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Yamashita, Keishiro*; Komatsu, Kazuki*; Klotz, S.*; Fabelo, O.*; Fern
ndez-D
az, M. T.*; Abe, Jun*; Machida, Shinichi*; Hattori, Takanori; Irifune, Tetsuo*; Shimmei, Toru*; et al.
Proceedings of the National Academy of Sciences of the United States of America, 119(40), p.e2208717119_1 - e2208717119_6, 2022/10
Times Cited Count：2 Percentile：22.35(Multidisciplinary Sciences)Here we present the first elucidation of the disordered structure of ice VII, the dominant high-pressure form of water, at 2.2 GPa and 298 K from both single-crystal and powder neutron diffraction techniques. We reveal the three-dimensional atomic distributions from the maximum entropy method and unexpectedly find a ring-like distribution of hydrogen in contrast to the commonly-accepted discrete sites. In addition, total scattering analysis at 274 K clarified the difference in the intermolecular structure from ice VIII, the ordered counterpart of ice VII, despite an identical molecular geometry. Our complementary structure analyses robustly demonstrate the unique disordered structure of ice VII. Furthermore, these noble findings are related to the proton dynamics which drastically vary with pressure, and will contribute to an understanding of the structural origin of anomalous physical properties of ice VII under pressures.
Yamashita, Keishiro*; Komatsu, Kazuki*; Ohara, Takashi; Munakata, Koji*; Irifune, Tetsuo*; Shimmei, Toru*; Sugiyama, Kazumasa*; Kawamata, Toru*; Kagi, Hiroyuki*
High Pressure Research, 42(1), p.121 - 135, 2022/03
Times Cited Count：3 Percentile：58.88(Physics, Multidisciplinary)Nakamoto, Tatsushi*; Sugano, Michinaka*; Xu, Q.*; Kawamata, Hiroshi*; Enomoto, Shun*; Higashi, Norio*; Idesaki, Akira; Iio, Masami*; Ikemoto, Yukio*; Iwasaki, Ruri*; et al.
IEEE Transactions on Applied Superconductivity, 25(3), p.4000505_1 - 4000505_5, 2015/06
Times Cited Count：0 Percentile：0(Engineering, Electrical & Electronic)Recently, development of superconducting magnet system with high radiation resistance has been demanded for application in accelerator facilities such as CERN LHC. In order to realize superconducting magnet system with high radiation resistance, it is necessary to develop electrical insulator with high radiation resistance because the electrical insulator is made of organic materials whose radiation resistance is inferior to that of inorganic materials. We developed a glass fiber reinforced plastic with bismaleimide-triazine resin. The developed material showed excellent radiation resistance; the material evolved gases of 5
10 
mol/g and maintained flexural strength of 640MPa (90% of initial value).
Sato, Takeshi; Muto, Shigeo; Akiyama, Kiyomitsu; Aoki, Kazufumi; Okamoto, Akiko; Kawakami, Takeshi; Kume, Nobuhide; Nakanishi, Chika; Koie, Masahiro; Kawamata, Hiroyuki; et al.
JAEA-Review 2014-048, 69 Pages, 2015/02
JAEA-Review-2014-048.pdf:13.91MB
JAEA was assigned as a designated public institution under the Disaster Countermeasures Basic Act and under the Armed Attack Situations Response Act. Based on these Acts, the JAEA has the responsibility of providing technical support to the national government and/or local governments in case of disaster responses or response in the event of a military attack, etc. In order to fulfill the tasks, the JAEA has established the Emergency Action Plan and the Civil Protection Action Plan. In case of a nuclear emergency, NEAT dispatches specialists of JAEA, supplies the national government and local governments with emergency equipment and materials, and gives technical advice and information. In normal time, NEAT provides various exercises and training courses concerning nuclear disaster prevention to those personnel taking an active part in emergency response institutions of the national and local governments, police, fire fighters, self-defense forces, etc. in addition to the JAEA itself. The NEAT also researches nuclear disaster preparedness and response, and cooperates with international organizations. In the FY2013, the NEAT accomplished the following tasks: (1) Technical support activities as a designated public institution in cooperation with the national and local governments, etc. (2) Human resource development, exercise and training of nuclear emergency response personnel for the national and local governments, etc. (3) Researches on nuclear disaster preparedness and response, and sending useful information (4) International contributions to Asian countries on nuclear disaster preparedness and response in collaboration with the international organizations
Sato, Takeshi; Muto, Shigeo; Okuno, Hiroshi; Katagiri, Hiromi; Akiyama, Kiyomitsu; Okamoto, Akiko; Koie, Masahiro; Ikeda, Takeshi; Nemotochi, Toshimasa; Saito, Toru; et al.
JAEA-Review 2013-046, 65 Pages, 2014/02
JAEA-Review-2013-046.pdf:11.18MB
When a nuclear emergency occurs in Japan, the Japan Atomic Energy Agency (JAEA) has the responsibility of providing technical support to the National government, local governments, police, fire stations and nuclear operators etc., because the JAEA has been designated as the Designated Public Institution under the Basic Act on Disaster Control Measures and the Act on Response to Armed Attack Situations, etc.. The Nuclear Emergency Assistance and Training Center (NEAT) of JAEA provides a comprehensive range of technical support activities to an Off-Site Center in case of a nuclear emergency. Specifically, NEAT gives technical advice and information, dispatches specialists as required, and supplies the National Government and local governments with emergency equipments and materials. NEAT provides various exercise and training courses concerning nuclear disaster prevention to those personnel taking an active part in emergency response organizations at normal times. The tasks of NEAT, with its past experiences as a designated public institution including the responses to TEPCO's Fukushima Accident, have been shifted to technical supports to the national government for strengthening its abilities to emergency responses; the NEAT therefore focused on maintenance and operation of its functions, and strengthening its response abilities in cooperation with the national government. This annual report summarized these activities of JAEA/NEAT in the fiscal year 2012.
Sakata, Shinya; Yamaguchi, Taiji; Sugimura, Toru; Kominato, Toshiharu; Kawamata, Yoichi; Totsuka, Toshiyuki; Sato, Minoru; Sueoka, Michiharu; Naito, Osamu
Fusion Science and Technology, 60(2), p.496 - 500, 2011/08
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)For a steady state operation of JT-60SA, a plasma feedback control using various diagnostic sensor signals plays an essential role. To realize this, Real Time Diagnostic Signals acquisition System, RTDS, which utilizes PC-based real-time OS "INtime", has been under consideration toward JT-60SA project. Moreover, long-time experiments more than 100 seconds will be planned in JT-60SA project. Therefore, real time monitoring will be required as an essential function that displays acquired diagnostic signals on real time during long-time experiment. This function will be also realized by utilizing RTDS.
Kawamata, Yoichi; Sugimura, Toru; Yamaguchi, Taiji; Sueoka, Michiharu; Sakata, Shinya; Totsuka, Toshiyuki; Sato, Minoru; Kominato, Toshiharu; Naito, Osamu
Fusion Science and Technology, 60(2), p.491 - 495, 2011/08
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)Yagyu, Junichi; Sasajima, Tadayuki; Miyo, Yasuhiko; Sakakibara, Satoru*; Kawamata, Yoichi
JAEA-Technology 2007-015, 27 Pages, 2007/03
JAEA-Technology-2007-015.pdf:2.94MB
The feedback control of the plasma position and shape based on signals of magnetic probes is performed on JT-60. The fabrication cost of these magnetic probes is very high. Therefore, the cost reduction is required for the use in a next device. On the other hand, the magnetic field measurement in three axial directions with the advanced technology (AT) probes is simultaneously made on LHD of NIFS. The AT-probe has been developed at a low fabrication cost and in compact size and light weight. The possibility of application of the AT-probe in a Tokamak device (JT-60U) has been investigated in collaboration between JAEA and NIFS. We designed and fabricated the casing and interface for the AT-probe, and installed it under the first wall of JT-60U. A comparison of output signals between the installed AT-probe and a existing magnetic probe was made. Tests have been carried out to evaluate the vibration resistance and the radioactive resistance through about two thousand shots with high performance plasmas including one hundred disruption shots in JT-60U. As a result, the AT-probe has a good performance and an enough usable prospect in environment of the Tokamak device.
Kawamata, Yoichi; Yonekawa, Izuru; Kurihara, Kenichi; Sakakibara, Satoru*; Nishimura, Kiyohiko*
Annual Report of National Institute for Fusion Science; April 2002 - March 2003, 59 Pages, 2003/00
no abstracts in English
Fukuda, Takeshi; Oikawa, Toshihiro; Takeji, Satoru; Isayama, Akihiko; Kawano, Yasunori; Neyatani, Yuzuru; Nagashima, Akira; Nishitani, Takeo; Konoshima, Shigeru; Tamai, Hiroshi; et al.
Fusion Science and Technology (JT-60 Special Issue), 42(2-3), p.357 - 367, 2002/09
Times Cited Count：7 Percentile：44.35(Nuclear Science & Technology)no abstracts in English
Sueoka, Michiharu; Akasaka, Hiromi; Sugimura, Toru; Kawamata, Yoichi; Kurihara, Kenichi; Naito, Osamu
no journal, ,
no abstracts in English
Kawamata, Yoichi; Naito, Osamu; Kurihara, Kenichi; Totsuka, Toshiyuki; Akasaka, Hiromi; Sueoka, Michiharu; Sugimura, Toru
no journal, ,
no abstracts in English
