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Journal articles on the topic 'Tomographie en diffraction'

Author: Grafiati

Published: 4 June 2021

Last updated: 12 February 2022

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1

Duchene, B., and W. Tabbara. "Tomographie ultrasonore par diffraction." Revue de Physique Appliquée 20, no. 6 (1985): 299–304. http://dx.doi.org/10.1051/rphysap:01985002006029900.

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2

Mohammad-Djafari, A., and G. Demoment. "Tomographie de diffraction et synthèse de Fourier à maximum d'entropie." Revue de Physique Appliquée 22, no. 2 (1987): 153–67. http://dx.doi.org/10.1051/rphysap:01987002202015300.

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3

Neichel, Benoit, and Gérard Rousset. "La tomographie de l’atmosphère au service de l’astrophysique." Photoniques, no. 95 (January 2019): 29–33. http://dx.doi.org/10.1051/photon/20199529.

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Depuis près de 30 ans, l’optique adaptative (OA) se développe en astronomie pour corriger les effets de la turbulence atmosphérique et recouvrer la limite de diffraction des grands télescopes au sol. Récemment, les OAs grand champ avec étoiles laser s’appuyant sur la tomographie de l’atmosphère ont été démontrées dans plusieurs observatoires pour offrir une correction dans un champ de vue accru et une bonne couverture du ciel. Ces techniques sont aujourd’hui étendues pour satisfaire les besoins des extrêmement grands télescopes qui verront le jour au milieu des années 2020.

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4

Hamelin, B., P. Bastie, D. Richard, and A. Eiaazzouzi. "Imagerie 2D et 3D de matériaux monocristallins : topographie et tomographie en diffraction rayons X de très haute énergie." Journal de Physique IV (Proceedings) 118 (November 2004): 437–46. http://dx.doi.org/10.1051/jp4:2004118051.

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5

Vamvakeros, Antonios, Simon D. M. Jacques, Marco Di Michiel, et al. "Interlaced X-ray diffraction computed tomography." Journal of Applied Crystallography 49, no. 2 (2016): 485–96. http://dx.doi.org/10.1107/s160057671600131x.

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An X-ray diffraction computed tomography data-collection strategy that allows, post experiment, a choice between temporal and spatial resolution is reported. This strategy enables time-resolved studies on comparatively short timescales, or alternatively allows for improved spatial resolution if the system under study, or components within it, appear to be unchanging. The application of the method for studying an Mn–Na–W/SiO2 fixed-bed reactor in situ is demonstrated. Additionally, the opportunities to improve the data-collection strategy further, enabling post-collection tuning between statistical, temporal and spatial resolutions, are discussed. In principle, the interlaced scanning approach can also be applied to other pencil-beam tomographic techniques, like X-ray fluorescence computed tomography, X-ray absorption fine structure computed tomography, pair distribution function computed tomography and tomographic scanning transmission X-ray microscopy.

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Machnio, Piotr, Michał Ziemczonok, and Małgorzata Kujawińska. "Reconstruction enhancement via projection screening in holographic tomography." Photonics Letters of Poland 13, no. 2 (2021): 37. http://dx.doi.org/10.4302/plp.v13i2.1104.

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This paper presents an algorithm for automatic detection of erroneous amplitude and phase components of a sample’s optical field, acquired by a holographic tomograph with a limited angle of projection. By applying image processing methods and statistical analysis to find and remove unfit projections, the quality of tomographic reconstruction of a 3D refractive index distribution of an object is greatly improved. The proposed methods can find their application in preprocessing of data in holographic tomography. Full Text: PDF ReferencesA. Kuś, W. Krauze, P. L. Makowski, and M. Kujawińska, "Holographic tomography: hardware and software solutions for 3D quantitative biomedical imaging (Invited paper)", ETRI Journal, 41, 1 (2019). CrossRef V. Balasubramani et al., "Phase unwrapping in ICF target interferometric measurement via deep learning", Appl. Opt., 60, 10 (2021). CrossRef Y. Park, C. Depeursinge, and G. Popescu, "Quantitative phase imaging in biomedicine", Nature Photonics, 12, 10 (2018). CrossRef W. Krauze, P. Makowski, M. Kujawińska, and A. Kuś, "Generalized total variation iterative constraint strategy in limited angle optical diffraction tomography", Opt. Express, 24, 5 (2016). CrossRef D. Ryu et al., "A non-calorimetric approach for investigating the moisture-induced ageing of a pyrotechnic delay material using spectroscopies", Sci Rep, 9, 1 (2019). CrossRef B. S. Lipkin, Picture Processing and Psychopictorics. (Saint Louis, Elsevier Science 2014). DirectLink A. M. Taddese, N. Verrier, M. Debailleul, J.-B. Courbot, and O. Haeberlé, "Optimizing sample illumination scanning in transmission tomographic diffractive microscopy", Appl. Opt., 60, 6 (2021). CrossRef

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7

Huang, Yunsong, Dongliang Zhang, and Gerard T. Schuster. "Tomographic resolution limits for diffraction imaging." Interpretation 3, no. 1 (2015): SF15—SF20. http://dx.doi.org/10.1190/int-2014-0079.1.

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We derived formulas for the tomographic resolution limits [Formula: see text] of diffraction data. Resolution limits exhibited that diffractions can provide twice or more the tomographic resolution of specular reflections and therefore led to more accurate reconstructions of velocities between layers. Numerical simulations supported this claim in which the tomogram inverted from diffraction data was noticeably more resolved compared to that inverted from specular data. The specular synthetics were generated by sources on the surface, and the diffraction data were generated by buried diffractors. However, this advantage is nullified if the intensity and signal-to-noise ratio of the diffractions are much less than those of the pervasive specular reflections.

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8

Troyan, V. N., and G. A. Ryzhikov. "Diffraction tomography: Construction and interpretation of tomographic functionals." Journal of Mathematical Sciences 86, no. 3 (1997): 2773–86. http://dx.doi.org/10.1007/bf02355168.

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9

Aknoun, Sherazade, Benoit Wattellier, Pierre Bon, and Serge Monneret. "Tomographic Incoherent Phase Imaging, a Diffraction Tomography Alternative." Biophysical Journal 106, no. 2 (2014): 603a. http://dx.doi.org/10.1016/j.bpj.2013.11.3336.

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10

Shin, Hee Jung, Ram M. Narayanan, and Muralidhar Rangaswamy. "Ultrawideband Noise Radar Imaging of Impenetrable Cylindrical Objects Using Diffraction Tomography." International Journal of Microwave Science and Technology 2014 (December 24, 2014): 1–22. http://dx.doi.org/10.1155/2014/601659.

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Ultrawideband (UWB) waveforms achieve excellent spatial resolution for better characterization of targets in tomographic imaging applications compared to narrowband waveforms. In this paper, two-dimensional tomographic images of multiple scattering objects are successfully obtained using the diffraction tomography approach by transmitting multiple independent and identically distributed (iid) UWB random noise waveforms. The feasibility of using a random noise waveform for tomography is investigated by formulating a white Gaussian noise (WGN) model using spectral estimation. The analytical formulation of object image formation using random noise waveforms is established based on the backward scattering, and several numerical diffraction tomography simulations are performed in the spatial frequency domain to validate the analytical results by reconstructing the tomographic images of scattering objects. The final image of the object based on multiple transmitted noise waveforms is reconstructed by averaging individually formed images which compares very well with the image created using the traditional Gaussian pulse. Pixel difference-based measure is used to analyze and estimate the image quality of the final reconstructed tomographic image under various signal-to-noise ratio (SNR) conditions. Also, preliminary experiment setup and measurement results are presented to assess the validation of simulation results.

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11

Lauer, V. "New approach to optical diffraction tomography yielding a vector equation of diffraction tomography and a novel tomographic microscope." Journal of Microscopy 205, no. 2 (2002): 165–76. http://dx.doi.org/10.1046/j.0022-2720.2001.00980.x.

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12

Stewart, Andrew. "Combing electron diffraction techniques for structure solution." Acta Crystallographica Section A Foundations and Advances 70, a1 (2014): C369. http://dx.doi.org/10.1107/s2053273314096302.

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The last few years have seen a revolution in the field of 3D electron diffraction or diffraction tomography. We have moved from only acquiring a few low index zone axis patterns to full tomographic data sets recording all accessible areas of reciprocal space. These new larger data sets have made it easier for structure solution techniques such as direct methods from the x-ray world to be applied to the electron diffraction data for structure solution. While structure solution with tomographic electron diffraction is non trivial when compared to the x-ray case it is significantly easier than it was a few years ago. Mugnaioli et al. We are now in a situation where the most difficult and time consuming step can be the assignment of the space group to a data set. Electron diffraction has many advantages over the x-ray case in terms of the manner in which we can manipulate the electron beam. This allows the collection to convergent beam diffraction (CBD) or large angle convergent beam diffraction (LACBED) patterns, via the recently developed technique by Beanland et al. These techniques can make the assignment of space group significantly easier affair, and the path to structure solution a lot smoother. We will present the combination of data from tomographic, selected area (SA) and nano-beam (NBD) datasets, with diffraction from tomographic LACBED experiments where using the strengths of each technique can be leveraged for a much quicker route to structure solution.

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Baimpas, Nikolaos, Mengyin Xie, Christina Reinhard, and Alexander M. Korsunsky. "The application of geometry corrections for Diffraction Strain Tomography (DST) analysis of a Ni-base superalloy blade." Powder Diffraction 28, S2 (2013): S436—S447. http://dx.doi.org/10.1017/s0885715613000857.

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X-ray diffraction is commonly used for non-destructive and precise quantitative determination of internal strain distributions. In recent years tomographic imaging has also been established as a powerful tool for precise non-destructive evaluation of internal structure in materials offering submicron resolution 3D imaging of density distributions. “Diffraction Strain tomography” (DST) concept (Korsunsky, Vorster et al. 2006) has been introduced as a means of tomographic reconstruction of two-dimensional internal strain distributions. The application of this approach during in situ loading has been subsequently demonstrated (Korsunsky et al., 2011). In the present study, similar acquisition strategy was used for diffraction data collection from a Ni-base superalloy turbine blade fabricated by DMLS (Direct Metal Laser Sintering, also sometimes referred to as DLD, Direct Laser Deposition). The experiment was conducted on beamline I12 (JEEP) at Diamond Light Source, UK. Each location within the object was multiply “sampled” (i.e. diffraction patterns were collected containing its contribution) by incident X-ray beams travelling through the sample at different angles. The setup of the beamline also allowed to acquire simultaneously a conventional (absorption tomography) reconstruction of the sample shape. The aim of the experiment was to obtain detailed information about the sample shape, structure, and state. The interpretation of diffraction tomography data requires precise calibration of the sample detector distance at different rotations and positions across the sample, and subsequent application of corrections to remove geometry-induced strain aberrations.

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Lasaygues, P., D. Tanne, S. Mensah, and J. P. Lefebvre. "Circular Antenna for Breast Ultrasonic Diffraction Tomography." Ultrasonic Imaging 24, no. 3 (2002): 177–89. http://dx.doi.org/10.1177/016173460202400304.

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Compared to echography, which exploits only the reflected field, ultrasonic diffraction tomography improves image resolution by combining the total diffracted field. For breast cancer imaging, this improvement reinforces contrast between various breast tissues and structures by eliminating some interference phenomena such as speckle and then allowing parameterization of the images. Our work concerns the development of an experimental set-up for fast acquisition of the diffracted field and construction of two-dimensional tomographic images. For this purpose, we developed a multichannel ultrasound circular antenna with eight focused transducers.

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15

Wang, Dayong, Xiaoyu Jin, Jie Zhao, Yunxin Wang, Lu Rong, and John J. Healy. "Continuous-wave terahertz diffraction tomography for measuring three-dimensional refractive index maps." Chinese Optics Letters 19, no. 12 (2021): 123701. http://dx.doi.org/10.3788/col202119.123701.

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Santos, Luiz Alberto, Webe Joao Mansur, and George A. McMechan. "Tomography of diffraction-based focusing operators." GEOPHYSICS 77, no. 5 (2012): R217—R225. http://dx.doi.org/10.1190/geo2011-0392.1.

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Diffractions carry the same kinematic information provided by common focus point operators (CFPOs). Thus CFPO and diffraction time trajectories may be used separately, or combined into a single unified tomography for velocity analysis. Velocity estimation by tomography of CFPOs reduces the depth-velocity ambiguity compared to two-way time tomography. CFPO estimation is complicated where there are event discontinuities and diffractions. This problem is overcome by using the kinematic information in diffractions in near-offset common-offset gathers. The procedure is illustrated using synthetic data, and a single-channel field seismic profile from the Blake Ridge (off the east coast of the United States). The results show the effectiveness of the proposed method for estimation of velocity from single channel seismic data, and for refinement of the velocity field from multichannel data. Both applications are cost-competitive.

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17

Young, J. A. "Diffraction tomography applied to crosshole and VSP seismic data." Exploration Geophysics 20, no. 2 (1989): 169. http://dx.doi.org/10.1071/eg989169.

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Diffraction tomography is an approach to seismic inversion which is analogous to f-k migration. It differs from f-k migration in that it attempts to obtain a more quantitative rather than qualitative image of the Earth's subsurface. Diffraction tomography is based on the generalized projection-slice theorem which relates the scattered wave field to the Fourier spectrum of the scatterer. Factors such as the survey geometry and the source bandwidth determine the data coverage in the spatial Fourier domain which in turn determines the image resolution. Limited view-angles result in regions of the spatial Fourier domain with no data coverage, causing the solution to the tomographic reconstruction problem to be nonunique. The simplistic approach is to assume the missing samples are zero and perform a standard reconstruction but this can result in images with severe artefacts. Additional a priori information can be introduced to the problem in order to reduce the nonuniqueness and increase the stability of the reconstruction. This is the standard approach used in ray tomography but it is not commonly used in diffraction tomography applied to seismic data.This paper shows the application of diffraction tomography to crosshole and VSP seismic data. Using synthetic data, the effects on image resolution of the survey geometry and the finite source bandwidth are examined and techniques for improving image quality are discussed.

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18

Wu, Ru‐Shan, and M. Nafi Toksöz. "Diffraction tomography and multisource holography applied to seismic imaging." GEOPHYSICS 52, no. 1 (1987): 11–25. http://dx.doi.org/10.1190/1.1442237.

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Seismic tomography is emerging as an imaging method for determining subsurface structure. When the view‐angle coverage is limited and the scale of the medium inhomogeneities is comparable with the wavelength, as is often true in geophysical applications, the performance of ordinary ray tomography becomes poor. Other tomographic methods are needed to improve the imaging process. Here we study diffraction tomography and multisource holography and evaluate their performances for surface reflection profiling (SRP), vertical seismic profiling (VSP), and cross‐hole measurements. Theoretical formulations are derived for two‐dimensional geometry in terms of line sources along a source line and line receivers along a receiver line. The theory for diffraction tomography is based on the Born or Rytov approximation. The performances of diffraction tomography and multisource holography are evaluated by examining the information coverage in the spatial frequency domain and by numerical examples. Multisource holography, which is similar to Kirchhoff‐type migration, often gives distorted images of the object. This distortion causes long tails of the image in the case of SRP and a strong noise belt in the case of VSP and is due to incomplete and nonuniform coverage of the object spectrum. The filtering operation of diffraction tomography helps in correcting the nonuniform coverage (including duplication) of the object spectrum in the reconstruction process and therefore reduces the distortions. On the other hand, multisource holography is better suited for imaging sharp boundaries with large acoustic impedance contrasts since diffraction tomography is restricted, as presently formulated, to weak inhomogeneities. In addition, multisource holography has the flexibility to be used with an arbitrary number of sources (including a single source). Its sampling interval is not restricted by the Nyquist frequency. Numerical examples show that combined data sets (such as surface reflection data combined with VSP data, or cross‐hole data combined with surface data, etc.) improve the image quality.

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19

Kazantsev, Daniil, Ramona Duman, Armin Wagner, et al. "X-ray tomographic reconstruction and segmentation pipeline for the long-wavelength macromolecular crystallography beamline at Diamond Light Source." Journal of Synchrotron Radiation 28, no. 3 (2021): 889–901. http://dx.doi.org/10.1107/s1600577521003453.

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In this paper a practical solution for the reconstruction and segmentation of low-contrast X-ray tomographic data of protein crystals from the long-wavelength macromolecular crystallography beamline I23 at Diamond Light Source is provided. The resulting segmented data will provide the path lengths through both diffracting and non-diffracting materials as basis for analytical absorption corrections for X-ray diffraction data taken in the same sample environment ahead of the tomography experiment. X-ray tomography data from protein crystals can be difficult to analyse due to very low or absent contrast between the different materials: the crystal, the sample holder and the surrounding mother liquor. The proposed data processing pipeline consists of two major sequential operations: model-based iterative reconstruction to improve contrast and minimize the influence of noise and artefacts, followed by segmentation. The segmentation aims to partition the reconstructed data into four phases: the crystal, mother liquor, loop and vacuum. In this study three different semi-automated segmentation methods are experimented with by using Gaussian mixture models, geodesic distance thresholding and a novel morphological method, RegionGrow, implemented specifically for the task. The complete reconstruction-segmentation pipeline is integrated into the MPI-based data analysis and reconstruction framework Savu, which is used to reduce computation time through parallelization across a computing cluster and makes the developed methods easily accessible.

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20

Justice, J. H., A. A. Vassiliou, and D. T. Nguyen. "Geophysical diffraction tomography." Signal Processing 15, no. 3 (1988): 227–35. http://dx.doi.org/10.1016/0165-1684(88)90013-8.

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21

Wragg, David Stephen, Matthew G. O'Brien, Marco Di Michiel, and Francesca Lønstad-Bleken. "Rietveld analysis of computed tomography and its application to methanol to olefin reactor beds." Journal of Applied Crystallography 48, no. 6 (2015): 1719–28. http://dx.doi.org/10.1107/s1600576715017288.

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This article reports the creation of tomographic reconstructions giving three-dimensional data on the distribution of various structural features for SAPO-34 zeolite catalyst beds used in the commercially important methanol to olefin conversion process. The data were processed using parametric Rietveld refinement to treat entire slices of the tomograph as single refined data sets, allowing extraction of real structural parameters from all voxels of the reconstruction. This has the advantage over more traditional methods of X-ray diffraction computed tomography using peak intensities, that the structural parameters are independent of the intensity, meaning that information can still be extracted from poor data sets: an example is shown where part of the sample was no longer in the beam during data collection. Reconstructions using several structural parameters are presented and the results compared. Analysis of the variation of the catalystcaxis (linked to the degree of deactivation in earlier work) shows small but significant three-dimensional variations in the degree of deactivation with patterns which depend on the silicon content of the catalyst. Average data for the tomographic slices compare well with the results of earlieroperandotwo-dimensional reactor scanning experiments.

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Becher, Johannes, Sebastian Weber, Dario Ferreira Sanchez, et al. "Sample Environment for Operando Hard X-ray Tomography—An Enabling Technology for Multimodal Characterization in Heterogeneous Catalysis." Catalysts 11, no. 4 (2021): 459. http://dx.doi.org/10.3390/catal11040459.

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Structure–activity relations in heterogeneous catalysis can be revealed through in situ and operando measurements of catalysts in their active state. While hard X-ray tomography is an ideal method for non-invasive, multimodal 3D structural characterization on the micron to nm scale, performing tomography under controlled gas and temperature conditions is challenging. Here, we present a flexible sample environment for operando hard X-ray tomography at synchrotron radiation sources. The setup features are discussed, with demonstrations of operando powder X-ray diffraction tomography (XRD-CT) and energy-dispersive tomographic X-ray absorption spectroscopy (ED-XAS-CT). Catalysts for CO2 methanation and partial oxidation of methane are shown as case studies. The setup can be adapted for different hard X-ray microscopy, spectroscopy, or scattering synchrotron radiation beamlines, is compatible with absorption, diffraction, fluorescence, and phase-contrast imaging, and can operate with scanning focused beam or full-field acquisition mode. We present an accessible methodology for operando hard X-ray tomography studies, which offer a unique source of 3D spatially resolved characterization data unavailable to contemporary methods.

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23

Gürsoy, Dogˇa, Francesco De Carlo, Xianghui Xiao, and Chris Jacobsen. "TomoPy: a framework for the analysis of synchrotron tomographic data." Journal of Synchrotron Radiation 21, no. 5 (2014): 1188–93. http://dx.doi.org/10.1107/s1600577514013939.

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Analysis of tomographic datasets at synchrotron light sources (including X-ray transmission tomography, X-ray fluorescence microscopy and X-ray diffraction tomography) is becoming progressively more challenging due to the increasing data acquisition rates that new technologies in X-ray sources and detectors enable. The next generation of synchrotron facilities that are currently under design or construction throughout the world will provide diffraction-limited X-ray sources and are expected to boost the current data rates by several orders of magnitude, stressing the need for the development and integration of efficient analysis tools. Here an attempt to provide a collaborative framework for the analysis of synchrotron tomographic data that has the potential to unify the effort of different facilities and beamlines performing similar tasks is described in detail. The proposed Python-based framework is open-source, platform- and data-format-independent, has multiprocessing capability and supports procedural programming that many researchers prefer. This collaborative platform could affect all major synchrotron facilities where new effort is now dedicated to developing new tools that can be deployed at the facility for real-time processing, as well as distributed to users for off-site data processing.

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24

Lenthe, William C., McLean P. Echlin, Andreas Trenkle, Melanie Syha, Peter Gumbsch, and Tresa M. Pollock. "Quantitative voxel-to-voxel comparison of TriBeam and DCT strontium titanate three-dimensional data sets." Journal of Applied Crystallography 48, no. 4 (2015): 1034–46. http://dx.doi.org/10.1107/s1600576715009231.

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Recently, techniques for the acquisition of three-dimensional tomographic and four-dimensional time-resolved data sets have emerged, allowing for the analysis of mm3volumes of material with nm-scale resolution. The ability to merge multi-modal data sets acquiredviamultiple techniques for the quantitative analysis of structure, chemistry and phase information is still a significant challenge. Large three-dimensional data sets have been acquired by time-resolved diffraction contrast tomography (DCT) and a new TriBeam tomography technique with high spatial resolution to address grain growth in strontium titanate. A methodology for combining three-dimensional tomographic data has been developed. Algorithms for the alignment of orientation reference frames, unification of sampling grids and automated grain matching have been integrated, and the resulting merged data set permits the simultaneous analysis of all tomographic data on a voxel-by-voxel and grain-by-grain basis. Quantitative analysis of merged data sets collected using DCT and TriBeam tomography shows that the spatial resolution of the DCT technique is limited near grain boundaries and the sample edge, resolving grains down to 10 µm diameter for the reconstruction method used. While the TriBeam technique allows for higher-resolution analysis of boundary plane location, it is a destructive tomography approach and can only be employed at the conclusion of a four-dimensional experiment.

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Pratt, R. Gerhard, and M. H. Worthington. "The application of diffraction tomography to cross‐hole seismic data." GEOPHYSICS 53, no. 10 (1988): 1284–94. http://dx.doi.org/10.1190/1.1442406.

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Previously published equations for diffraction tomography do not solve the “two and one‐half dimensional problem” (point source illumination of two‐dimensional geology) if sources and receivers are confined to linear arrays. In spite of this lack of a formal solution, useful images can be formed by the application of two‐dimensional formulas to such problems. The estimation of difference fields, of crucial importance in diffraction tomography, reduces to the problem of estimating the source function. Using assumptions about the consistency of the source behavior, we extract the source function in a statistical fashion from cross‐hole data. Using this technique, the difference fields are computed directly from the recorded wave fields for two experiments and diffraction tomographic images are obtained. In the first experiment, the data are generated using a two‐dimensional finite‐difference modeling algorithm. In the second, a physical scale model of a crosshole experiment is performed in an ultrasonic modeling tank. Images are obtained within both the first Born and Rytov’s approximation. Our results indicate that Rytov’s approximation achieves good resolution of the lower wavenumber components of the object, whereas the first Born approximation is more successful where the object is discontinuous.

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26

Witten, Alan J. "Seismic Reflection Diffraction Tomography." Journal of Environmental and Engineering Geophysics 1, no. 3 (1996): 205–13. http://dx.doi.org/10.4133/jeeg1.3.205.

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Bouwens, Arno, and Theo Lasser. "White-light diffraction tomography." Nature Photonics 8, no. 3 (2014): 173–74. http://dx.doi.org/10.1038/nphoton.2014.44.

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28

Jung, JaeHwang, Kyoohyun Kim, Jonghee Yoon, and YongKeun Park. "Hyperspectral optical diffraction tomography." Optics Express 24, no. 3 (2016): 2006. http://dx.doi.org/10.1364/oe.24.002006.

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29

King, A., P. Reischig, J. Adrien, S. Peetermans, and W. Ludwig. "Polychromatic diffraction contrast tomography." Materials Characterization 97 (November 2014): 1–10. http://dx.doi.org/10.1016/j.matchar.2014.07.026.

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Gemmi, Mauro, Mari Grazia Immacolata La Placa, Athanassios Galanis, Edgar F. Rauch, and Stavros Nicolopoulos. "Fast electron diffraction tomography." Acta Crystallographica Section A Foundations and Advances 71, a1 (2015): s104. http://dx.doi.org/10.1107/s2053273315098472.

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Devaney, Anthony J. "Acoustic wave diffraction tomography." Journal of the Acoustical Society of America 110, no. 5 (2001): 2659. http://dx.doi.org/10.1121/1.4777061.

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Mensah, Serge, and Robert Ferriere. "Near-Field Diffraction Tomography." Ultrasonic Imaging 24, no. 1 (2002): 13–24. http://dx.doi.org/10.1177/016173460202400102.

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Roberts, B. A., and A. C. Kak. "Reflection Mode Diffraction Tomography." Ultrasonic Imaging 7, no. 4 (1985): 300–320. http://dx.doi.org/10.1177/016173468500700403.

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Gemmi, Mauro, Maria G. I. La Placa, Athanassios S. Galanis, Edgar F. Rauch, and Stavros Nicolopoulos. "Fast electron diffraction tomography." Journal of Applied Crystallography 48, no. 3 (2015): 718–27. http://dx.doi.org/10.1107/s1600576715004604.

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A fast and fully automatic procedure for collecting electron diffraction tomography data is presented. In the case of a very stable goniometer it is demonstrated how, by variation of the tilting speed and the CCD detector parameters, it is possible to obtain fully automatic precession-assisted electron diffraction tomography data collections, rotation electron diffraction tomography data collections or new integrated electron diffraction tomography data collections, in which the missing wedge of the reciprocal space between the patterns is recorded by longer exposures during the crystal tilt. It is shown how automatic data collection of limited tilt range can be used to determine the unit-cell parameters, while data of larger tilt range are suitable to solve the crystal structureabinitiowith direct methods. The crystal structure of monoclinic MgMoO4has been solved in this way as a test structure. In the case where the goniometer is not stable enough to guarantee a steady position of the crystal over large tilt ranges, an automatic method for tracking the crystal during continuous rotation of the sample is proposed.

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Lionheart, W. R. B., and P. J. Withers. "Diffraction tomography of strain." Inverse Problems 31, no. 4 (2015): 045005. http://dx.doi.org/10.1088/0266-5611/31/4/045005.

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Tsihrintzis, George A., and Anthony J. Devaney. "Stochastic geophysical diffraction tomography." International Journal of Imaging Systems and Technology 5, no. 3 (1994): 239–42. http://dx.doi.org/10.1002/ima.1850050307.

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Putkunz, C. T., M. A. Pfeifer, A. G. Peele, et al. "Fresnel coherent diffraction tomography." Optics Express 18, no. 11 (2010): 11746. http://dx.doi.org/10.1364/oe.18.011746.

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38

Doornbos, Durk J. "Diffraction and seismic tomography." Geophysical Journal International 108, no. 1 (1992): 256–66. http://dx.doi.org/10.1111/j.1365-246x.1992.tb00854.x.

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39

Lehman, Sean K., and Stephen J. Norton. "Radial reflection diffraction tomography." Journal of the Acoustical Society of America 116, no. 4 (2004): 2158–72. http://dx.doi.org/10.1121/1.1785651.

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Lehman, Sean K., and Stephen J. Norton. "Radial reflection diffraction tomography." Journal of the Acoustical Society of America 120, no. 5 (2006): 3025. http://dx.doi.org/10.1121/1.4787117.

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Roberts, B. "Reflection mode diffraction tomography." Ultrasonic Imaging 7, no. 3 (1985): 300–320. http://dx.doi.org/10.1016/0161-7346(85)90009-4.

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42

Vamvakeros, Antonios, Simon D. M. Jacques, Marco Di Michiel, et al. "Removing multiple outliers and single-crystal artefacts from X-ray diffraction computed tomography data." Journal of Applied Crystallography 48, no. 6 (2015): 1943–55. http://dx.doi.org/10.1107/s1600576715020701.

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This paper reports a simple but effective filtering approach to deal with single-crystal artefacts in X-ray diffraction computed tomography (XRD-CT). In XRD-CT, large crystallites can produce spots on top of the powder diffraction rings, which, after azimuthal integration and tomographic reconstruction, lead to line/streak artefacts in the tomograms. In the simple approach presented here, the polar transform is taken of collected two-dimensional diffraction patterns followed by directional median/mean filtering prior to integration. Reconstruction of one-dimensional diffraction projection data sets treated in such a way leads to a very significant improvement in reconstructed image quality for systems that exhibit powder spottiness arising from large crystallites. This approach is not computationally heavy which is an important consideration with big data sets such as is the case with XRD-CT. The method should have application to two-dimensional X-ray diffraction data in general where such spottiness arises.

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Bakhtiari Rad, Parsa, Benjamin Schwarz, Dirk Gajewski, and Claudia Vanelle. "Common-reflection-surface-based prestack diffraction separation and imaging." GEOPHYSICS 83, no. 1 (2018): S47—S55. http://dx.doi.org/10.1190/geo2016-0445.1.

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Diffraction imaging can lead to high-resolution characterization of small-scale subsurface structures. A key step of diffraction imaging and tomography is diffraction separation and enhancement, especially in the full prestack data volume. We have considered point diffractors and developed a robust and fully data-driven workflow for prestack diffraction separation based on wavefront attributes, which are determined using the common-reflection-surface (CRS) method. In the first of two steps, we apply a zero-offset-based extrapolation operator for prestack diffraction separation, which combines the robustness and stability of the zero-offset CRS processing with enhanced resolution and improved illumination of the finite-offset CRS processing. In the second step, when the finite-offset diffracted events are separated, we apply a diffraction-based time migration velocity model building that provides high-quality diffraction velocity spectra. Applications of the new workflow to 2D/3D complex synthetic data confirm the superiority of prestack diffraction separation over the poststack method as well as the high potential of diffractions for improved time imaging.

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44

Miao, John. "Beyond Crystallography: Coherent Diffraction Imaging and Atomic Resolution Electron Tomography." Acta Crystallographica Section A Foundations and Advances 70, a1 (2014): C5. http://dx.doi.org/10.1107/s205327331409994x.

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The discovery and interpretation of X-ray diffraction from crystals by von Laue, Henry and Lawrence Bragg about a century ago marked the beginning of a new era for visualizing the three-dimensional (3D) atomic structures in crystals. In 1999, the methodology of X-ray crystallography was extended to allow the structure determination of non-crystalline specimens, which is known as coherent diffraction imaging (CDI) or lensless imaging. In CDI, the diffraction pattern of a non-crystalline sample or a nanocrystal is first measured and then directly phased to obtain an image. The well-known phase problem is solved by combining the oversampling method with iterative algorithms. In the first part of the talk, I will present the principle of CDI and illustrate some applications using synchrotron radiation and X-ray free electron lasers (XFELs). In the second part of the talk, I will present a general tomographic method for determining the 3D local structure of materials at atomic resolution. By combining scanning transmission electron microscopy (STEM) with a novel data acquisition and image reconstruction method known as equally sloped tomography (EST), we achieve electron tomography at 2.4 Å resolution and observe nearly all the atoms in a multiply-twinned Pt nanoparticle. We find the existence of atomic steps at 3D twin boundaries of the Pt nanoparticle and, for the first time, image the 3D core structure of edge and screw dislocations in materials at atomic resolution. We expect this atomic resolution electron tomography method to find application in solid state physics, materials sciences, nanoscience, chemistry and biology.

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Gbur, Greg, and Emil Wolf. "Relation between computed tomography and diffraction tomography." Journal of the Optical Society of America A 18, no. 9 (2001): 2132. http://dx.doi.org/10.1364/josaa.18.002132.

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Chushkin, Y., F. Zontone, E. Lima, et al. "Three-dimensional coherent diffractive imaging on non-periodic specimens at the ESRF beamline ID10." Journal of Synchrotron Radiation 21, no. 3 (2014): 594–99. http://dx.doi.org/10.1107/s1600577514003440.

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The progress of tomographic coherent diffractive imaging with hard X-rays at the ID10 beamline of the European Synchrotron Radiation Facility is presented. The performance of the instrument is demonstrated by imaging a cluster of Fe2P magnetic nanorods at 59 nm 3D resolution by phasing a diffraction volume measured at 8 keV photon energy. The result obtained shows progress in three-dimensional imaging of non-crystalline samples in air with hard X-rays.

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Ladas, K. T., and A. J. Devaney. "Application of An Art Algorithm in an Experimental Study of Ultrasonic Diffraction Tomography." Ultrasonic Imaging 15, no. 1 (1993): 48–58. http://dx.doi.org/10.1177/016173469301500105.

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This paper describes results obtained using a recently developed Algebraic Reconstruction Technique (ART) for diffraction tomography on experimental data obtained from an ultrasound scanner built by Norwave Development A.S. of Oslo, Norway. The test objects (phantoms) employed in the study are low contrast cylindrical rods made out of agar with dimensions comparable to the wavelength of the incident wavefield. The reconstructions obtained from the ART algorithm are compared to the ones obtained from the filtered backpropagation algorithm. It is determined that the ART algorithm out performs the filtered backpropagation algorithm for cases where data from only a small number of tomographic experiments are available.

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Heacock, B., D. Sarenac, D. G. Cory, et al. "Neutron sub-micrometre tomography from scattering data." IUCrJ 7, no. 5 (2020): 893–900. http://dx.doi.org/10.1107/s2052252520010295.

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Neutrons are valuable probes for various material samples across many areas of research. Neutron imaging typically has a spatial resolution of larger than 20 µm, whereas neutron scattering is sensitive to smaller features but does not provide a real-space image of the sample. A computed-tomography technique is demonstrated that uses neutron-scattering data to generate an image of a periodic sample with a spatial resolution of ∼300 nm. The achieved resolution is over an order of magnitude smaller than the resolution of other forms of neutron tomography. This method consists of measuring neutron diffraction using a double-crystal diffractometer as a function of sample rotation and then using a phase-retrieval algorithm followed by tomographic reconstruction to generate a map of the sample's scattering-length density. Topological features found in the reconstructions are confirmed with scanning electron micrographs. This technique should be applicable to any sample that generates clear neutron-diffraction patterns, including nanofabricated samples, biological membranes and magnetic materials, such as skyrmion lattices.

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Vamvakeros, A., A. A. Coelho, D. Matras, et al. "DLSR: a solution to the parallax artefact in X-ray diffraction computed tomography data." Journal of Applied Crystallography 53, no. 6 (2020): 1531–41. http://dx.doi.org/10.1107/s1600576720013576.

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A new tomographic reconstruction algorithm is presented, termed direct least-squares reconstruction (DLSR), which solves the well known parallax problem in X-ray-scattering-based experiments. The parallax artefact arises from relatively large samples where X-rays, scattered from a scattering angle 2θ, arrive at multiple detector elements. This phenomenon leads to loss of physico-chemical information associated with diffraction peak shape and position (i.e. altering the calculated crystallite size and lattice parameter values, respectively) and is currently the major barrier to investigating samples and devices at the centimetre level (scale-up problem). The accuracy of the DLSR algorithm has been tested against simulated and experimental X-ray diffraction computed tomography data using the TOPAS software.

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Huang, Zhi-Feng, Ke-Jun Kang, Zheng Li, et al. "Direct computed tomographic reconstruction for directional-derivative projections of computed tomography of diffraction enhanced imaging." Applied Physics Letters 89, no. 4 (2006): 041124. http://dx.doi.org/10.1063/1.2219405.

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