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Yoshikawa, Tomoki*; Antonov, V. N.*; Kono, Takashi*; Kakoki, Masaaki*; Sumida, Kazuki; Miyamoto, Koji*; Takeda, Yukiharu; Saito, Yuji; Goto, Kazuki*; Sakuraba, Yuya*; et al.
Physical Review B, 102(6), p.064428_1 - 064428_7, 2020/08
Times Cited Count:1 Percentile:13.29(Materials Science, Multidisciplinary)Kono, Takashi*; Kakoki, Masaaki*; Yoshikawa, Tomoki*; Wang, X.*; Sumida, Kazuki*; Miyamoto, Koji*; Muro, Takayuki*; Takeda, Yukiharu; Saito, Yuji; Goto, Kazuki*; et al.
Physical Review B, 100(16), p.165120_1 - 165120_6, 2019/10
Times Cited Count:4 Percentile:22.33(Materials Science, Multidisciplinary)Okabe, Kota; Yamamoto, Kazami; Kamiya, Junichiro; Takayanagi, Tomohiro; Yamamoto, Masanobu; Yoshimoto, Masahiro; Takeda, Osamu*; Horino, Koki*; Ueno, Tomoaki*; Yanagibashi, Toru*; et al.
Proceedings of 14th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.853 - 857, 2017/12
The most important issue is to reduce the uncontrolled beam loss in the high intensity hadron accelerator such as J-PARC proton accelerators. The J-PARC 3 GeV Synchrotron (RCS) has a collimator system which narrows a high intensity beam in the RCS. After startup of RCS in 2007, the collimator system of the RCS worked well. However, in April 2016, vacuum leakage at the collimator system occurred during the maintenance operation. To investigate a cause of the failure, we took apart iron shields of the collimator reducing exposed dose of operators. As a result of inspection, we succeeded to identify the cause of the vacuum leakage failure. In this presentation, we report the failure investigation of the beam collimator system in the RCS.
Nakashima, Yosuke*; Takeda, Hisahito*; Ichimura, Kazuya*; Hosoi, Katsuhiro*; Oki, Kensuke*; Sakamoto, Mizuki*; Hirata, Mafumi*; Ichimura, Makoto*; Ikezoe, Ryuya*; Imai, Tsuyoshi*; et al.
Journal of Nuclear Materials, 463, p.537 - 540, 2015/08
Times Cited Count:18 Percentile:82.74(Materials Science, Multidisciplinary)Nakashima, Yosuke*; Sakamoto, Mizuki*; Yoshikawa, Masayuki*; Oki, Kensuke*; Takeda, Hisahito*; Ichimura, Kazuya*; Hosoi, Katsuhiro*; Hirata, Mafumi*; Ichimura, Makoto*; Ikezoe, Ryuya*; et al.
Proceedings of 25th IAEA Fusion Energy Conference (FEC 2014) (CD-ROM), 8 Pages, 2014/10
Cheng, S.; Tagami, Hirotaka; Yamano, Hidemasa; Suzuki, Toru; Tobita, Yoshiharu; Nakamura, Yuya*; Takeda, Shohei*; Nishi, Shimpei*; Zhang, B.*; Matsumoto, Tatsuya*; et al.
Mechanical Engineering Journal (Internet), 1(4), p.TEP0022_1 - TEP0022_16, 2014/08
Cheng, S.; Yamano, Hidemasa; Suzuki, Toru; Tobita, Yoshiharu; Nakamura, Yuya*; Takeda, Shohei*; Nishi, Shimpei*; Zhang, B.*; Matsumoto, Tatsuya*; Morita, Koji*
Proceedings of 21st International Conference on Nuclear Engineering (ICONE-21) (DVD-ROM), 8 Pages, 2013/07
Yamamoto, Masahiro*; Honda, Yosuke*; Miyajima, Tsukasa*; Uchiyama, Takashi*; Kobayashi, Masanori*; Muto, Toshiya*; Matsuba, Shunya*; Sakanaka, Shogo*; Sato, Kotaro*; Saito, Yoshio*; et al.
Proceedings of 6th Annual Meeting of Particle Accelerator Society of Japan (CD-ROM), p.860 - 862, 2009/08
A newly 500 kV electron gun (2nd - 500 kV gun) for an ERL light source is designed at KEK. A new concept and state of-the-art technologies of vacuum system, ceramic insulators, high voltage power supply, photocathode and preparation system will be employed. The details are described in this report.
Kikuchi, Takayuki; Oku, Takayuki; Shinohara, Takenao; Suzuki, Junichi; Ishii, Yuya; Takeda, Masayasu; Kakurai, Kazuhisa; Sasaki, Yuji*; Kishimoto, Mikio*; Yokoyama, Makoto*; et al.
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no abstracts in English
Ishii, Yuya; Oitani, Seiki; Takeda, Masayasu; Kakurai, Kazuhisa; Kikuchi, Takayuki; Oku, Takayuki; Shinohara, Takenao; Suzuki, Junichi; Sasaki, Yuji*; Kishimoto, Mikio*; et al.
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no abstracts in English
Oitani, Seiki; Ishii, Yuya; Takeda, Masayasu; Kakurai, Kazuhisa; Kikuchi, Takayuki; Oku, Takayuki; Shinohara, Takenao; Suzuki, Junichi; Yokoyama, Makoto*; Nishihara, Yoshikazu*; et al.
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no abstracts in English
Kakurai, Kazuhisa; Takeda, Masayasu; Ishii, Yuya; Oitani, Seiki; Sasaki, Yuji*; Kishimoto, Mikio*; Yokoyama, Makoto*; Nishihara, Yoshikazu*
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Magnetization distribution maps deduced from the measurement of polarization dependent cross-sections have provided unique information in understanding of the detailed electronic configurations in mixed valence materials and molecular magnets. Because of the limited neutron flux the method has been mostly applied to single crystal studies. In the advent of strong pulsed neutron source with intense high resolution powder diffractomer the magnetization distribution measurements by means of polarized neutron powder diffraction can become common place. The introduction of the high magnetic field may extend the applicability of the method to materials requiring high saturation field. In this lecture the polarized neutron powder diffraction experiment on FeN and -Fe fine particles performed in the frame work of "Ibaraki Prefecture Neutron Utilization Working Subgroup on nano-magnetic materials" will be presented and the possibility of the method will be discussed.
Oku, Takayuki; Kikuchi, Takayuki; Oba, Yojiro; Shinohara, Takenao; Suzuki, Junichi; Ishii, Yuya; Oitani, Seiki; Takeda, Masayasu; Kakurai, Kazuhisa; Yokoyama, Makoto*; et al.
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no abstracts in English
Ishii, Yuya; Takeda, Masayasu; Kakurai, Kazuhisa; Kikuchi, Takayuki; Shinohara, Takenao; Oku, Takayuki; Suzuki, Junichi; Sasaki, Yuji*; Kishimoto, Mikio*; Yokoyama, Makoto*; et al.
no journal, ,
no abstracts in English
Kikuchi, Takayuki; Oku, Takayuki; Shinohara, Takenao; Suzuki, Junichi; Ishii, Yuya; Takeda, Masayasu; Kakurai, Kazuhisa; Sasaki, Yuji*; Kishimoto, Mikio*; Yokoyama, Makoto*; et al.
no journal, ,
no abstracts in English
Kikuchi, Takayuki; Oku, Takayuki; Shinohara, Takenao; Suzuki, Junichi; Ishii, Yuya; Takeda, Masayasu; Kakurai, Kazuhisa; Sasaki, Yuji*; Kishimoto, Mikio*; Yokoyama, Makoto*; et al.
no journal, ,
no abstracts in English
Ishii, Yuya; Takeda, Masayasu; Kakurai, Kazuhisa; Kikuchi, Takayuki; Shinohara, Takenao; Oku, Takayuki; Suzuki, Junichi; Kishimoto, Mikio*; Sasaki, Yuji*; Yokoyama, Makoto*; et al.
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The needle-shaped ferromagnetic metals are often used for the magnetic recording tapes. It is, however necessary to make small and spherical shape to increase the recording capacity and density. Recently, FeN round nanoparticles with diameter of 20 nm were produced by Hitachi Maxell, Ltd.. But it is difficult to obtain exact magnitude by conventional magnetometer due to the laminated layer around the FeN. We performed polarized neutron diffraction measurements to determine the net magnetization. The averaged diameter of samples were used in these experiments are approximately 19, 18, 17 and 15 nm. The triple-axis neutron spectrometer, TAS-1, installed at JRR-3 was used in this experiment.
Oku, Takayuki; Kikuchi, Takayuki; Shinohara, Takenao; Suzuki, Junichi; Ishii, Yuya; Takeda, Masayasu; Kakurai, Kazuhisa; Sasaki, Yuji*; Kishimoto, Mikio*; Yokoyama, Makoto*; et al.
no journal, ,
no abstracts in English
Tamai, Yuta; Ishii, Yuya*; Hagiya, Hiroyuki; Kikuchi, Takayuki*; Yokoyama, Makoto*; Nishihara, Yoshikazu*; Takeda, Masayasu; Kakurai, Kazuhisa; Oku, Takayuki; Shinohara, Takenao; et al.
no journal, ,
Magnetic recording tape is widely used for a massive data storage with high reliability, and further increase of capacity, the recording density, is requested by IT organizations. The needle-shaped ferromagnetic metals has been used for the recording media. However, it is necessary to make the media a small and spherical shape to increase the recording density. We have performed the polarized neutron diffraction measurements of FeN round-shape nanoparticles, and determined the saturation magnetic moments and averaged core size of FeN nanoparticles covered by a laminate layer.
Nakamura, Yuya*; Gondai, Yoji*; Cheng, S.*; Takeda, Shohei*; Zhang, B.*; Matsumoto, Tatsuya*; Morita, Koji*; Yamano, Hidemasa; Tagami, Hirotaka; Suzuki, Toru; et al.
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In order to clarify the characteristics of debris bed behavior in the post accident heat removal phase in the core disruptive accidents of FBR, an experimental study to simulate the coolant boiling in debris bed by gas injection from the bottom of the bed and basic knowledge on the self-leveling characteristic for large vapor velocity was obtained.