Yamamoto, Kazami; Kinsho, Michikazu; Hayashi, Naoki; Saha, P. K.; Tamura, Fumihiko; Yamamoto, Masanobu; Tani, Norio; Takayanagi, Tomohiro; Kamiya, Junichiro; Shobuda, Yoshihiro; et al.
Journal of Nuclear Science and Technology, 32 Pages, 2022/02
In the Japan Proton Accelerator Research Complex, the purpose of the 3 GeV rapid cycling synchrotron (RCS) is to accelerate a 1 MW, high-intensity proton beam. To achieve beam operation at a repetition rate of 25 Hz at high intensities, the RCS was elaborately designed. After starting the RCS operation, we carefully verified the validity of its design and made certain improvements to establish a reliable operation at higher power as possible. Consequently, we demonstrated beam operation at a high power, namely, 1 MW. We then summarized the design, actual performance, and improvements of the RCS to achieve a 1 MW beam.
Harada, Hiroyuki; Saha, P. K.; Tamura, Fumihiko; Meigo, Shinichiro; Hotchi, Hideaki; Hayashi, Naoki; Kinsho, Michikazu; Hasegawa, Kazuo
Progress of Theoretical and Experimental Physics (Internet), 2017(9), p.093G01_1 - 093G01_16, 2017/09
The 3 GeV rapid cycling synchrotron (RCS) of the J-PARC is a high intensity proton accelerator of 1 MW. The accelerated proton beams in the RCS are extracted by eight pulsed kicker magnets and are delivered to a materials and life science experimental facility and main ring synchrotron. However, the fields of the magnets experience ringing that displaces the position of the extracted beam. This is a major issue from the viewpoint of target integrity and large beam loss. The ringing was directly measured as the displacement of the extracted beams by using a shorter pulsed beam and scanning the entire trigger timing of the kickers. We managed to cancel out the ringing by optimizing trigger timing and achieved the beam extraction with high accuracy. We developed automatic correction system of the timing and now have a higher stability. In this paper, we report our procedure and experimental results for ringing compensation.
Sawabe, Yuki*; Ishiyama, Tatsuya; Takahashi, Daisuke; Kato, Yuko; Suzuki, Takahiro*; Hirano, Koichiro; Takei, Hayanori; Meigo, Shinichiro; Kikuzawa, Nobuhiro; Hayashi, Naoki
Proceedings of 13th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.647 - 651, 2016/11
In the J-PARC, a 3 MeV linac has been developed for the tests of beam scraper irradiation and charge exchange by high-power laser. To accomplish tests efficiently and safely, the control system for 3 MeV was designed and developed, and this system consists of four subsystems, personal protection system, machine protection system, timing system, and remote control system using the EPICS. In this paper, the details of control system for a 3 MeV linac are presented.
Furuta, Takuya; Maeyama, Takuya*; Ishikawa, Kenichi*; Fukunishi, Nobuhisa*; Fukasaku, Kazuaki*; Takagi, Shu*; Noda, Shigeho*; Himeno, Ryutaro*; Hayashi, Shinichiro*
Physics in Medicine & Biology, 60(16), p.6531 - 6546, 2015/08
Low reproducibility of dose distribution in inhomogeneous regions such as soft matter near bones is known with the simple dose analysis currently adopted in treatment planning of particle cancer therapy. Therefore a treatment planning system based on Monte Carlo simulation having better accuracy is highly desired. In order to assess the simulation accuracy of a Monte Carlo simulation code in situations closely related to medical application, we performed a comparison of dose distribution in a biological sample obtained by experiment and that by simulation. In particular, we irradiate a carbon beam on a biological sample composed of fresh chicken meat and bones, with a PAGAT gel dosimeter placed behind it, and compare the complex dose distribution in the gel dosimeter created by the beam passing through the inhomogeneous sample. Monte Carlo simulation using PHITS code was conducted by reconstructing the biological sample from its computed tomography images. The simulation accurately reproduced the experimental distal edge structure of the dose distribution with an accuracy under about 2 mm.
Yamagata, Ichiro; Hayashi, Takehiro; Mashiko, Shinichi*; Sasaki, Shinji; Inoue, Masaki; Yamashita, Shinichiro; Maeda, Koji
JAEA-Testing 2013-004, 23 Pages, 2013/11
In the accident of the Fukushima Daiichi Nuclear Power Plant of Tokyo Electric Power Co. accompanying the Great East Japan Earthquake, fuel assemblies kept in the spent fuel pool of reactor units 1-4, were exposed to the inconceivable environment such as falling and mixing of rubble, especially seawater were injected into unit 2-4. In order to evaluate the integrity of the fuel assemblies in spent fuel pools, and in the long-term storage after transported to the common storage pool, the immersion tests were performed using zircaloy-2 fuel cladding tubes irradiated in the advanced thermal reactor Fugen. The immersion liquid was prepared with doubling dilution of artificial seawater, which temperature was 80 C and immersion time was about 336 hours, as assuming the situation of the pool. The results indicated zircaloy-2 cladding tubes had no significant corrosion and no influence on mechanical property by immersion tests with artificial seawater conditions of this work.
Yoshimoto, Masahiro; Yamamoto, Kazami; Saha, P. K.; Meigo, Shinichiro; Hotchi, Hideaki; Hayashi, Naoki; Okabe, Kota; Kinsho, Michikazu
Proceedings of 3rd International Particle Accelerator Conference (IPAC '12) (Internet), p.2122 - 2124, 2012/05
Transverse beam halo is one of the most important beam parameters due to limit the performance of the high intensity beam accelerator. Therefore the transverse beam halo measurement is required to increase the beam power of the J-PARC 3-GeV RCS. In order to measure the transverse beam halo during the beam operation, halo monitors which are horizontal and vertical scanning aluminum plates type has been installed in the extraction beam line. But the residual secondary electrons hindered the beam halo diagnostic. We report how to take measures against the intrinsic issues of this monitor.
Nagaoka, Shinichi; Ishida, Michihiko; Kanamori, Sadamu; Hayashi, Shinichiro
Proceedings of International Conference on Toward and Over the Fukushima Daiichi Accident (GLOBAL 2011) (CD-ROM), 5 Pages, 2011/12
The feasibility of applying PSA to nuclear fuel cycle facilities such as reprocessing plants has been also studied. We conducted a simplified risk assessment of each of the selected individual accident events and compared the assessment results for four accident categories (fire, explosion, criticality, and other accident events in which large amounts of radioactive materials are released).
Samoto, Hirotaka; Kimura, Norimichi; Otani, Takehisa; Sugai, Eiji; Hayashi, Shinichiro
Proceedings of International Conference on Advanced Nuclear Fuel Cycle; Sustainable Options & Industrial Perspectives (Global 2009) (CD-ROM), p.458 - 463, 2009/09
JAEA has been developing technology to immobilize radioactive krypton gas to metal alloy by ion-implantation method as a stable storage technique of krypton gas recovered from a reprocessing plant. The characteristics of implantation of krypton gas and of krypton implanted alloy were investigated by the cold test performed so far. In this paper, we report the results of the hot immobilization test performed at the Krypton Recovery development Facility (hereafter called KRF) which is attached to the Tokai Reprocessing Plant (hereafter called TRP). In this test, we immobilized the radioactive krypton gas recovered from TRP by cryogenic distillation process of KRF and investigated the gas retention characteristics of the implanted alloy.
Takamura, Shuichi*; Kado, Shinichiro*; Fujii, Takashi*; Fujiyama, Hiroshi*; Takabe, Hideaki*; Adachi, Kazuo*; Morimiya, Osamu*; Fujimori, Naoji*; Watanabe, Takayuki*; Hayashi, Yasuaki*; et al.
Kara Zukai, Purazuma Enerugi No Subete, P. 164, 2007/03
no abstracts in English
Shirai, Nobutoshi; ; ; Shirozu, Hidetomo; Sudo, Toshiyuki; Hayashi, Shinichiro;
JNC TN8410 2000-006, 116 Pages, 2000/04
Criticality limits for equipments in Tokai Reprocessing Plant which handle fissile material solution and are under shape and dimension control were reevaluated based on the guideline No.10 "Criticality safety of single unit" in the regulatory guide for reprocessing plant safety. This report presents criticality safety evaluation of each equipment as single unit. Criticality safety of multiple units in a cell or a room was also evaluated. The evaluated equipments were ones in dissolution, separation, purification, denitration, Pu product storage, and Pu conversion processes. As a result, it was reconfirmed that the equipments were safe enough from a view point of criticality safety of single unit and multiple units.
Hayashi, Shinichiro; ; *; *; *
Computer Physics Communications, 125, p.60 - 74, 2000/00
; ; ; Hayashi, Shinichiro; ;
PNC TN8410 96-055, 147 Pages, 1998/02
; ; ; Hayashi, Shinichiro; ; ;
PNC TN8410 97-329, 355 Pages, 1997/03
Hayashi, Shinichiro; ; ;
Proceedings of International Conference on Future Nuclear Systems (GLOBAL'97), p.620 - 625, 1997/00
*; *; *; Hayashi, Shinichiro*; *; *
PNC TN8440 89-005, 97 Pages, 1989/02
Suzuki, Kazuyuki; Kikuchi, Hideki; Hata, Katsuro; Tanaka, Ken; Miyamoto, Masanori; Nakamura, Yoshinobu; Hayashi, Shinichiro
no journal, ,
no abstracts in English
Hata, Katsuro; Suzuki, Kazuyuki; Kikuchi, Hideki; Kogawa, Takayuki; Nakamura, Yoshinobu; Hayashi, Shinichiro
no journal, ,
no abstracts in English
Suzuki, Kazuyuki; Nakamura, Yoshinobu; Hikita, Keiichi; Kogawa, Takayuki; Hayashi, Shinichiro
no journal, ,
The reprocessing plant dissolves Spent Fuels and it is a process to attract U and Pu after the removal of the Fission Products. Because dissolver is a tank with boiling nitric acid, there is it in the severe corrosion environment. Corrosion environment of the heat transfer surface is the severest. Therefore, the dissolver is made in High Chrome Nickel Steel in consideration of corrosion resistance. This paper reports a supersonic wave measurement method and corrosion rate of the dissolver.
Suzuki, Kazuyuki; Nakamura, Yoshinobu; Miyoshi, Ryuta; Sugai, Eiji; Hayashi, Shinichiro; Uchida, Toshitsugu*
no journal, ,
The pulse filter used by the dissolution and clarification process of the Tokai Reprocessing Plant uses the sintering metal powder filter. As for the sintering metal powder filter, being jammed is easy to occur by sludge. The basic examination of the sintering laminating wire mesh filter for the sintering metal powder filter was carried out.
Samoto, Hirotaka; Kimura, Norimichi; Otani, Takehisa; Sugai, Eiji; Takahashi, Makoto; Hayashi, Shinichiro; Akutsu, Kazuyuki*
no journal, ,
Krypton is immobilized to metal alloy by ion-implantation and sputtering process. The retention characteristic of immobilized radioactive Kr with different storage temperature of the metal alloy is reported.