TY - JOUR A1 - Kupsch, Andreas A1 - Lange, Axel A1 - Hentschel, Manfred P. A1 - Jaenisch, Gerd-Rüdiger A1 - Kardjilov, N. A1 - Tötzke, C. A1 - Markötter, H. A1 - Hilger, A. A1 - Manke, I. T1 - X-ray compton line scan tomography JF - Materials testing N2 - The potentials of incoherent X-ray scattering (Compton) computed tomography (CT) are investigated. The imaging of materials of very different atomic number or density at once is generally a perpetual challenge for X-ray tomography or radiography. In a basic laboratory set-up for simultaneous perpendicular Compton scattering and direct beam attenuation tomography are conducted by single channel photon counting line scans. This results in asymmetric distortions of the projection profiles of the scattering CT data set. In a first approach, corrections of Compton scattering data by taking advantage of rotational symmetry yield tomograms without major geometric artefacts. A cylindrical sample composed of PE, PA, PVC, glass and wood demonstrates similar Compton contrast for all the substances, while the conventional absorption tomogram only reveals the two high order materials. Comparison to neutron tomography reveals astonishing similarities except for the glass component (without hydrogen). Therefore, Compton CT offers the potential to replace neutron tomography, which requires much more efforts. KW - X-ray compton scattering KW - Computed tomography KW - Neutron tomography PY - 2015 DO - https://doi.org/10.3139/120.110799 SN - 0025-5300 VL - 57 IS - 11-12 SP - 985 EP - 991 PB - Hanser CY - München AN - OPUS4-34963 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kupsch, Andreas A1 - Lange, Axel A1 - Hentschel, Manfred P. A1 - Lück, S. A1 - Schmidt, V. A1 - Grothausmann, R. A1 - Hilger, A. A1 - Manke, I. T1 - Missing wedge computed tomography by iterative algorithm DIRECTT JF - Journal of microscopy N2 - A strategy to mitigate typical reconstruction artefacts in missing wedge computed tomography is presented. These artefacts appear as elongations of reconstructed details along the mean direction (i.e. the symmetry centre of the projections). Although absent in standard computed tomography applications, they are most prominent in advanced electron tomography and also in special topics of X-ray and Neutron tomography under restricted geometric boundary conditions. We investigate the Performance of the DIRECTT (Direct Iterative Reconstruction of Computed Tomography Trajectories) algorithm to reduce the directional artefacts in standard procedures. In order to be sensitive to the anisotropic nature of missing wedge artefacts, we investigate isotropic substructures of metal foam as well as circular disc models. Comparison is drawn to filtered backprojection and algebraic techniques. Reference is made to reconstructions of complete data sets. For the purpose of assessing the reconstruction Quality, Fourier transforms are employed to visualize the missing wedge directly. Deficient reconstructions of disc models are evaluated by a length-weighted boundary orientations. The DIRECTT results are assessd at different signal-to-noise ratios by means of local and integral evaluation Parameters. KW - Tomography KW - Algorithm KW - Reconstruction KW - Computed tomography KW - Electron tomography KW - Image morphology KW - Iterative reconstruction KW - Missing wedge PY - 2016 DO - https://doi.org/10.1111/jmi.12313 SN - 1365-2818 VL - 261 IS - 1 SP - 36 EP - 45 PB - Wiley CY - Hoboken, New Jersey, USA AN - OPUS4-35801 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lange, Axel A1 - Hentschel, Manfred P. A1 - Kupsch, Andreas A1 - Jaenisch, Gerd-Rüdiger A1 - Kardjilov, N. A1 - Tötzke, C. A1 - Markötter, H. A1 - Hilger, A. A1 - Manke, I. T1 - X-ray compton tomography T2 - ECNDT 2014 Proceedings N2 - The potentials of incoherent X-ray Scattering (Compton) tomography are investigated. Imaging materials of very different density or atomic number at once is a perpetual challenge for X-ray tomography or radiography, in general. In a basic laboratory set-up for simultaneous perpendicular Compton Scattering and direct beam attenuation tomographic scans are conducted by single channel photon counting. This results in asymmetric distortions of the projection profiles of the scattering CT-data set. ln a first approach corrections of Compton scattering data by taking advantage of rotational symmetry yield tomograms without major geometric artefacts. A cylindrical sample composed of PE, PA, PVC, glass and wood demonstrates similar Compton contrast for all the substances, while the conventional absorption tomogram only reveals the two high order materials. Compärison to neutron tomography reveals astonishing similarities except for the glass component (without hydrogen). Therefore, Compton CT bears the potential to replace neutron tomography, which requires much more efforts. T2 - ECNDT 2014 - 11th European Conference on Non-Destructive Testing CY - Prague, Czech Republic DA - 06.10.2014 KW - X-ray compton scattering KW - Computed tomography KW - Neutron tomography PY - 2014 SN - 978-80-214-5018-9 SP - 1 EP - 9 PB - Brno University of Technology CY - Brno AN - OPUS4-31972 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Manke, I. A1 - Kardjilov, N. A1 - Schäfer, R. A1 - Hilger, A. A1 - Strobl, M. A1 - Dawson, M. A1 - Grünzweig, C. A1 - Behr, G. A1 - Hentschel, Manfred P. A1 - David, C. A1 - Kupsch, Andreas A1 - Lange, Axel A1 - Banhart, J. T1 - Three-dimensional imaging of magnetic domains JF - Nature communications N2 - Magnetic domains have been the subject of much scientific investigation since their theoretical existence was first postulated by P.-E. Weiss over a century ago. Up to now, the three-dimensional (3D) domain structure of bulk magnets has never been observed owing to the lack of appropriate experimental methods. Domain analysis in bulk matter thus remains one of the most challenging tasks in research on magnetic materials. All current domain observation methods are limited to studying surface domains or thin magnetic films. As the properties of magnetic materials are strongly affected by their domain structure, the development of a technique capable of investigating the shape, size and distribution of individual domains in three dimensions is of great importance. Here, we show that the novel technique of Talbot-Lau neutron tomography with inverted geometry enables direct imaging of the 3D network of magnetic domains within the bulk of FeSi crystals. KW - Computed tomography KW - Reconstruction algorithm KW - Talbot-Lau neutron tomography KW - Magnetic domains PY - 2010 DO - https://doi.org/10.1038/ncomms1125 SN - 2041-1723 SP - 1 EP - 6 PB - Nature Publishing Group CY - London, UK AN - OPUS4-22609 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -