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This paper gives a brief overview on3D imaging of magnetic domains with shearing grating neutron tomography. We investigated the three-dimensional distribution of magnetic domain walls in the bulk of a wedge-shaped FeSi single crystal. The width of the magnetic domains wasanalyzed at different locations within the crystal. Magnetic domains close to the tip of the wedge are much smaller than in the bulk. Furthermore, the three-dimensional shape of individual domains wasinvestigated. We discuss prospects and limitations of the applied measurement technique.
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.
The neutron imaging instrument CONRAD was operated as a part of the user program of the research reactor BER‐II at Helmholtz‐Zentrum Berlin (HZB) from 2005 to 2020. The Instrument was designed to use the neutron flux from the cold source of the reactor, transported by a curved neutron guide. The pure cold neutron spectrum provided a great advantage in the use of different neutron optical components such as focusing lenses and guides, solid‐state polarizers, Monochromators and phase gratings. The flexible setup of the instrument allowed for implementation of new methods including wavelength‐selective, dark‐field, phase‐contrast and imaging with polarized neutrons. In summary, these developments helped to attract a large number of scientists and industrial customers, who were introduced to neutron imaging and subsequently contributed to the Expansion of the neutron imaging community.
Understanding the complicated interplay of the continuously evolving electrode materials in their inherent 3D states during the battery operating condition is of great importance for advancing rechargeable battery research.
In this regard, the synchrotron X-ray tomography technique, which enables non-destructive, multi-scale, and 3D imaging of a variety of electrode components before/during/after battery operation, becomes an essential tool to deepen this understanding. The past few years have witnessed an increasingly growing interest in applying this technique in battery research. Hence, it is time to not only summarize the already obtained battery-related Knowledge by using this technique, but also to present a fundamental elucidation of this technique to boost future studies in battery research. To this end, this review firstly introduces the fundamental principles and experimental Setups of the synchrotron X-ray tomography technique. After that, a user guide to ist application in battery research and examples of its applications in Research of various types of batteries are presented. The current review ends with a discussion of the future opportunities of this technique for next-generation rechargeable batteries research. It is expected that this review can enhance the reader’s understanding of the synchrotron X-ray tomography technique and stimulate new ideas and opportunities in battery research.