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.
Soda, Kazuo*; Harada, Shota*; Hayashi, Toshimitsu*; Kato, Masahiko*; Ishikawa, Fumihiro*; Yamada, Yu*; Fujimori, Shinichi; Saito, Yuji
Materials Transactions, 57(7), p.1040 - 1044, 2016/06
Oshima, Katsumi; Oda, Yasuhisa; Takahashi, Koji; Terakado, Masayuki; Ikeda, Ryosuke; Hayashi, Kazuo*; Moriyama, Shinichi; Kajiwara, Ken; Sakamoto, Keishi
JAEA-Technology 2015-061, 65 Pages, 2016/03
In JAEA, an ITER relevant control system for ITER gyrotron was developed according to Plant Control Design Handbook. This control system was developed based on ITER CODAC Core System and implemented state machine control of gyrotron operation system, sequential timing control of gyrotron oscillation startup, and data acquisition. The operation of ITER 170 GHz gyrotron was demonstrated with ITER relevant power supply configuration. This system is utilized for gyrotron operation test for ITER procurement. This report describes the architecture of gyrotron operation system, its basic and detailed design, and recent operation results.
Ishizawa, Akihiro*; Idomura, Yasuhiro; Imadera, Kenji*; Kasuya, Naohiro*; Kanno, Ryutaro*; Satake, Shinsuke*; Tatsuno, Tomoya*; Nakata, Motoki*; Nunami, Masanori*; Maeyama, Shinya*; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 92(3), p.157 - 210, 2016/03
The high-performance computer system Helios which is located at The Computational Simulation Centre (CSC) in The International Fusion Energy Research Centre (IFERC) started its operation in January 2012 under the Broader Approach (BA) agreement between Japan and the EU. The Helios system has been used for magnetised fusion related simulation studies in the EU and Japan and has kept high average usage rate. As a result, the Helios system has contributed to many research products in a wide range of research areas from core plasma physics to reactor material and reactor engineering. This project review gives a short catalogue of domestic simulation research projects. First, we outline the IFERC-CSC project. After that, shown are objectives of the research projects, numerical schemes used in simulation codes, obtained results and necessary computations in future.
Hayashi, Nobuhiko; Honda, Mitsuru; Shiraishi, Junya; Miyata, Yoshiaki; Wakatsuki, Takuma; Hoshino, Kazuo; Toma, Mitsunori; Suzuki, Takahiro; Urano, Hajime; Shimizu, Katsuhiro; et al.
Europhysics Conference Abstracts (Internet), 39E, p.P5.145_1 - P5.145_4, 2015/06
Hayashi, Hirokazu; Akabori, Mitsuo; Minato, Kazuo
Journal of Radioanalytical and Nuclear Chemistry, 303(2), p.1331 - 1334, 2015/02
Electrochemical behavior of Am in NaCl-2CsCl melt at 823 K was investigated by transient electrochemical techniques such as cyclic voltammetry and differential pulse voltammetry. The results show that Am(III) ion is reduced to Am metal by a two-step mechanism via Am(II) ion. Formal standard potential of Am(III)/Am(II) and that of Am(II)/Am(0) redox couples have been determined to be -2.73 and -2.97 V vs Cl/Cl, respectively.
Oda, Yasuhisa; Oshima, Katsumi; Nakamoto, Takashi*; Hashimoto, Yasunori*; Yamamoto, Tsuyoshi; Hayashi, Kazuo*; Ikeda, Yukiharu; Ikeda, Ryosuke; Kajiwara, Ken; Takahashi, Koji; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 90(7), p.365 - 373, 2014/07
no abstracts in English
Takano, Masahide; Hayashi, Hirokazu; Minato, Kazuo
Journal of Nuclear Materials, 448(1-3), p.66 - 71, 2014/05
A powder sample of curium nitride (CmN) containing 0.35%-PuN and 3.59%-AmN was prepared by carbothermic nitridation of the oxide. The lattice expansion induced by self-irradiation damage at room temperature was measured as a function of time. The saturated a/a value was 0.43%, which is greater than those for transuranium dioxides available in literature. The undamaged lattice parameter at 2971 K was determined to be 0.502610.00006 nm. Temperature dependence of the lattice parameter was measured by a high temperature X-ray diffractometer in the temperature range up to 1375 K. The linear thermal expansion of the lattice from 293 to 1273 K is 0.964% and the corresponding thermal expansion coefficient is 9.84 10 K. Comparing with the other actinide nitrides, it was found that CmN lies between the higher expansion nitrides (PuN and AmN) and the lower expansion nitrides (UN and NpN).
Murakawa, Takeshi*; Hayashi, Hideyuki*; Sunami, Tomoko; Kurihara, Kazuo; Tamada, Taro; Kuroki, Ryota; Suzuki, Mamoru*; Tanizawa, Katsuyuki*; Okajima, Toshihide*
Acta Crystallographica Section D, 69(12), p.2483 - 2494, 2013/12
The crystal structure of a Cu amine oxidase from was determined at 1.08 resolution with the use of low-molecular-weight polyethylene glycol (LMW PEG; average molecular weight 200) as a cryoprotectant. The final crystallographic -factor and value are 13.0% and 15.0%, respectively. Several molecules of LMW PEG were found to occupy cavities in the protein interior including the active site, which resulted in the marked reduction of the overall factor and consequently led to a sub-atomic resolution structure for a relatively large protein with a monomer molecular weight of 70,000. About 40% of all the presumed hydrogen atoms were observed as clear electron densities in the - difference map. Multiple minor conformers were also identified for many residues. Anisotropic displacement fluctuations were evaluated in the active site that contains a post-translationally derived quinone cofactor and a Cu atom. Furthermore, diatomic molecules, most likely molecular oxygen, are bound to the protein, one of which is located in the region that has been previously proposed as an entry route for the substrate dioxygen from the central cavity of the dimer interface to the active site.
Hayashi, Hirokazu; Takano, Masahide; Kurata, Masaki; Minato, Kazuo
Journal of Nuclear Materials, 440(1-3), p.477 - 479, 2013/09
Neptunium trichloride of high purity was synthesized by the solid-state reaction of neptunium nitride, which was prepared from the oxide by the carbothermic reduction method, and cadmium chloride in a similar manner as reported for synthesis of AmCl. Lattice parameters of hexagonal NpCl were determined from the X-ray diffraction pattern to be a = 0.7421 0.0006 nm and c = 0.4268 0.0003 nm, which fairly agree with the reported values (a = 0.742 0.001 nm and c = 0.4281 0.0005 nm). Melting temperature of NpCl was measured with about 1 mg of the sample which was hermetically encapsulated in a gold crucible using a differential thermal analyzer with heating and cooling rate of 10 K/min in an argon gas flow (50 mL/min). The melting temperature of NpCl was determined to 1070 3 K, which is close to the recommended value 107530 K, which was derived from the mean value of the melting temperature for UCl(1115K) and that for PuCl (1041 K).
Jeong, J. H.*; Bae, Y. S.*; Joung, M.*; Kim, H. J.*; Park, S. I.*; Han, W. S.*; Kim, J. S.*; Yang, H. L.*; Kwak, J. G.*; Sakamoto, Keishi; et al.
Fusion Engineering and Design, 88(5), p.380 - 387, 2013/06
Hayashi, Hirokazu; Hagiya, Hiromichi; Kim, S.-Y.*; Morita, Yasuji; Akabori, Mitsuo; Minato, Kazuo
Journal of Radioanalytical and Nuclear Chemistry, 296(3), p.1275 - 1286, 2013/06
Cm was separated and recovered as an oxalate from Cm-Pu mixed oxide which had been Cm oxide sample prepared 40 years ago. Plutonium ions were removed from the solution prepared by dissolution of Cm-Pu mixed oxide in nitric acid, by using an anion exchange resin column. Curium oxalate, a precursor compound of curium oxide, was prepared from the purified curium solution and supplied for the syntheses and measurements of the thermochemical properties of curium compounds.
Kajiwara, Ken; Sakamoto, Keishi; Oda, Yasuhisa; Hayashi, Kazuo*; Takahashi, Koji; Kasugai, Atsushi
Nuclear Fusion, 53(4), p.043013_1 - 043013_5, 2013/04
Yagi, Masatoshi; Shimizu, Katsuhiro; Takizuka, Tomonori; Honda, Mitsuru; Hayashi, Nobuhiko; Hoshino, Kazuo; Fukuyama, Atsushi*
Contributions to Plasma Physics, 52(5-6), p.372 - 378, 2012/06
Osaka, Masahiko; Konashi, Kenji*; Hayashi, Hirokazu; Li, D.*; Homma, Yoshiya*; Yamamura, Tomoo*; Sato, Isamu; Miwa, Shuhei; Sekimoto, Shun*; Kubota, Takumi*; et al.
Proceedings of International Conference on Toward and Over the Fukushima Daiichi Accident (GLOBAL 2011) (CD-ROM), 5 Pages, 2011/12
Summer schools for future experts have successfully been completed under Japan Actinide Network (J-ACTINET) for the purpose of development of human resources who are expected to be engaged in every areas of actinide-research/engineering. The first summer school was held in Ibaraki-area in August 2009, followed by the second one in Kansai-area in August 2010. Two summer schools have focused on actual experiences of actinides in actinide-research fields for university students and young researchers/engineers as an introductory course of actinide-researches. Several quasi actinide-handling experiences at the actinide-research fields have attracted attentions of participants at the first school in Ibaraki-area. The actual experiments using actinides-containing solutions have been carried out at the second school in Kansai-area. Future summer schools will be held every year for the sustainable human resource development in various actinide-research fields.
Hayashi, Nobuhiko; Honda, Mitsuru; Hoshino, Kazuo; Hamamatsu, Kiyotaka; Shimizu, Katsuhiro; Takizuka, Tomonori; Ozeki, Takahisa; Fukuyama, Atsushi*
Plasma and Fusion Research (Internet), 6(Sp.1), p.2403065_1 - 2403065_8, 2011/08
Fujii, Toshiyuki*; Okude, Genki*; Uehara, Akihiro*; Sekimoto, Shun*; Hayashi, Hirokazu; Akabori, Mitsuo; Minato, Kazuo; Yamana, Hajimu*
Journal of Radioanalytical and Nuclear Chemistry, 288(1), p.181 - 187, 2011/04
Distribution behavior of Ce(III), Am(III), and Cm(III) between tri-n-butyl phosphate solution and molten calcium nitrate hydrate Ca(NO)HO or molten calcium chloride hydrate CaClHO was studied radiochemically. In Ca(NO)HO systems, maximum separation factors of Ce and Cm to Am were observed to be 12 (Ce/Am) and 1.7 (Cm/Am). The distribution ratios of these elements increased with the decrease of water activity in the hydrates, and the extractabilities at the water deficient region was less sensitive compared to those at the water abundant region. This trend was similar to the coordination circumstance change observed in electronic absorption spectra of Nd(III) in the hydrates.
Shimizu, Katsuhiro; Takizuka, Tomonori; Hoshino, Kazuo; Honda, Mitsuru; Hayashi, Nobuhiko; Takayama, Arimichi*; Fukuyama, Atsushi*; Yagi, Masatoshi*
Proceedings of 23rd IAEA Fusion Energy Conference (FEC 2010) (CD-ROM), 6 Pages, 2011/03
We have developed a self-consistent integrated modelling of core and SOL/divertor transport. Thereby it enables us to investigate operation scenarios to be compatible with high confinement core plasma and detached divertor plasmas. To integrate a 1.5D core code (TOPICS-IB and TASK) and a 2D divertor code (SONIC), we introduce a new Multiple Program Multiple Data parallel computing system. For an integrated code including Monte-Carlo calculations, this system makes it possible to perform efficient simulations. The predictive simulation studies are carried out for JT-60SA with the integrated code (TOPICS-IB/SONIC) and the characteristics of the divertor heat load after the H-mode transition is clarified. We also discuss about the temporal behavior of divertor characteristics after an ELM crash.
Isayama, Akihiko; Sakakibara, Satoru*; Furukawa, Masaru*; Matsunaga, Go; Yamazaki, Kozo*; Watanabe, Kiyomasa*; Idomura, Yasuhiro; Sakamoto, Yoshiteru; Tanaka, Kenji*; Tamura, Naoki*; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 86(6), p.374 - 377, 2010/06
no abstracts in English