Publications by authors named "Kyosuke Ozaki"

SiO2 aggregates in styrene-butadiene rubber (SBR) were observed using ptychographic X-ray computed tomography (PXCT). The rubber composites were illuminated with X-rays focused by total reflection focusing mirrors, and the ptychographic diffraction patterns were collected using a CITIUS detector in the range of -75° to +75° angle of incidence. The projection images of the rubber composites were reconstructed with a two-dimensional resolution of 76 nm, and no significant structural changes were observed during the PXCT measurements.

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We developed a novel quasielastic scattering spectroscopy system that uses a multiline frequency comblike resolution function to overcome the limit on the accessible timescale imposed by the inherent single-energy resolution of conventional spectroscopy systems. The new multiline system possesses multiple resolutions and can efficiently cover a wide time range, from 100 ps to 100 ns, where x-ray-based dynamic measurement techniques are being actively developed. It enables visualization of the relaxation shape and wave-number-dependent dynamic behavior using a two-dimensional detector, as demonstrated for the natural polymer polybutadine without deuteration.

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The CITIUS detector is a next-generation high-speed X-ray imaging detector. It has integrating-type pixels and is designed to show a consistent linear response at a frame rate of 17.4 kHz, which results in a saturation count rate of over 30 Mcps pixel when operating at an acquisition duty cycle close to 100%, and up to 20 times higher with special extended acquisition modes.

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Ptychographic coherent diffraction imaging (PCDI) is a synchrotron X-ray microscopy technique that provides high spatial resolution and a wide field of view. To improve the performance of PCDI, the performance of the synchrotron radiation source and imaging detector should be improved. In this study, ptychographic diffraction pattern measurements using the CITIUS high-speed X-ray image detector and the corresponding image reconstruction are reported.

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With low-emittance synchrotron radiation rings, introducing accurate x-ray beams to a sample is difficult, and ensuring that the direction of the undulator beam is stable is essential. However, measuring the centroid of the undulator photon beam at the beamline front-end (FE) is difficult because the soft x-ray radiation is contaminated by the bending magnets upstream and downstream of the undulator. The x-ray beam position monitors (XBPMs), based on the interaction with the halo of undulator radiation, cannot estimate the centroid of the beam, and they cannot eliminate the effects of the bending magnets.

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We show how to improve microfocus X-ray radiography by using the SOPHIAS silicon-on-insulator pixel detector in conjunction with an amplitude grating. Single-exposure multi-energy absorption and differential phase contrast imaging was performed using the single amplitude grating method. The sensitivity in differential phase contrast imaging in a two-pixel-pitch setup was enhanced by 39% in comparison with the previously reported method [Rev.

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This paper presents development of an X-ray pixel detector with a multi-port charge-coupled device (MPCCD) for X-ray Free-Electron laser experiments. The fabrication process of the CCD was selected based on the X-ray radiation hardness against the estimated annual dose of 1.6 × 10(14) photon/mm(2).

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Purpose: We evaluated a self-color developing sheet-type film for the detection of dead seeds in I-125 permanent implant therapy for prostate cancer.

Materials And Methods: As a preliminary study, we irradiated X-rays to a self-developing reflection-type sheet film and created a relational curve between absorbed dose and film density. I-125 seeds were placed on a film and the approximate absorbed dose of I-125 was calculated from the relational curve of X-rays.

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