scholarly journals Maximum a posteriori estimation of crystallographic phases in X-ray diffraction tomography

2015 ◽  
Vol 373 (2043) ◽  
pp. 20140392 ◽  
Author(s):  
Doĝa Gürsoy ◽  
Tekin Biçer ◽  
Jonathan D. Almer ◽  
Raj Kettimuthu ◽  
Stuart R. Stock ◽  
...  
Keyword(s):  
National Laboratory ◽  
Spinous Process ◽  
Argonne National Laboratory ◽  
Three Dimensional ◽  
Polycrystalline Materials ◽  
Reconstruction Method ◽  
Diffraction Tomography ◽  
A Posteriori ◽  
X Ray Diffraction ◽  
X Ray

A maximum a posteriori approach is proposed for X-ray diffraction tomography for reconstructing three-dimensional spatial distribution of crystallographic phases and orientations of polycrystalline materials. The approach maximizes the a posteriori density which includes a Poisson log-likelihood and an a priori term that reinforces expected solution properties such as smoothness or local continuity. The reconstruction method is validated with experimental data acquired from a section of the spinous process of a porcine vertebra collected at the 1-ID-C beamline of the Advanced Photon Source, at Argonne National Laboratory. The reconstruction results show significant improvement in the reduction of aliasing and streaking artefacts, and improved robustness to noise and undersampling compared to conventional analytical inversion approaches. The approach has the potential to reduce data acquisition times, and significantly improve beamtime efficiency.

High Resolution Synchrotron X-Ray Diffraction Tomography Of Large-Grained Samples

1996 ◽  
Vol 437 ◽  
Author(s):  
D.P. Piotrowski ◽  
S.R. Stock ◽  
A. Guvenilir ◽  
J.D. Haase ◽  
Z.U. Rek
Keyword(s):  
Spatial Distribution ◽  
High Resolution ◽  
Three Dimensional ◽  
Polycrystalline Materials ◽  
Diffraction Tomography ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Image Storage ◽  
X Ray ◽  
Dimensional Distribution

AbstractIn order to understand the macroscopic response of polycrystalline structural materials to loading, it is frequently essential to know the spatial distribution of strain as well as the variation of micro-texture on the scale of 100 μm. The methods must be nondestructive, however, if the three-dimensional evolution of strain is to be studied. This paper describes an approach to high resolution synchrotron x-ray diffraction tomography of polycrystalline materials. Results from model samples of randomly-packed, millimeter-sized pieces of Si wafers and of similarly sized single-crystal Al blocks have been obtained which indicate that polychromatic beams collimated to 30 μm diameter can be used to determine the depth of diffracting volume elements within ± 70 μm. The variation in the two-dimensional distribution of diffracted intensity with changing sample to detector separation is recorded on image storage plates and used to infer the depth of diffracting volume elements.

High Resolution Synchrotron X-Ray Diffraction Tomography of Polycrystalline Samples

1994 ◽  
Vol 375 ◽  
Author(s):  
S. R. Stock ◽  
A. Guvenilir ◽  
D. P. Piotrowski ◽  
Z. U. Rek
Keyword(s):  
Spatial Distribution ◽  
High Resolution ◽  
Three Dimensional ◽  
Compact Tension ◽  
Polycrystalline Materials ◽  
Diffraction Tomography ◽  
X Ray Diffraction ◽  
Image Storage ◽  
X Ray ◽  
Nondestructive Measurements

AbstractThe macroscopic response of polycrystalline materials to loading depends on both the spatial distribution of strain and the variation of microtexture on the scale of 100 μm. Nondestructive measurements are needed if the three-dimensional evolution of strain is to be studied. This paper describes approaches for high resolution synchrotron polychromatic x-ray diffraction tomography of polycrystalline materials. Preliminary experiments are reported on partially cracked compact tension samples of Al-Li 2090 and on model samples of randomly-packed, millimeter-sized pieces of Si wafers. Polychromatic beams collimated to 100 μm diameter have been used, and the distribution of diffracted intensity has been collected on high resolution x-ray film as well as on image storage plates. The depths of diffracting volume elements are determined from the changes in the spatial distribution of diffracted intensity with varying sample to detector separation.

scholarly journals Reconstructing intragranular strain fields in polycrystalline materials from scanning 3DXRD data

2020 ◽  
Vol 53 (2) ◽  
pp. 314-325 ◽  
Author(s):  
N. Axel Henningsson ◽  
Stephen A. Hall ◽  
Jonathan P. Wright ◽  
Johan Hektor
Keyword(s):  
Three Dimensional ◽  
Polycrystalline Materials ◽  
Reconstruction Method ◽  
X Ray Diffraction ◽  
Reconstruction Accuracy ◽  
Strain Fields ◽  
Spatial Properties ◽  
Reconstruction Methods ◽  
Reconstruction Quality ◽  
Made In

Two methods for reconstructing intragranular strain fields are developed for scanning three-dimensional X-ray diffraction (3DXRD). The methods are compared with a third approach where voxels are reconstructed independently of their neighbours [Hayashi, Setoyama & Seno (2017). Mater. Sci. Forum, 905, 157–164]. The 3D strain field of a tin grain, located within a sample of approximately 70 grains, is analysed and compared across reconstruction methods. Implicit assumptions of sub-problem independence, made in the independent voxel reconstruction method, are demonstrated to introduce bias and reduce reconstruction accuracy. It is verified that the two proposed methods remedy these problems by taking the spatial properties of the inverse problem into account. Improvements in reconstruction quality achieved by the two proposed methods are further supported by reconstructions using synthetic diffraction data.

scholarly journals PolyProc: A Modular Processing Pipeline for X-ray Diffraction Tomography

2019 ◽  
Vol 8 (3) ◽  
pp. 388-399 ◽  
Author(s):  
Jiwoong Kang ◽  
Ning Lu ◽  
Issac Loo ◽  
Nancy Senabulya ◽  
Ashwin J. Shahani
Keyword(s):  
Three Dimensional ◽  
Valuable Insight ◽  
Diffraction Tomography ◽  
Computationally Efficient ◽  
X Ray Diffraction ◽  
Orientation Data ◽  
Bulk Specimen ◽  
X Ray ◽  
Data Alignment ◽  
And Performance

Abstract Direct imaging of three-dimensional microstructure via X-ray diffraction-based techniques gives valuable insight into the crystallographic features that influence materials properties and performance. For instance, X-ray diffraction tomography provides information on grain orientation, position, size, and shape in a bulk specimen. As such techniques become more accessible to researchers, demands are placed on processing the datasets that are inherently “noisy,” multi-dimensional, and multimodal. To fulfill this need, we have developed a one-of-a-kind function package, PolyProc, that is compatible with a range of data shapes, from planar sections to time-evolving and three-dimensional orientation data. Our package comprises functions to import, filter, analyze, and visualize the reconstructed grain maps. To accelerate the computations in our pipeline, we harness computationally efficient approaches: for instance, data alignment is done via genetic optimization; grain tracking through the Hungarian method; and feature-to-feature correlation through k-nearest neighbors algorithm. As a proof-of-concept, we test our approach in characterizing the grain texture, topology, and evolution in a polycrystalline Al–Cu alloy undergoing coarsening.

scholarly journals Novel silica stabilization method for the analysis of fine nanocrystals using coherent X-ray diffraction imaging

2016 ◽  
Vol 23 (4) ◽  
pp. 953-958 ◽  
Author(s):  
Marianne Monteforte ◽  
Ana K. Estandarte ◽  
Bo Chen ◽  
Ross Harder ◽  
Michael H. Huang ◽  
...  
Keyword(s):  
National Laboratory ◽  
Argonne National Laboratory ◽  
Three Dimensional ◽  
High Energy ◽  
Silica Matrix ◽  
Stabilization Method ◽  
X Ray ◽  
Novel Device ◽  
Powerful Analytical Tool ◽  
Diffraction Imaging

High-energy X-ray Bragg coherent diffraction imaging (BCDI) is a well established synchrotron-based technique used to quantitatively reconstruct the three-dimensional morphology and strain distribution in nanocrystals. The BCDI technique has become a powerful analytical tool for quantitative investigations of nanocrystals, nanotubes, nanorods and more recently biological systems. BCDI has however typically failed for fine nanocrystals in sub-100 nm size regimes – a size routinely achievable by chemical synthesis – despite the spatial resolution of the BCDI technique being 20–30 nm. The limitations of this technique arise from the movement of nanocrystals under illumination by the highly coherent beam, which prevents full diffraction data sets from being acquired. A solution is provided here to overcome this problem and extend the size limit of the BCDI technique, through the design of a novel stabilization method by embedding the fine nanocrystals into a silica matrix. Chemically synthesized FePt nanocrystals of maximum dimension 20 nm and AuPd nanocrystals in the size range 60–65 nm were investigated with BCDI measurement at beamline 34-ID-C of the APS, Argonne National Laboratory. Novel experimental methodologies to elucidate the presence of strain in fine nanocrystals are a necessary pre-requisite in order to better understand strain profiles in engineered nanocrystals for novel device development.

Powder X-ray diffraction of capecitabine, C15H22FN3O6

2019 ◽  
Vol 34 (3) ◽  
pp. 282-283 ◽  
Author(s):  
James A. Kaduk ◽  
Amy M. Gindhart ◽  
Thomas N. Blanton
Keyword(s):  
Diffraction Data ◽  
Density Functional ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Acta Cryst ◽  
X Ray ◽  
Data Density ◽  
Structure Determinations

Capecitabine (Xeloda) is a chemotherapy drug used to treat breast, gastric, and colorectal cancers. Commercial capecitabine crystallizes in the orthorhombic space group P212121 (#19) with a = 5.20587(3), b = 9.52324(4), c = 34.79574(21) Å, V = 1725.062(12) Å3, and Z = 4. A reduced cell search in the Cambridge Structural Database (Groom C. R., Bruno, I. J., Lightfoot, M. P., and Ward, S. C. (2016) Crystallogr. Sect. B: Struct. Sci., Cryst. Eng. Mater.72, 171–179) yielded three previous structure determinations (Rohlicek, J., Husak, M., Gavenda, A., Jegorov, A., Kratochvil, B., and Fitch, A. (2016). Acta Cryst. Sect. E: Crystallgr. Commun.72, 879–880, BOVDUM; Malińska, M., Krzeczyński, P., Czerniec-Michalik, E., Trzcińska, K., Cmoch, P., Kutner, A., and Woźniak, K. (2014). J. Pharm. Sci.103, 587–593, BOVDUM01 and BOVDUM02), using synchrotron powder data and later single crystal data at two temperatures. In this work, the sample was ordered from United States Pharmacopeial Convention (lot # G0J205), and analyzed as-received. The room temperature (295 K) crystal structure was refined using synchrotron (λ = 0.413914 Å) powder diffraction data, density functional theory (DFT), and Rietveld refinement techniques. Hydrogen positions were included as part of the structure, and were re-calculated during the refinement. The diffraction data were collected on a beamline 11-BM at the Advanced Photon Source, Argonne National Laboratory and the powder X-ray diffraction pattern of the compound is provided. The agreement of the Rietveld-refined and DFT-optimized structures is poorest in the pentyl side chain, consistent with the disorder observed previously.

scholarly journals A comparative study of X-ray tomographic microscopy on shales at different synchrotron facilities: ALS, APS and SLS

2012 ◽  
Vol 20 (1) ◽  
pp. 172-180 ◽  
Author(s):  
Waruntorn Kanitpanyacharoen ◽  
Dilworth Y. Parkinson ◽  
Francesco De Carlo ◽  
Federica Marone ◽  
Marco Stampanoni ◽  
...  
Keyword(s):  
Data Quality ◽  
Light Source ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Three Dimensional ◽  
Objective Lens ◽  
Low Density ◽  
Experimental Conditions ◽  
X Ray ◽  
Volume Fractions

Synchrotron radiation X-ray tomographic microscopy (SRXTM) was used to characterize the three-dimensional microstructure, geometry and distribution of different phases in two shale samples obtained from the North Sea (sample N1) and the Upper Barnett Formation in Texas (sample B1). Shale is a challenging material because of its multiphase composition, small grain size, low but significant amount of porosity, as well as strong shape- and lattice-preferred orientation. The goals of this round-robin project were to (i) characterize microstructures and porosity on the micrometer scale, (ii) compare results measured at three synchrotron facilities, and (iii) identify optimal experimental conditions of high-resolution SRXTM for fine-grained materials. SRXTM data of these shales were acquired under similar conditions at the Advanced Light Source (ALS) of Lawrence Berkeley National Laboratory, USA, the Advanced Photon Source (APS) of Argonne National Laboratory, USA, and the Swiss Light Source (SLS) of the Paul Scherrer Institut, Switzerland. The data reconstruction of all datasets was handled under the same procedures in order to compare the data quality and determine phase proportions and microstructures. With a 10× objective lens the spatial resolution is approximately 2 µm. The sharpness of phase boundaries in the reconstructed data collected from the APS and SLS was comparable and slightly more refined than in the data obtained from the ALS. Important internal features, such as pyrite (high-absorbing), and low-density features, including pores, fractures and organic matter or kerogen (low-absorbing), were adequately segmented on the same basis. The average volume fractions of low-density features for sample N1 and B1 were estimated at 6.3 (6)% and 4.5 (4)%, while those of pyrite were calculated to be 5.6 (6)% and 2.0 (3)%, respectively. The discrepancy of data quality and volume fractions were mainly due to different types of optical instruments and varying technical set-ups at the ALS, APS and SLS.

Determining grain resolved stresses in polycrystalline materials using three-dimensional X-ray diffraction

2010 ◽  
Vol 43 (3) ◽  
pp. 539-549 ◽  
Author(s):  
Jette Oddershede ◽  
Søren Schmidt ◽  
Henning Friis Poulsen ◽  
Henning Osholm Sørensen ◽  
Jonathan Wright ◽  
...  
Keyword(s):  
Near Field ◽  
Three Dimensional ◽  
Polycrystalline Sample ◽  
Polycrystalline Materials ◽  
Interstitial Free ◽  
Outlier Rejection ◽  
X Ray Diffraction ◽  
Positional Accuracy ◽  
X Ray ◽  
Elastic Loading

An algorithm is presented for characterization of the grain resolved (type II) stress states in a polycrystalline sample based on monochromatic X-ray diffraction data. The algorithm is a robust 12-parameter-per-grain fit of the centre-of-mass grain positions, orientations and stress tensors including error estimation and outlier rejection. The algorithm is validated by simulations and by two experiments on interstitial free steel. In the first experiment, using only a far-field detector and a rotation range of 2 × 110°, 96 grains in one layer were monitored during elastic loading and unloading. Very consistent results were obtained, with mean resolutions for each grain of approximately 10 µm in position, 0.05° in orientation, and 8, 20 and 13 × 10−5in the axial, normal and shear components of the strain, respectively. The corresponding mean deviations in stress are 30, 50 and 15 MPa in the axial, normal and shear components, respectively, though some grains may have larger errors. In the second experiment, where a near-field detector was added, ∼2000 grains were characterized with a positional accuracy of 3 µm.

Toward the development of high resolution synchrotron x‐ray diffraction tomography of polycrystalline materials (abstract)

1996 ◽  
Vol 67 (9) ◽  
pp. 3358-3358
Author(s):  
Stuart R. Stock ◽  
D. P. Piotrowski ◽  
A. Guvenilir ◽  
C. R. Patterson ◽  
J. D. Haase ◽  
...  
Keyword(s):  
High Resolution ◽  
Polycrystalline Materials ◽  
Diffraction Tomography ◽  
X Ray Diffraction ◽  
X Ray
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