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Yokoyama, Akihito; Kada, Wataru*; Sato, Takahiro; Koka, Masashi; Shimada, Keisuke*; Yokota, Yuya*; Miura, Kenta*; Hanaizumi, Osamu*
Nuclear Instruments and Methods in Physics Research B, 371, p.340 - 343, 2016/03
Times Cited Count：6 Percentile：49.29(Instruments & Instrumentation)no abstracts in English
Saito, Toru; Okubo, Toshikazu*; Izumi, Keisuke*; Okawa, Yoshinao*; Kobayashi, Norihiro*; Yamazaki, Toru; Kawano, Katsumi; Isono, Takaaki
Teion Kogaku, 50(8), p.400 - 408, 2015/08
Aramid fiber-reinforced plastic (AFRP) has been developed as a structural material that has the advantages of light weight and high strength. In this study, tensile tests were carried out to measure the tensile properties of AFRP rod on the market for reinforcement of concrete at room temperature, 77 K and 4.2 K. Especially at cryogenic temperatures, it is difficult to perform a tensile test of the bar because the specimen slips through the jig grip. To prevent the rod from slipping, tensile tests were carried out with some filling conditions. The applicable and appropriate tensile test conditions were established by modifying the jig grip, treating the surface of the rod and using cryogenic epoxy infill to grip the rod. They were more than 1100 MPa. Additionally, the AFRP rod included a temperature dependence in which the Young's modulus increased as the test temperature decreased. It was confirmed that the Young's modulus increased because aramid fiber was more dominant than epoxy.
Chiba, Go; Okumura, Keisuke; Oizumi, Akito*; Saito, Masaki*
Journal of Nuclear Science and Technology, 47(7), p.652 - 660, 2010/07
Times Cited Count：7 Percentile：45.04(Nuclear Science & Technology)In order to specify important nuclear data for accurate prediction of fission product concentrations(FPC), we extensively evaluate sensitivities of FPC to nuclear data with the depletion perturbation theory. The target fission products are twelve important ones for the burnup credit. The present study successfully specifies the important nuclear data both in a UO
cell and in a MOX cell. While the obtained sensitivities are mostly similar to each other between the UO and MOX cells, large differences are observed in some cases, such as the Gd-155 concentration. It is clearly shown that such differences between the UO and MOX cells come from differences in cumulative fission yields between U-235 and Pu-239 and differences in neutron flux energy spectra.
Osawa, Takahito; Hatsukawa, Yuichi; Nagao, Keisuke*; Koizumi, Mitsuo; Oshima, Masumi; Toh, Yosuke; Kimura, Atsushi; Furutaka, Kazuyoshi
Geochemical Journal, 43(6), p.415 - 422, 2009/00
Times Cited Count：4 Percentile：16.49(Geochemistry & Geophysics)The Cretaceous-Tertiary (K-T) boundary about 65 million years ago records a mass extinction event caused by a bolide impact. K-T boundary clay collected from Stevns Klint, Denmark was investigated in this work. Iridium concentrations of eight clays across the K-T boundary were determined using a multiple 
-ray analysis system after neutron activation. Anomalously high Ir concentrations were detected in five marl samples, with the highest concentration being 29.9 ppb. Four samples were analyzed for all noble gases. No extraterrestrial Ar, Kr, and Xe were discovered in any of the samples, although most of the 
He which was detected was extraterrestrial. Solar-like Ne was observed only in the sample SK4, which had an Ir concentration of 14.3 ppb, indicating the presence of micrometeorites.
Hori, Toshihiko*; Ito, Takashi; Chishiro, Etsuji; Izumi, Keisuke*; Yamazaki, Masayoshi*; Watanabe, Kazuhiko*; Takasaki, Eiichi*; Hasegawa, Kazuo; Yoshikawa, Hiroshi
Proceedings of 27th Linear Accelerator Meeting in Japan, p.255 - 257, 2002/08
no abstracts in English
Okawa, Yoshinao; Kashimura, Shinji*; Murano, Yoshihiro*; Ito, Michio*; Okada, Kenichi*; Izumi, Keisuke*; Tsuchida, Takashi*
Dai-19-Kai Denki Setsubi Gakkai Zenkoku Taikai Koen Rombunshu, p.415 - 416, 2001/00
no abstracts in English
Okawa, Yoshinao; Murano, Yoshihiro*; Okada, Kenichi*; Kawakami, Kunio*; Izumi, Keisuke*; *; Sasaki, Takashi*; *
Heisei 12-Nendo Denki Setsubi Gakkai Zenkoku Taikai Koen Rombunshu, p.315 - 316, 2000/00
no abstracts in English
CIshimori, Kenichiro; Oki, Keiichi; Kameo, Yutaka; Takaizumi, Hirohide; Nakashima, Mikio; Oki, Yoshiyuki*; Isogai, Keisuke*
no journal, ,
no abstracts in English
Imaizumi, Mitsuru*; Saito, Masashi*; Sato, Shinichiro; Yasuda, Keisuke*
no journal, ,
no abstracts in English
Imaizumi, Tomomi; Kadotani, Hiroyuki*; Okumura, Keisuke; Katakura, Junichi; Nagao, Yoshiharu
no journal, ,
no abstracts in English
Izumi, Keisuke*; Iguchi, Masayuki*; Kawasaki, Masaji*; Okawa, Yoshinao*; Oka, Kiyoshi; Yamagata, Ryohei; Koyanaka, Akihiro*
no journal, ,
At penetration parts in radiation controlled areas, such as walls and floors where cables go through, the high-airtight performance is required in order to control the negative pressure of air-conditioning. Moreover, since the cables get deteriorated by radiation, the easy replacement works are indispensable. However, the materials in general use have neither resistance, nor any sheltering performance against radiation. In this research, we have developed radiation-proof materials, to meet both an airtight and a sheltering performance.
substrates implanted with Si and C ionsInada, Kazuki*; Kawashima, Akihiro*; Kano, Keisuke*; Noguchi, Katsuya*; Miura, Kenta*; Hanaizumi, Osamu*; Yamamoto, Shunya; Kawaguchi, Kazuhiro*; Yoshikawa, Masahito
no journal, ,
It is reported that Si and C ions implanted SiO substrates emit blue light. In this paper, we are studying photoluminescence (PL) properties of SiO substrates implanted with Si and C ions on various conditions. Si and C ions were implanted into an SiO substrate by using a 400-kV ion implanter at JAEA/Takasaki. The Si-ion implantation energy was 150 keV, and the implantation dose was 
5.0
10
ions/cm
. The C-ion implantation energy was 75 keV, and the implantation dose was 3.010 ions/cm. The samples were subsequently annealed at 700
C for 25 min in air, after 1000C for 25 min in air. The results of PL measurements show that the PL peak wavelength became shorter by increasing the ratio of C ions to Si ions. Consequently, it was confirmed that the emission wavelength can be controlled by hanging the ratio of C and Si.
Matoba, Shiro; Narumi, Kazumasa; Saito, Yuichi; Chiba, Atsuya; Yamada, Keisuke; Kamiya, Tomihiro; Koizumi, Tetsuo*; Takahashi, Karin*; Ishikawa, Manabu*; Moriya, Sosuke*; et al.
no journal, ,
no abstracts in English
Ito, Chikara; Naito, Hiroyuki; Ito, Hideaki; Imaizumi, Kazuyuki; Nagai, Akinori; Ito, Keisuke; Nishimura, Akihiko; Oba, Hironori; Wakaida, Ikuo; Sugiyama, Akira; et al.
no journal, ,
no abstracts in English
Naito, Hiroyuki; Ito, Chikara; Ito, Hideaki; Imaizumi, Kazuyuki; Ito, Keisuke
no journal, ,
no abstracts in English
Kamikawa, Masaaki*; Izumi, Keisuke*; Kawasaki, Masaji*; Oka, Kiyoshi; Yamagata, Ryohei
no journal, ,
no abstracts in English
Saura, Keisuke*; Obana, Tetsuhiro*; Takata, Suguru*; Natsume, Kyohei*; Hamaguchi, Shinji*; Chikaraishi, Hirotaka*; Takahata, Kazuya*; Imagawa, Shinsaku*; Kajitani, Hideki; Hemmi, Tsutomu; et al.
no journal, ,
The full size joint test of ITER TF coil was performed using NIFS test facility. Because of transport current of 68kA, which is high current never experienced before, the reduction of cupper busbar heating was needed. Therefore, high temperature superconducting (HTS) busbar (Bi2212 fabricated by Sumitomo Electric Co.,Ltd) was installed in parallel with cupper busbar. In the test, current of HIS busbar was measured using rogowski coil and it was observed that the current of 20 kA could be distributed to HTS busbar. Therefore, the cupper busbar heating could be reducted to about 60% compared with the case of no HTS busbar.
Naito, Hiroyuki; Ito, Chikara; Ito, Keisuke; Imaizumi, Kazuyuki; Ito, Hideaki; Nagai, Akinori
no journal, ,
no abstracts in English
Kamikawa, Masaaki*; Izumi, Keisuke*; Takemoto, Jumpei*; Kawasaki, Masaji*; Oka, Kiyoshi; Yamagata, Ryohei
no journal, ,
no abstracts in English
Izumi, Keisuke*; Iguchi, Masayuki*; Iida, Shinji*; Kawasaki, Masaji*; Okawa, Yoshinao*; Oka, Kiyoshi; Yamagata, Ryohei
no journal, ,
no abstracts in English
