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Yasushi Kagoshima

  (篭島 靖)

Profile Information

Affiliation
Professor, Graduate School of Science, University of Hyogo
Degree
Doctor of Engineering(Mar, 1990, University of Tsukuba)
Master of Engineering(Mar, 1985, University of Tsukuba)

Researcher number
10224370
ORCID ID
 https://orcid.org/0000-0003-4622-9102
J-GLOBAL ID
200901027407263123
researchmap Member ID
1000144092

External link

Education

 2

Papers

 118
  • Yuki Takayama, Yasushi Kagoshima
    Japanese Journal of Applied Physics, 63(3) 038001-038001, Mar 1, 2024  Peer-reviewed
    Abstract In coherent X-ray diffraction imaging, speckles on a coherent diffraction pattern must be sampled at intervals sufficiently finer than the Nyquist interval, which imposes an upper limit on the sample size. To overcome the size limitation, a sub-pixel shift method for upsampling coherent diffraction patterns was proposed. This paper reports on the evaluation of the noise tolerance of the upsampling algorithm by a simulation. The quality of the images reconstructed from the upsampled diffraction pattern and pattern recorded by a detector with an equivalent pixel size was comparable when the optimum number of upsampling iterations is adopted.
  • Yasushi Kagoshima, Tatsuki Akada, Takumi Ikeda
    SPring-8/SACLA Research Report, 10(6) 524-529, Dec, 2022  Peer-reviewedLead authorCorresponding author
  • Yuki Takayama, Keizo Fukuda, Motoki Kawashima, Yuki Aoi, Daiki Shigematsu, Tatsuki Akada, Takumi Ikeda, Yasushi Kagoshima
    Communications Physics, 4(1), Dec, 2021  Peer-reviewed
    <title>Abstract</title>The quest for understanding the structural mechanisms of material properties and biological cell functions has led to the active development of coherent diffraction imaging (CDI) and its variants in the hard X-ray regime. Herein, we propose multiple-shot CDI, a full-field CDI technique dedicated to the visualisation of local nanostructural dynamics in extended objects at a spatio-temporal resolution beyond that of current instrumentation limitations. Multiple-shot CDI reconstructs a “movie” of local dynamics from time-evolving diffraction patterns, which is compatible with a robust scanning variant, ptychography. We developed projection illumination optics to produce a probe with a well-defined illumination area and a phase retrieval algorithm, establishing a spatio-temporal smoothness constraint for the reliable reconstruction of dynamic images. The numerical simulations and proof-of-concept experiment using synchrotron hard X-rays demonstrated the capability of visualising a dynamic nanostructured object at a frame rate of 10 Hz or higher.
  • Yasushi Kagoshima, Yuki Takayama
    Japanese Journal of Applied Physics, 60(11) 118001-118001, Nov 1, 2021  Peer-reviewedLead authorCorresponding author
    Abstract The optical transfer function (OTF) of an inverse-phase composite zone plate under incoherent illumination was numerically evaluated by convoluting the point spread function (PSF) and transmission distribution of a model sample with gradually changing spatial frequency. The PSF used in the simulation was obtained from our previous study on deep-focusing X-ray microscopes. As expected, the contrast in the sample image was lesser than that produced by a conventional zone plate. Phase-reversed contrast—spurious resolution—appeared at a high spatial frequency. Although the calculated OTF is slightly aberrated, its deep-focusing capability is advantageous for X-ray microimaging of thick samples.
  • Atsushi Mineshige, Atsushi Saito, Mio Kobayashi, Hikaru Hayakawa, Mizuki Momai, Tetsuo Yazawa, Hideki Yoshioka, Mitsumasa Sakao, Ryohei Mori, Yuki Takayama, Yasushi Kagoshima, Junji Matsui
    Journal of Power Sources, 475, Nov 1, 2020  Peer-reviewed
    © 2020 Elsevier B.V. An oxide ion (O2−) conducting membrane cell, based on lanthanum silicate oxyapatite (La9.33+xSi6O26+1.5x, LSO), exhibiting low ohmic and polarization resistances in the intermediate-temperature region (~873 K) was developed. As a solid electrolyte, highly conductive Mg-doped LSO, La9·8(Si5·7Mg0.3)O26.4 (MDLS), modified with another kind of non-conductive lanthanum silicate, La2SiO5 was employed. Two kinds of silicate layers were successively spin-coated on a Ni-MDLS porous anode support, followed by thermal treatment aimed at improving ionic conductivity as well as densification of MDLS through solid state reactive diffusion. In addition, the Gd-doped CeO2, (Ce0.9Gd0.1)O1.95 (GDC) electrolyte layer, which plays an important role to prevent a reaction between the electrolyte and cathode materials, was spin-coated on the modified MDLS electrolyte. Finally, the cathode layer of porous (La,Sr)(Co,Fe)O3-δ was screen printed on the electrolyte layers. The resulting cell obtained from this study showed good fuel cell performance with a maximum power density of 94 mW cm−2 at 873 K, when operated with argon-diluted hydrogen and pure oxygen gasses.

Misc.

 86
  • Yasushi Kagoshima, Yuki Takayama
    PROCEEDINGS OF THE 15TH INTERNATIONAL CONFERENCE ON X-RAY MICROSCOPY – XRM2022, 030002-1-030002-4, Sep, 2023  Lead authorCorresponding author
  • Yasushi Kagoshima, Kentaro Uesugi, Takashi Kameshima, Yukio Takahashi, Yasuo Takeichi, Akihisa Takeuchi, Tetsuo Harada, Hironori Matsumoto, Hidekazu Mimura, Wataru Yashiro
    51(4) 167-168, Apr, 2022  InvitedLead authorCorresponding author
  • Yasushi Kagoshima
    50(9) 393-396, Sep, 2021  InvitedLead authorLast authorCorresponding author
  • H Takano, K Sumida, H Hirotomo, T Koyama, S Ichimaru, T Ohchi, H Takenaka, Y Kagoshima
    Journal of Physics: Conference Series, 849 012052-012052, Jun, 2017  Last author
    We have improved the performance of a previously reported multilayer zone plate by reducing its outermost zone width, using the same multilayer materials (MoSi2 and Si) and fabrication technique. The focusing performance was evaluated at the BL24XU of SPring-8 using 20-keV X-rays. The line spread function (LSF) in the focal plane was measured using a dark-field knife-edge scan method, and the point spread function was obtained from the LSF through a tomographic reconstruction principle. The spatial resolution was estimated to be 30 nm, which is in relatively good agreement with the calculated diffraction-limited value of 25 nm, while the measured diffraction efficiency of the + 1st order was 24%.
  • Toshiki Hirotomo, Hidekau Takano, Kazuhiro Sumida, Takahisa Koyama, Shigeki Konishi, Satoshi Ichimaru, Tadayuki Ohchi, Hisataka Takenaka, Yoshiyuki Tsusaka, Yasushi Kagoshima
    XRM 2014: PROCEEDINGS OF THE 12TH INTERNATIONAL CONFERENCE ON X-RAY MICROSCOPY, 1696, 2016  Last author
    Multilayer zone plate (MZP) technology for hard X-ray focusing was upgraded and its focusing performance was evaluated using 20-keV X-rays at the synchrotron beamline (BL24XU) of SPring-8. The MZP consists of MoSi2 and Si layers alternately deposited on a glass fiber by magnetron sputtering so that all zone boundaries satisfy the Fresnel zone configuration. The focused beam was evaluated using knife-edge scanning in which the measured intensity distribution is identical to the line spread function (LSF) in the focal plane. The focused beamsize of about 30 nm was estimated by oscillation peaks observed in the measured LSF according to Rayleigh's criterion.

Books and Other Publications

 1

Presentations

 4

Professional Memberships

 3

Research Projects

 11

Social Activities

 6