for carbides is more complicated. During the transition from the elastic to the plastic regime, carbide particles experience a dramatic loading process, and their internal stress rapidly reaches the maximum value that can be withstood. The internal stress for the particles then decreases slowly with increasing applied stress. This indicates a continued particle fracture process during plastic deformations of the γ matrix. The study showed that high-energy synchrotron X-ray radiation, as a non-destructive technique for in-situ measurement, can be applied to ongoing material research for nuclear applications.

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Merolle, L., E. Malucelli, M. Fratini, A. Gianoncelli, A. Notargiacomo, C. Cappadone, G. Farruggia et al. „Repeatability and reproducibility of intracellular molar concentration assessed by synchrotron-based x-ray fluorescence microscopy“. In XRM 2014: Proceedings of the 12th International Conference on X-Ray Microscopy. AIP Publishing LLC, 2016. http://dx.doi.org/10.1063/1.4937526.

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Aziz, Ikmal Hakem, Mohd Mustafa Al Bakri Abdullah, Arif Anuar Salleh, Emy Aizat Azimi und Jitrin Chaiprapa. „Element distribution in slag geopolymer using synchrotron based micro-x-ray fluorescence (µ-XRF)“. In APPLIED PHYSICS OF CONDENSED MATTER (APCOM 2019). AIP Publishing, 2019. http://dx.doi.org/10.1063/1.5118068.

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Sabeena, M., S. Murugesan, R. Mythili, A. K. Sinha, M. N. Singh, M. Vijayalakshmi und S. K. Deb. „Influence of Mo in β phase stability of Ti- Mo system: Synchrotron based XRD studies“. In SOLID STATE PHYSICS: Proceedings of the 58th DAE Solid State Physics Symposium 2013. AIP Publishing LLC, 2014. http://dx.doi.org/10.1063/1.4872514.

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Carl, Matthew, Victoria Garcia, Brian Van Doren, Scott Schlegel und Marcus Young. „Effect of Heat Treating on Precipitate Phases in NiTiHf“. In ASME 2015 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/smasis2015-8957.

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Recently, NiTiHf-based HTSMAs have been shown to exhibit unique precipitation and mechanical behavior. In this study, a rolled plate of NiTiHf HTSMA was homogenized and heat treated at various times and temperatures and characterized using a barrage of analytical techniques including high-energy synchrotron X-ray diffraction (SR-XRD). Neither homogenization nor any of heat treatments studied significantly affect the austenitic or martensitic transformation temperatures. H-phase was observed to precipitate at heat treating times below 30 minutes and then to subsequently dissolve away for times of 30 minutes and above. The presence of H-phase dramatically increases the material strength by almost a factor of 2, Lastly, an over-aging effect occurs with increasing time due to the disappearance of the H-phase.

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Trivedi, Ayushi, P. N. Rao, R. J. Choudhary und M. K. Tiwari. „Determination of arsenic diffusion in PLD grown ZnO thin films using synchrotron based XRR-GIXRF measurements“. In DAE SOLID STATE PHYSICS SYMPOSIUM 2018. AIP Publishing, 2019. http://dx.doi.org/10.1063/1.5113154.

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Schleicher, N., U. Kramar, S. Norra, V. Dietze, U. Kaminski, K. Cen, Y. Yu, Melissa Denecke und Clive T. Walker. „μ-Scale Variations Of Elemental Composition In Individual Atmospheric Particles By Means Of Synchrotron Radiation Based μ-XRF Analysis“. In X-RAY OPTICS AND MICROANALYSIS: Proceedings of the 20th International Congress. AIP, 2010. http://dx.doi.org/10.1063/1.3399245.

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Alsecz, A., J. Osa´n, J. Pa´lfalvi, I. Sajo´, Z. Ma´the´, R. Simon, Sz To¨ro¨k und G. Falkenberg. „Study of the Oxidation State of Arsenic and Uranium in Individual Particles From Uranium Mine Tailings, Hungary“. In The 11th International Conference on Environmental Remediation and Radioactive Waste Management. ASMEDC, 2007. http://dx.doi.org/10.1115/icem2007-7354.

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Uranium ore mining and milling have been terminated in the Mecsek Mountains (southwest Hungary) in 1997. Mine tailings ponds are located between two important water bases, which are resources of the drinking water of the city of Pe´cs and the neighbouring villages. The average U concentration of the tailings material is 71.73 μg/g, but it is inhomogeneous. Some microscopic particles contain orders of magnitude more U than the rest of the tailings material. Other potentially toxic elements are As and Pb of which chemical state is important to estimate mobility, because in mobile form they can risk the water basis and the public health. Individual U-rich particles were selected with solid state nuclear track detector (SSNTD) and after localisation the particles were investigated by synchrotron radiation based microanalytical techniques. The distribution of elements over the particles was studied by micro beam X-ray fluorescence (μ-XRF) and the oxidation state of uranium and arsenic was determined by micro X-ray absorption near edge structure (μ-XANES) spectroscopy. Some of the measured U-rich particles were chosen for studying the heterogeneity with μ-XRF tomography. Arsenic was present mainly in As(V) and uranium in U(VI) form in the original uranium ore particles, but in the mine tailings samples uranium was present mainly in the less mobile U(IV) form. Correlation was found between the oxidation state of As and U in the same analyzed particles. These results suggest that dissolution of uranium is not expected in short term period.

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Pinzani, M. Caterina Camerani, Britt-Marie Steenari und Oliver Lindqvist. „Direct Determination of Cadmium Speciation in MSW and Biomass Single Fly Ash Particles Using SR Based µ-XR Spectroscopy Techniques“. In 17th International Conference on Fluidized Bed Combustion. ASMEDC, 2003. http://dx.doi.org/10.1115/fbc2003-021.

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Cadmium is a toxic metal causing environmental concern in connection with utilization and land filling of ash. Knowledge about the chemical associations of Cd in ash is fundamental in the understanding of its solubility and leachability from the ash. In the work presented here, the content, distribution and chemical forms of Cd on/in individual Municipal Solid Waste (MSW) and biomass fly ash particles have been investigated in situ by Synchrotron Radiation induced μ-X-ray fluorescence, absorption spectrometry (XAS) and fluorescence tomography. These X-ray micro-beam techniques can be used to reveal spatially resolved information about structural and chemical properties of particles. The use of an excitation energy of 27 keV made it possible to detect trace metals, such as Cd at ppm levels, but also other elements, like Ca, K, Cl and Br. Absorption spectra of Cd in the energy range around the absorption edge of Cd (26.71 keV) were recorded for micron-sized spots of ash particles. Fluorescence tomography was then use to establish if Cd compounds are situated on the particle surface (i.e. most prone to leaching) or at some depth within the particle, where they might be more shielded from chemical attack by water. The measurements indicated Cd to be preferably concentrated in some small areas (“hot-spots”) with high concentration (up to 200 ppm) in MSW fly ash particles and in a homogeneous distribution over the whole particle surface in the case of biomass. Comparisons of XAS spectra of fly ashes and reference compounds showed Cd to be present in the oxidation state +2 and mainly as CdSO4, CdO and CdCl2. Although previous studies have indicated Cd to be enriched in the smaller-size ash particles, in this study Cd was found to be reasonably well distributed throughout all the particle sizes investigated. Based on the results obtained, possible reaction mechanisms involving Cd are suggested.

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