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Teshigawara, Makoto; Ikeda, Yujiro*; Yan, M.*; Muramatsu, Kazuo*; Sutani, Koichi*; Fukuzumi, Masafumi*; Noda, Yohei*; Koizumi, Satoshi*; Saruta, Koichi; Otake, Yoshie*
Nanomaterials (Internet), 13(1), p.76_1 - 76_9, 2023/01
Times Cited Count：3 Percentile：44.25(Chemistry, Multidisciplinary)To enhance neutron intensity below cold neutrons, it is proposed that nanosized graphene aggregation could facilitate neutron coherent scattering under particle size conditions similar to nanodiamond. It might also be possible to use it in high neutron radiation conditions due to graphene's strong sp2 bonds. Using the RIKEN accelerator-driven compact neutron source and iMATERIA at J-PARC, we performed neutron measurement experiments, total neutron cross-section, and small-angle neutron scattering on nanosized graphene aggregation. The measured data revealed, for the first time, that nanosized graphene aggregation increased the total cross-sections and small-angle scattering in the cold neutron energy region, most likely due to coherent scattering, resulting in higher neutron intensities, similar to nanodiamond.
Teshigawara, Makoto; Harada, Masahide; Oi, Motoki; Takada, Hiroshi
Journal of Physics; Conference Series, 1021(1), p.012061_1 - 012061_4, 2018/06
Times Cited Count：0 Percentile：0.00(Nuclear Science & Technology)At the spallation neutron source of J-PARC, the structural material of moderators and reflector, such as an aluminum alloy, is going to reach to the design value (20 DPA) around 2020 by an accumulation of irradiation-damage. We started the fabrication of the spare moderators and reflector in 2013 with following design of two improvements. The invar joints, such as invar-A6061 and invar- SS316L joints were newly developed to utilize them in the cryogenic multi-layered pipe with 5th annular geometry, improving the fabrication procedure much simple. The Gold-Indium-Cadmium (Au-In-Cd) as a decoupler material is also developed to reduce residual radioactivity of the used components significantly for the decoupled moderator. In this presentation, we will report these results and progress of fabrication.
Teshigawara, Makoto; Ikeda, Yujiro; Oi, Motoki; Harada, Masahide; Takada, Hiroshi; Kakishiro, Masanori*; Noguchi, Gaku*; Shimada, Tsubasa*; Seita, Kyoichi*; Murashima, Daisuke*; et al.
Nuclear Materials and Energy (Internet), 14, p.14 - 21, 2018/01
Times Cited Count：0 Percentile：0.00(Nuclear Science & Technology)We developed an Au-In-Cd (AuIC) decoupler material to reduce induced radioactivity instead of Ag-In-Cd one, which has a cut off energy of 1eV. In order to implement it into an actual moderator-reflector assembly, a number of critical engineering issues need to be resolved with regard to large-sized bonding between AuIC and A5083 alloys by the hot isostatic pressing process. We investigated this process in terms of the surface conditions, sizes, and heat capacities of large AuIC alloys. We also show a successful implementation of an AuIC decoupler into a reflector assembly, resulting in a remarkable reduction of radioactivity by AuIC compared to AIC without sacrificing neutronic performance.
Teshigawara, Makoto; Aizawa, Hideyuki; Harada, Masahide; Kinoshita, Hidetaka; Meigo, Shinichiro; Maekawa, Fujio; Kaminaga, Masanori; Kato, Takashi; Ikeda, Yujiro
JAERI-Tech 2005-029, 24 Pages, 2005/05
JAERI-Tech-2005-029.pdf:3.38MB
This report introduces the present design status of remote-handling devices for activated and used components such as moderator and reflector in a spallation neutron source of the Material and Life Science Facility (MLF) at J-PARC. The design concept and maintenance scenario are also mentioned. A key maintenance scenario adopts that the used components should be taken out from the MLF to the other storage facility after the volume reduction of them. Almost full remote handling is available to the maintenance work except for the connection/disconnection pipes of the cooling water. Total six remote handling devices are used for moderator-reflector maintenance. They are also available to the proton beam window and muon target maintenance. Maintenance scenario is separated into two works. One is to replace used components to new ones during beam-stop and the other is dispose used components during beam operation. Required period of replacement work is estimated to be 
15 days, on the other hand, the disposal work is 26 days after dry up work (30 days), respectively.
Verzilov, Y. M.; Sato, Satoshi; Nakao, Makoto*; Ochiai, Kentaro; Wada, Masayuki*; Nishitani, Takeo
JAERI-Research 2004-015, 55 Pages, 2004/10
JAERI-Research-2004-015.pdf:3.29MB
no abstracts in English
Harada, Masahide; Teshigawara, Makoto; Kai, Tetsuya; Sakata, Hideaki*; Watanabe, Noboru; Ikeda, Yujiro
Journal of Nuclear Science and Technology, 39(8), p.827 - 837, 2002/08
Times Cited Count：19 Percentile：72.74(Nuclear Science & Technology)For a decoupled hydrogen (super critical) moderator, optimization studies have been performed on a premoderator and reflector material (Pb, Be, Fe and Hg) together with the decoupling energy to realize a higher neutronic performance. The result indicated that the best neutronic performance could be obtained for a decoupled H
moderator in a Pb reflector by optimizing the premoderator and adopting an appropriate decoupling energy, even compared with optimized one in a Be reflector.
Kai, Tetsuya; Teshigawara, Makoto; Watanabe, Noboru; Harada, Masahide; Sakata, Hideaki*; Ikeda, Yujiro
Journal of Nuclear Science and Technology, 39(2), p.120 - 128, 2002/02
Times Cited Count：13 Percentile：60.28(Nuclear Science & Technology)no abstracts in English
Harada, Masahide; Teshigawara, Makoto; Kai, Tetsuya; Sakata, Hideaki*; Watanabe, Noboru; Ikeda, Yujiro
JAERI-Research 2001-016, 32 Pages, 2001/03
JAERI-Research-2001-016.pdf:1.74MB
An optimization study on the premoderator, the reflector material choice and a length of the liner is carried out for the design of high performance decoupled hydrogen moderator. NMTC/JAM and MCNP-4C are used for the neutronics calculation. The result indicates that, assuming premoderator dimensions and decoupling energy is controlled, the decoupled hydrogen moderator with a premoderator can provide better pulse characteristics than that without the premoderator for a Be reflector. On the selection of the reflector material, it is clearly shown that Pb and Hg reflectors give merits in using the premoderator for higher intensity and reduction of energy deposition in moderator. It is also shown that a H2O premoderator provides a short tail while a D2O premoderator provides the high peak intensity. Minimum liner length is evaluated to be 20 cm from the viewpoint of neutronics.
Harada, Masahide; Teshigawara, Makoto; Kai, Tetsuya; Sakata, Hideaki*; Watanabe, Noboru; Ikeda, Yujiro
JAERI-Research 2000-014, p.40 - 0, 2000/03
JAERI-Research-2000-014.pdf:2.99MB
no abstracts in English
Watanabe, Noboru; Teshigawara, Makoto; Kai, Tetsuya; Harada, Masahide; Sakata, Hideaki*; Ikeda, Yujiro; Kaminaga, Masanori; Hino, Ryutaro; Oyama, Yukio
Proceedings of 8th International Conference on Nuclear Engineering (ICONE-8) (CD-ROM), p.12 - 0, 2000/00
no abstracts in English
Teshigawara, Makoto*; Watanabe, Noboru*; Takada, Hiroshi; Kai, Tetsuya; Nakashima, Hiroshi; ; Oyama, Yukio; Ikeda, Yujiro; Kosako, Kazuaki*
JAERI-Research 99-020, 33 Pages, 1999/03
JAERI-Research-99-020.pdf:1.83MB
no abstracts in English
Watanabe, Noboru*; Teshigawara, Makoto*; Aizawa, Kazuya; Suzuki, Junichi; Oyama, Yukio
JAERI-Tech 98-011, 15 Pages, 1998/03
no abstracts in English
Konno, Chikara; Maekawa, Fujio; Oyama, Yukio; Ikeda, Yujiro; Kosako, Kazuaki*; Maekawa, Hiroshi
JAERI-Research 94-043, 96 Pages, 1994/12
JAERI-Research-94-043.pdf:3.5MB
no abstracts in English
Konno, Chikara; Maekawa, Fujio; ; Kosako, Kazuaki*; Ikeda, Yujiro; Oyama, Yukio; Maekawa, Hiroshi
JAERI-Tech 94-019, 43 Pages, 1994/10
no abstracts in English
Oi, Motoki; Teshigawara, Makoto; Harada, Masahide; Takada, Hiroshi
no journal, ,
In the spallation neutron source of the Japan Proton Accelerator Complex (J-PARC), generated neutrons are moderate in liquid hydrogen moderators and supplied to neutron instruments. The design life of the reflector and the moderator is 30,000 MWh (6 years at 1 MW), and we are preparing spare reflector and moderators. In the first ones, Ag-In-Cd alloy decoupler is used, but in order to reduce the residual radioactivity, Au-In-Cd alloy decoupler was developed and adapted to the spare reflector and moderators. It performed R&D about HIP bonding with aluminum alloy, manufacturing and processing method of the Au-In-Cd alloy. In HIP bonding, the optimal conditions were determined by the bonding test using temperature, time, surface condition, etc. as parameters, and these were applied to the spare reflector and moderators. The spare reflector was delivered at the end of FY2015, and now we are preparing decoupled moderators and poisoned moderators with Au-In-Cd alloys.
