Katsuya Hirota
Nagoya University
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Publication
Featured researches published by Katsuya Hirota.
Physical Chemistry Chemical Physics | 2005
Katsuya Hirota; Takenao Shinohara; Kazuaki Ikeda; Kenji Mishima; Tomohiro Adachi; Takahiro Morishima; Setsuo Satoh; T Oku; Satoru Yamada; Hajime Sasao; Jun-ichi Suzuki; Hirohiko M. Shimizu
A neutron scintillation detector based on a position-sensitive photomultiplier has been developed for neutron spin echo and small angle neutron scattering measurements. This photomultiplier has good spatial resolution, less than 1 mm2. The detection efficiency of gamma ray background is very low for using a thin ZnS/6LiF scintillator. The effective area of this detector is around 60 cm2.
Journal of Applied Crystallography | 2007
Takayuki Oku; Hiroki Iwase; Takenao Shinohara; Satoru Yamada; Katsuya Hirota; Satoshi Koizumi; Jun-ichi Suzuki; Takeji Hashimoto; Hirohiko M. Shimizu
We have constructed a focusing-geometry small-angle neutron scattering (FSANS) instrument, SANS-J-II, with two kinds of neutron focusing device: a series of compound refractive lenses made of MgF2 and a magnetic neutron lens based on an extended Halbach-type sextupole magnet. In this study, we investigated the performance of the FSANS instrument with the magnetic neutron lens. The intensity distribution of a direct neutron beam focused on the detector plane by the magnetic neutron lens had a ratio of the peak height to the background level of \sim\!6\times 10^4 for a polarized neutron beam with a polarization degree of \sim \!0.99. It is found that a minimum value of the measurable q range [where q is the modulus of the scattering vector and is defined as q = (4\pi/\lambda)\sin(\theta/2), where \theta is the scattering angle and \lambda is the neutron wavelength], q_{\rm min}, of 6.5 \times 10^{-4} A−1 can be achieved by the FSANS instrument with the magnetic neutron lens using neutrons with \lambda = 6.6 A and \Delta \lambda/\lambda = 0.13 for the full width at half maximum.
IEEE Transactions on Applied Superconductivity | 2010
Yoshihisa Iwashita; Masahiro Ichikawa; Masako Yamada; Takanori Sugimoto; H. Tongu; Hiroshi Fujisawa; M. Masuzawa; T. Tauchi; Takayuki Oku; Katsuya Hirota; Hirohiko M. Shimizu; Caitu Shi; Y Zhu
Permanent magnets are superior to electromagnets in generating strong multipole magnetic fields. Their fields are sometimes stronger than those that can be generated by superconducting magnets with the same bore radius, when the number of poles are higher. Three fabricated multipoles including a quadrupole magnet for the ILC (International Linear Collider) final focus doublet, a quadrupole magnets as a spin filter for cold neutrons, and a sextupole magnet for neutron beam focusing are described.
Proceedings of The 3rd International Symposium on “Quest for the Origin of Particles and the Universe" — PoS(KMI2017) | 2017
N. Naganawa; Shogo Awano; Masahiro Hino; Masanori Hirose; Katsuya Hirota; Hiroki Kawahara; Masaaki Kitaguchi; Kenji Mishima; Tomofumi Nagae; Hirohiko M. Shimizu; Satomi Tada; Seiji Tasaki; Atsuhiro Umemoto
We have been developing neutron detectors with spatial resolution of submicron to several tens of nanometers using fine-grained nuclear emulsion with nuclides with large neutron absorption cross sections such as 6Li and 10B. Those detectors were demonstrated their ability to detect cold and ultra-cold neutrons.
Proceedings of The 3rd International Symposium on “Quest for the Origin of Particles and the Universe" — PoS(KMI2017) | 2017
Noriko Oi; Hirohiko M. Shimizu; Katsuya Hirota; Masaaki Kitaguchi; Christopher C. Haddock; W. M. Snow; T. Yoshioka; Satoru Matsumoto; Kenji Mishima; T. Ino; T. Shima
We are searching for an unknown force that could couple to mass using neutron scattering from a noble gas. The neutron is a chargeless massive particle with a long lifetime, which consequently is suitable for the precision measurement of a small interaction with a range of the order of 1 nm by measurements of the momentum transfer distribution. We measured neutron scattering at the low-divergence beam branch on the BL05 NOP beamline in the Materials and Life Science Experimental Facility (MLF) at the Japan Proton Accelerator Research Complex (J-PARC). We measured 105 scattering events and report our most recent analysis.
Journal of Physics: Conference Series | 2012
Yoshie Otake; Margie P. Olbinado; Yoshichika Seki; Katsuya Hirota; Yutaka Yamagata; Jungmyoung Ju; Tomohiro Adach; I Shinya Morita; Yoshihisa Iwashita; Masahiro Hino; Masahiro Ichikawa; Masaaki Kitaguchi; Toshio Takahashi; Hideki Yoshizawa; Seung Wook Lee; Wataru Yashiro; Atsushi Momose
The neutron interference imaging experiment with two absorption gratings has been done. We develop new way to fabricate absorption gratings for neutron with the pitch of 150 μ m, 180 μ m, and 200 μ m. Compact imaging detector system is developed, whose weight is 2kg. Small break in an acrylic plate, the welded place of Nb plate were observed, it reveals that the neutron interference imaging method can become new method of a nondestructive inspection for reinforced plastics and composite material such as CFRP and so on.
SYNCHROTRON RADIATION INSTRUMENTATION: Eighth International Conference on Synchrotron Radiation Instrumentation | 2004
Masayo Suzuki; H. Toyokawa; Katsuya Hirota
We have developed a new X‐ray beam intensity monitor based upon rare gas scintillation in order to solve (i) the non‐ion‐saturation problem occurring ionization chambers when irradiated with high flux X‐ray beams and (ii) the slow time response of ionization chambers. When argon gas is used, it has been confirmed that the scintillation output was proportional to an X‐ray intensity up to 1015 xph/sec, and responded to an X‐ray beam with a time resolution better than 50 nsec. The rare gas scintillation X‐ray beam monitor developed is compatible to ionization chamber in terms of its readout electronics and the physical size, so that it can easily substitute existing ionization chambers when needed.
Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment | 2003
Masayo Suzuki; Hidenori Toyokawa; Katsuya Hirota; M. Itou; M. Mizumaki; Y. Sakurai; N. Hiraoka; Nobuhiko Sakai
A 128-channel microstrip Germanium detector system has been developed to efficiently detect Compton-scattered X-rays and to effectively reject the background X-rays associated in the Compton spectrometer of the high-energy inelastic scattering beamline at the SPring-8 facility. In order to handle the large number of the readout channels, four 32-parallel-input front-end hybrid boards have been adopted as charge-sensitive pre-amplifiers and discriminators, which are currently controlled by a Windows-based PC data-acquisition system.
Physical Review D | 2018
Christopher C. Haddock; Noriko Oi; Katsuya Hirota; Takashi Ino; Masaaki Kitaguchi; Satoru Matsumoto; Kenji Mishima; T. Shima; Hirohiko M. Shimizu; W. Michael Snow; T. Yoshioka
We describe an experimental search for deviations from the inverse-square law of gravity at the nanometer length scale using neutron scattering from noble gases on a pulsed slow neutron beam line. By measuring the neutron momentum transfer (q) dependence of the differential cross section for xenon and helium and comparing to their well-known analytical forms, we place an upper bound on the strength of a new interaction as a function of interaction length λ which improves upon previous results in the region λ<0.1 nm, and remains competitive in the larger-λ region. A pseudoexperimental simulation is developed for this experiment and its role in the data analysis is described. We conclude with plans for improving sensitivity in the larger-λ region.
Journal of Nuclear Science and Technology | 2018
Tetsuya Kai; Takashi Kamiyama; Fujio Hiraga; Motoki Ooi; Katsuya Hirota; Yoshiaki Kiyanagi
ABSTRACT Extensive simulation calculations were performed in the design studies of the coupled hydrogen moderator for the pulsed spallation neutron source of the Japan Proton Accelerator Research Facility (J-PARC). It was indicated that a para-hydrogen moderator had an intensity-enhanced region at the fringe part, and that pulse shapes emitted from a cylindrical para-hydrogen moderator gave higher pulse-peak intensities with narrower pulse widths than those from a rectangular one without penalizing the time-integrated intensities. To validate the peculiar distribution and advantages in pulse shapes experimentally, some measurements were performed at the neutron source of the Hokkaido University electron linear accelerator facility. It was observed that the neutron intensity was enhanced at edges of the para-hydrogen moderators, whereas it decreased at the same part of the ortho-rich-hydrogen moderator, where the dimension of those moderators was 50 mm in thickness and 120 mm in width and height. The spatial distribution and pulse shapes were also measured for a cylindrical coupled para-hydrogen moderator that has the same dimensions as for the coupled moderator employed for J-PARC. The measured results from the cylindrical moderator were consistent with the results obtained in the design studies for the moderator for J-PARC.