This study explores recent developments in quantitative phase-contrast microtomography using Talbot Array Illuminators (TAI) combined with Unified Modulated Pattern Analysis (UMPA). We first compare the performance of the TAI-based method for phase-retrieval with propagation-based imaging (PBI) for analyzing a Mg-10Gd bone implant sample that violates the single-material assumption. Our results demonstrate that the TAI method yields a significantly higher contrast-to-noise ratio (CNR) compared to PBI (101.68 vs. 54.37, an 87% improvement) while maintaining comparable edge sharpness. The TAI method also visualizes a substructure of the degradation layer, which appears comparatively blurred in the PBI images. Additionally, we introduce a hanging-rotation-axis approach for imaging paraffin-embedded samples in an ethanol bath, aiming to reduce edge enhancement artifacts caused by large electron density differences. Preliminary results indicate that the TAI-based images of a paraffin-embedded lymph node show improved uniformity in background intensity, though some additional low-frequency noise is observed. All experiments were conducted at the High Energy Materials Beamline (HEMS), PETRA III, DESY, operated by Hereon. Our findings highlight the potential of TAI-based phase-contrast imaging for complex, multi-material samples and suggest avenues for further optimization of the technique.
A high-energy white synchrotron x-ray beam enables penetration of relatively thick and highly absorbing samples. At the P61A White Beam Engineering Materials Science Beamline, operated by Helmholtz-Zentrum Hereon at the PETRA III ring of the Deutsches Elektronen-Synchrotron (DESY), a tailored x-ray radiography system has been developed to perform in-situ x-ray imaging experiments at high temporal resolution, taking advantage of the unprecedented x-ray beam flux delivered by ten successive damping wigglers. The imaging system is equipped with an ultrahigh-speed camera (Phantom v2640) enabling acquisition rates up to 25 kHz at maximal resolution and binned mode. The camera is coupled with optical magnification (5x, 10x) and focusing lenses to enable imaging with a pixel size of 1,35 micrometre. The scintillator screens are housed in a special nitrogen gas cooling environment to withstand the heat load induced by the beam, allowing spatial resolution to be optimized down to few micrometres. We present the current state of the system development, implementation and first results of in situ investigations, especially of the electron beam powder bed fusion (PBF-EB) process, where the details of the mechanism of crack and pore formation during processing of different powder materials, e.g. steels and Ni-based alloys, is not yet known.
The Helmholtz-Zentrum Hereon, Germany, is operating the user experiments for microtomography at the beamlines P05 and P07 using synchrotron radiation produced in the storage ring PETRA III at DESY, Hamburg, Germany. Attenuation-contrast and phase-contrast techniques were established to provide an imaging tool for applications in biology, medical science and materials science. Within the recent years we built an imaging pipeline to optimize the deliverd radiation dose onto the sample with respect to the applied imaging technique. This became possible by the modernisation of the experiment control and the integration of different imaging detectors. In combination with an new concept for a high-speed X-ray shutter the applied radiation dose can be adjusted from high, for optimization of the statistic within the tomogram, to low, for avoiding any radiation based artefact. Within this talk the recent hardware and software developments integrated to the microtomography imaging system at the beamlinew P05/PETRA III and P07/PETRA III will be presented. Furthermore, the optimization of dose will be demonstrated on selected samples.
The Helmholtz-Zentrum Geesthacht, Germany, is operating the user experiments for microtomography at the beamlines P05 and P07 using synchrotron radiation produced in the storage ring PETRA III at DESY, Hamburg, Germany. Attenuation-contrast and phase-contrast techniques were established to provide an imaging tool for applications in biology, medical science and materials science. In the recent years we rebuilt the integration of imaging detectors. This allows the user to choose from a set of cameras based on different CMOS and CCD sensors. Here we will present the features of the different camera system together with the advantage for different applications. Furthermore, we rebuilt the data preprocessing before reconstruction to provide different scanning techniques to investigate samples larger than the field of view of the X-ray beam. Multi-scale tomography is realized by using different setups or to integrate a low-resolution together with a high-resolution region-of-interest invest
X-ray computed tomography (CT) has become an established technique in the biomedical imaging or materials science
research. Its ability to non-destructively provide high-resolution images of samples makes it attractive for diverse fields
of research especially the paleontology. Exceptionally, the Precambrian is a geological time of rocks deposition
containing several fossilized early animals, which still need to be investigated in order to predict the origin and evolution
of early life. Corumbella werneri is one of those fossils skeletonized in Corumbá (Brazil). Here, we present a study on
selected specimens of Corumbella werneri using absorption-based contrast imaging at diverse tomographic setups. We
investigated the potential of conventional laboratory-based device and synchrotron radiation sources to visualize internal
structures of the fossils. The obtained results are discussed as well as the encountered limitations of those setups.
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