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Tajima, Yoshihiro; Kuwabara, Jun; Oyokawa, Atsushi; Kabuto, Shoji; Araya, Naoyuki; Kikuchi, Kaoru; Miyamoto, Shingo; Nemoto, Hideyuki; Oe, Osamu
JAEA-Review 2016-003, 56 Pages, 2016/05
Nuclear Facilities Management Section implements the operation, maintenance and decommissioning of the first nuclear ship "MUTSU" and the operation and maintenance of the liquid waste facility and the solid waste facility where a small amount of nuclear fuel is used. This is the report on the operations of the Nuclear Facilities Management Section for FY 2012 and FY 2013.
Yamada, Junya; Seya, Natsumi; Haba, Risa; Muto, Yasunobu; Numari, Hideyuki*; Sato, Naomitsu*; Nemoto, Koji*; Takasaki, Hiroichi*; Shimizu, Takehiko; Takasaki, Koji
JAEA-Data/Code 2013-006, 100 Pages, 2013/06
This report presents the results of emergency radiation monitoring, including ambient -ray dose rate, atmospheric radioactivity, meteorological observation and estimation of internal exposure resulting from the accident at the Fukushima Daiichi Nuclear Power Plant triggered by the earthquake off the pacific coast of Tohoku on 11th March 2011, conducted by Oarai Research and Development Center (ORDC), Japan Atomic Energy Agency (JAEA) from March to May, 2011. ORDC is located in the central part of Ibaraki prefecture and approximately 130 km southwest of the Fukushima Daiichi Nuclear Power Plant. From around 15th to 21st March, 2011, the ambient -ray dose rate increased and many radioactive nuclides were detected in the atmosphere.
Kando, Masaki; Fukuda, Yuji; Kotaki, Hideyuki; Koga, J. K.; Bulanov, S. V.; Tajima, Toshiki; Chao, A. W.*; Pitthan, R.*; Schuler, K.-P.*; Zhidkov, A. G.*; et al.
Journal of Experimental and Theoretical Physics, 105(5), p.916 - 926, 2007/11
Times Cited Count:15 Percentile:62.99(Physics, Multidisciplinary)We suggest a novel method for injection of electrons into the acceleration phase of particle accelerators, producing low emittance beams appropriate even for the demanding high energy Linear Collider specifications. We discuss the injection mechanism into the acceleration phase of the wake field in a plasma behind a high intensity laser pulse, which takes advantage of the laser polarization and focusing. As shown in three-dimensional particle-in-cell simulations of the interaction of an elongated in transverse direction laser pulse with an underdense plasma, the electrons, injected via the transverse wake wave breaking and accelerated by the wake wave, perform betatron oscillations with different amplitudes and frequencies along the two transverse coordinates. The polarization and focusing geometry lead to a way to produce relativistic electron bunches with asymmetric emittance (flat beam). An approach for generating flat laser accelerated ion beams is briefly discussed.
Kotaki, Hideyuki; Oishi, Yuji*; Nayuki, Takuya*; Fujii, Takashi*; Nemoto, Koshichi*; Nakajima, Kazuhisa
Review of Scientific Instruments, 78(3), p.036102_1 - 036102_3, 2007/03
Times Cited Count:0 Percentile:0.01(Instruments & Instrumentation)no abstracts in English
Yamazaki, Atsushi; Kotaki, Hideyuki; Daito, Izuru; Kando, Masaki; Bulanov, S. V.; Esirkepov, T. Z.; Kondo, Shuji; Kanazawa, Shuhei; Homma, Takayuki*; Nakajima, Kazuhisa; et al.
Physics of Plasmas, 12(9), p.093101_1 - 093101_5, 2005/09
Times Cited Count:70 Percentile:88.85(Physics, Fluids & Plasmas)no abstracts in English
Nemoto, Hideyuki; Wakai, Eiichi; Kinoshita, Hidetaka; Masuda, Shiho; Harada, Masahide; Takada, Hiroshi; Ishikawa, Koji*; Imanari, Kei*; Ito, Takeshi*
no journal, ,
no abstracts in English
Masuda, Shiho; Kai, Tetsuya; Harada, Masahide; Kinoshita, Hidetaka; Wakai, Eiichi; Nemoto, Hideyuki; Ikeda, Yujiro; Haga, Katsuhiro
no journal, ,
In the Materials and Life science experimental Facility at J-PARC, pulsed neutrons are provided by a mercury target via spallation reactions. During the target vessel replacement, gaseous spallation products are released from the mercury circulation system to outside. The release of radioactive gases needs to be reduced to a negligibly small level by a purging process in advance of replacement. The radioactivity of noble gases decreased by the purging process while that of tritium was almost unchanged. It is considered that most of tritium produced in mercury is accumulated in the vessel made of stainless-steel and is gradually desorbed during the purging and the vessel replacement. However, there have been no effective data associated with tritium behavior in an environment of mercury spallation target. Then, authors decided to develop an experimental system to understand these phenomena quantitatively and to discuss procedures to minimize tritium release during the vessel replacement. As a first step, we start experiments using deuterium before using tritium. Accumulation and release behaviors of deuterium to stainless-steel are examined under vacuum, controlled humidity and mercury coexistence conditions. Results are expected to be used to establish safer the target vessel replacement.