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Description
X-ray absorption radiography with a microfocus x-ray source plays an important role in a variety of fields, including industrial application, materials science, and biology, because it enables nondestructive observation of the inside of materials in high spatial resolution. Recently x-ray phase-contrast imaging (XPCI) and small-angle scattering (SAS) imaging have been demonstrated using several techniques to enhance the contrast of light element materials. Among them, the method utilizing a single-amplitude grating is very attractive, because we can freely set optical parameters such as source-grating and grating-detector distances independent of x-ray energy.
In this paper, we demonstrate two improvements of this method utilizing the advantages of a silicon-on-insulator (SOI) pixel detector, SOPHIAS[1]. The detector enables to estimate the energy and incident position of individual x-ray photons. One is single-exposure energy-resolved XPCI, and the other is the improvement in spatial resolution of SAS imaging. In the XPCI, absorption and phase-contrast images of polymethyl methacrylate (PMMA) and Si spheres were obtained for 8- and 15-keV x-rays from single-exposure data, which is very useful in material characterization. Analyzing electric charge generated by x-ray photon irradiation near pixel boundary improved spatial resolution of SAS images in addition to the enhancement of signal-to-noise ratio of XPCI.
[1] T. Hatsui et.al., Proceedings of International Image Sensor Workshop, Article 3.05 (2013).
