Dr. Hiroyuki Sekiguchi Profile

Dr. Hiroyuki Sekiguchi

Lecturer at Kyoto Univ Hospital

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Author

Publications (7)

Proceedings Article | 19 February 2018 Paper

Body surface detection method for photoacoustic image data using cloth-simulation technique

H. Sekiguchi, A. Yoshikawa, Y. Matsumoto, Y. Asao, T. Yagi, K. Togashi, M. Toi

Proceedings Volume 10494, 1049459 (2018) https://doi.org/10.1117/12.2287352

KEYWORDS: Blood vessels, Image processing, Visualization, Photoacoustic tomography, Tissues, Computer simulations, Computer graphics, Medical image processing, Medical image visualization

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Proceedings Article | 28 June 2006 Paper

An application of active optics to x-ray imaging: X-mas (x-ray milli arc-second) project

Masahiro Tsujimoto, Shunji Kitamoto, Yohsuke Ohkubo, Jun'ichi Sato, Takeshi Watanabe, Keisuke Sudoh, Akiko Sekiguchi, Kazuharu Suga, Hiroyuki Sekiguchi

Proceedings Volume 6272, 62724T (2006) https://doi.org/10.1117/12.670937

KEYWORDS: X-rays, X-ray optics, X-ray imaging, X-ray detectors, Mirrors, Adaptive optics, Wavefronts, Charge-coupled devices, Deformable mirrors, X-ray telescopes

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Proceedings Article | 1 September 2005 Paper

Adaptive x-ray optics with a deformable mirror

Shunji Kitamoto, Norimasa Yamamoto, Takayoshi Kohmura, Kazuharu Suga, Hiroyuki Sekiguchi, Jun'ichi Sato, Keisuke Sudo, Takeshi Watanabe, Youhei Ohkubo, Akiko Sekiguchi, Masahiro Tsujimoto

Proceedings Volume 5900, 590019 (2005) https://doi.org/10.1117/12.620162

KEYWORDS: X-rays, X-ray optics, Adaptive optics, Mirrors, Reflectivity, X-ray telescopes, Telescopes, Deformable mirrors, X-ray sources, Charge-coupled devices

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We are developing a soft x-ray telescope with an adaptive optics system for future astronomical observation with very fine angular resolution of an order of milli-arc-second. From a technical point of view, we are trying to develop a normal incident telescope with multi layers. Thus the wave length is limited to be around 13.5 nm with a band pass of roughly 1nm. Since the x-ray telescope must be installed on a satellite, a stable conditions of temperature, gravity etc, can not be expected. Therefore, we investigate to use an adaptive optics system using an optical light source attached in the telescope. In this paper, we report our present status of the development. The primary mirror is an off-axis paraboloid with 80 mm effective diameter and 2 m focal length. This mirror has been coated with Mo/Si multi-layers. The reflectivity of the 13.5 nm x rays is ranging from 35% to 55%. We use a deformable mirror for the secondary mirror, which has also been coated with Mo/Si multi-layers. This mirror consists of 31 element-bimorph-piezo electrodes. The surface roughness of the mirror is ~6 nm rms. The reflectivity of the 13.5 nm x rays is roughly 65%. The adaptive optics system using an optical laser and a wave front sensor has been performed. We are using a shack-hartmann sensor (HASO 32) with a micro-lens array and a CCD. A pin hole with one micron diameter is used for the optical light source. The precision of the measurement of the wave front shape is a few nm. X-ray exposure test is now conducting, although the optical adaptive optics system is not yet installed. The x-ray detector is a back illumination CCD. The quantum efficiency for 13.5 nm x ray is ~50%. The pixel size is 24 micron square. X-ray source is an electron impact source with an Al/Si alloy target. We confirmed that the x-ray intensity around 13.55 nm is bright enough for our experiment. The imaging performance is now trying to improve and the adaptive optics system will be installed in this year.

Proceedings Article | 11 October 2004 Paper

Evaluation of an ultra-high-precision x-ray optics

Shunji Kitamoto, Norimasa Yamamoto, Takayoshi Kohmura, Kazuharu Suga, Hiroyuki Sekiguchi, Youhei Ohkawa, Junichi Kanai, Shigeto Chiba, Junichi Sato, Keisuke Sudo, Takeshi Watanabe

Proceedings Volume 5488, (2004) https://doi.org/10.1117/12.550364

KEYWORDS: Wavefronts, Mirrors, Deformable mirrors, X-rays, Space telescopes, X-ray telescopes, Telescopes, X-ray optics, Charge-coupled devices, Wavefront sensors

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Proceedings Article | 29 January 2004 Paper

Soft x-ray transmission of optical blocking filters for the x-ray CCD camera onboard Astro-E2

Shunji Kitamoto, Takayoshi Kohmura, Norimasa Yamamoto, Haruko Takano, Harue Saito, Kazuharu Suga, Hiroyuki Sekiguchi, S. Chiba, I. Okamoto, Kiyoshi Hayashida, Haruyoshi Katayama, Toyonaka Enoguchi, Yuusuke Nakashima, T. Shiroshouji, Yuzuru Tawara, Akihiro Furuzawa, Takeshi Tanaka

Proceedings Volume 5168, (2004) https://doi.org/10.1117/12.505589

KEYWORDS: X-rays, Aluminum, X-ray optics, Transmittance, Optical filters, Absorption, CCD cameras, Data modeling, X-ray astronomy, Oxidation

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Proceedings Article | 24 December 2003 Paper

Development of ultrahigh-precision x-ray optics

Shunji Kitamoto, Haruko Takano, Harue Saitoh, Norimasa Yamamoto, Takayoshi Kohmura, Kazuharu Suga, Hiroyuki Sekiguchi, Yohei Ohkawa, Jun'ichi Kanai, Shigeto Chiba

Proceedings Volume 5169, (2003) https://doi.org/10.1117/12.505571

KEYWORDS: Wavefronts, Deformable mirrors, X-rays, Mirrors, X-ray optics, Charge-coupled devices, X-ray telescopes, Telescopes, Optical filters, Wavefront sensors

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Proceedings Article | 16 June 2003 Paper

Development of an ultra high-precision x-ray telescope with an adaptive optics system

Shunji Kitamoto, Haruko Takano, Harue Saitoh, Norimasa Yamamoto, Takayoshi Kohmura, Kazuharu Suga, Hiroyuki Sekiguchi

Proceedings Volume 5037, (2003) https://doi.org/10.1117/12.482338

KEYWORDS: X-rays, Mirrors, X-ray optics, X-ray telescopes, Deformable mirrors, Optical filters, Telescopes, Adaptive optics, Wavefront sensors, Diffraction

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Showing 5 of 7 publications

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