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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:2 Percentile:66.71(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.
Harada, Masahide; Teshigawara, Makoto; Oi, Motoki; Oikawa, Kenichi; Takada, Hiroshi; Ikeda, Yujiro
Nuclear Instruments and Methods in Physics Research A, 1000, p.165252_1 - 165252_8, 2021/06
Times Cited Count:2 Percentile:32.77(Instruments & Instrumentation)This study explores high-energy neutron components of the extracted neutron beam at J-PARC pulsed neutron source using the foil activation method with threshold reactions. Foils of aluminum, gold, bismuth, niobium, and thulium were used to cover the neutron energy range from 0.3 MeV to 79.4 MeV. The experiment was performed using neutron beams of BL10 (NOBORU). The foils were irradiated by a neutron beam at 13.4 m from the moderator. To characterize high-energy neutron fields for irradiation applications, reaction rates in three different configurations with and without BC slit and Pb filter were examined. To compare the experiments with calculations given for the user, reaction rates for corresponding reactions were calculated by the PHITS code with the JENDL-3.2 and the JENDL dosimetry file. Although there was a systematic tendency in C/E (Calculation/Experiment) ratios for different threshold energies, which C/E ratio decreased as threshold energy increased up to 100 MeV, and all C/E ratios were in the range of 1.00.2. This indicated that high-energy neutron calculations were adequate for the analysis of experimental data for NOBORU users.
Yamaguchi, Mika; Hidaka, Akihide; Ikuta, Yuko; Murakami, Kenta*; Tomita, Akira*; Hirose, Hiroya*; Watanebe, Masanori*; Ueda, Kinichi*; Namaizawa, Ken*; Onose, Takatoshi*; et al.
JAEA-Review 2017-002, 60 Pages, 2017/03
Since 2010, IAEA has held the NEM School to develop future leaders who plan and manage nuclear energy utilization in their county. Since 2012, JAEA together with Japan Nuclear HRD Network, University of Tokyo, Japan Atomic Industrial Forum and JAIF International Cooperation Center have cohosted the school in Japan in cooperation with IAEA. Since then, the school has been held in Japan every year. In 2006, Japanese nuclear technology and experience, such as lessons learned from the Fukushima Daiichi Nuclear Power Plant accident, were provided to offer a unique opportunity for the participants to learn about particular cases in Japan. Through the school, we contributed to the internationalization of Japanese young nuclear professionals, development of nuclear human resource of other countries including nuclear newcomers, and enhanced cooperative relationship with IAEA. Additionally, collaborative relationship within the network was strengthened by organizing the school in Japan.
Kasugai, Yoshimi; Harada, Masahide; Kai, Tetsuya; Oi, Motoki; Meigo, Shinichiro; Maekawa, Fujio
JAEA-Data/Code 2015-033, 28 Pages, 2016/03
The high-energy neutron fluxes and spectra around the mercury spallation neutron source at MLF of J-PARC were measured by the multi-foil activation method. The threshold energies of neutron reactions utilized in this experiment covered from 0.1 to 50 MeV. The foil irradiation was carried out on the first beam-run of MLF from May 30th to 31th, 2008. After the irradiation, the induced radioactivity of each foil was measured using an HPGe detector, and the neutron-induced reaction-rate distribution around the mercury target was determined. Using these data, the high-energy neutron fluxes and spectra were deduced with unfolding method in which the neutron spectra calculated with PHITS code were used as the initial-guess spectra. By comparison between the initial and the unfolded spectra, it was shown that most of the calculation results, which had been the basis of the neutronics design of the MLF target assembly, were consistent with the experimental data within 30%.
Nishiyama, Jun*; Ohgama, Kazuya; Sakamoto, Tatsujiro*; Watanabe, Rin*
Nihon Genshiryoku Gakkai-Shi ATOMO, 57(2), p.123 - 125, 2015/02
no abstracts in English
Yoshida, Hajime; Yokoyama, Kenji; Suzuki, Satoshi; Enoeda, Mikio; Akiba, Masato
Review of Scientific Instruments, 77(4), p.043502_1 - 043502_4, 2006/04
Times Cited Count:0 Percentile:0.01(Instruments & Instrumentation)New beam extraction electrode has been developed for a 100 eV level, high-flux, large irradiation area, and steady-state ion beam source to study about plasma wall interaction in fusion reactors. This electrode has two specific features; one is the structure has sub-millimeter order of spherical multi-aperture triode electrodes and the other is to utilize the plasma sheath for ion acceleration. Obtained ion fluxes ware from 1.51020 H/ms to 5.31020 H/ms with the energy from 28 eV/H to 102 eV/H. These values are comparable to those of conventional high flux ion source in spite of such an extremely low energy.
Hanada, Masaya; Seki, Takayoshi*; Takado, Naoyuki*; Inoue, Takashi; Morishita, Takatoshi; Mizuno, Takatoshi*; Hatayama, Akiyoshi*; Imai, Tsuyoshi*; Kashiwagi, Mieko; Sakamoto, Keishi; et al.
Fusion Engineering and Design, 74(1-4), p.311 - 317, 2005/11
Times Cited Count:7 Percentile:44.75(Nuclear Science & Technology)no abstracts in English
Suzuki, Takayoshi*
JAERI-Review 2005-042, 38 Pages, 2005/09
After the Basic Plan on Energy was determined, a set of policy measures as proposed in order to accelerate a shift to natural gas: development of domestic infrastructure of natural gas utilization, making effort to lower and stabilize import prices of LNG, support for introducing gas cogeneration, etc. Also the Program to Achieve Kyoto-Protocol Target proposes to promote the natural gas shift. In these circumstances, this report summarizes the results of investigation on natural gas resources, LNG import, domestic infrastructure of natural gas utilization, current and future prices of natural gas, the development of natural gas utilization technologies, and new types of fuel for end-use. Natural gas is expected more abundant than petroleum, therefore Japan has increased its import. In addition, its prices might be lower in the future in comparison with petroleum prices. Natural gas will take more important role as a primary energy source in Japan under the support program by the Government.
Minehara, Eisuke
Proceedings of 2nd Annual Meeting of Particle Accelerator Society of Japan and 30th Linear Accelerator Meeting in Japan, p.55 - 56, 2005/07
The next generation high brightness and high current electron source like a photo cathode, a thermionic cathode, a crystal Diamond electron cathode and others would be expected to realize the next generation ERL (energy recovery linac) based light source and SASE X-ray free-electron laser. The JAERI FEL group has recently started to develop a new crystal Diamond electron cathode technology for high current, high brightness, and long life electron source. In the presentation, we plan to explain and to discuss our strategy and a preliminary experimental measurements of the crystal Diamond cathode, and related Diamond cathode evaluation system.
Minehara, Eisuke
Proceedings of 2nd Annual Meeting of Particle Accelerator Society of Japan and 30th Linear Accelerator Meeting in Japan, p.200 - 201, 2005/07
As the fourth generation energy recovering super-conducting linac (ERL) driven light source is planned to develop and to build as the most advanced national light source facility in Japan, this is a conceptual design work and key components developmental programs including a 200MeV prototype construction. Our existing 4K zero-boil off refrigerator cryogenic and a huge 2K liquefier facility will be combined to make a new hybrid one. Because all cryogenic devices in Japan have been seriously and unnecessarily controlled and affected their safety, maintenance, operation and construction over these several tens years, we will therefore have to cut back excess safety regulation in Japanese domestic high pressure vessel code using a structure reform and special economic zone policy.
Saegusa, Jun; Kawasaki, Katsuya; Mihara, Akira; Ito, Mitsuo; Yoshida, Makoto
Applied Radiation and Isotopes, 61(6), p.1383 - 1390, 2004/12
Times Cited Count:29 Percentile:85.14(Chemistry, Inorganic & Nuclear)no abstracts in English
Yoshizawa, Michio; Endo, Akira
JAERI-Conf 2003-002, 166 Pages, 2003/03
The present report is Proceedings of the Third Workshop on Dosimetry for External Radiations, held at the Tokai Research Establishment, Japan Atomic Energy Research Institute (JAERI), in November 28-29, 2002. The proceedings comprises 16 papers and a summary of general discussion. The Third Workshop, subtitled "On an opportunity of the completion of the facility of calibration standards for neutron at JAERI", focused on neutron dosimetry and included presentations on the status of international neutron standards, the development of calibration techniques of neutron dosimeters using accelerator neutron sources, and dosimetry for high-energy neutrons. The workshop identified the directions for the future research and development in this field.
Taniguchi, Masaki; Sato, Kazuyoshi; Ezato, Koichiro; Yokoyama, Kenji; Dairaku, Masayuki; Akiba, Masato
Journal of Nuclear Materials, 313-316(1-3), p.360 - 363, 2003/03
Times Cited Count:10 Percentile:56.31(Materials Science, Multidisciplinary)no abstracts in English
Kume, Tamikazu
Proceedings of 9th International Conference on Radiation Curing (RadTech Asia '03) (CD-ROM), 4 Pages, 2003/00
Utilization of bio-resources by radiation has been investigated for recycling the natural resources and reducing the environmental pollution. Polysaccharides such as chitosan and sodium alginate were easily degraded by irradiation and induced various kinds of biological activities, i.g. anti-microbial activity, promotion of plant growth, suppression of heavy metal stress, phytoalexins induction. Radiation degraded chitosan was effective to enhance the growth of plants in tissue culture. It was demonstrated that the liquid sample irradiation system using low energy EB was effective for the preparation of degraded polysaccharides. Methylcellulose (MC) can be crosslinked under certain radiation condition as same as carboxymethylcellulose (CMC) and produced the biodegradable hydrogel for medical and agricultural use. Treatment of soybean seeds by low energy EB enhanced the growth and the number of rhizobia on the root.
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:18 Percentile:73.04(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.
Harada, Masahide; Teshigawara, Makoto; Kai, Tetsuya; Sakata, Hideaki*; Watanabe, Noboru; Ikeda, Yujiro
JAERI-Research 2001-016, 32 Pages, 2001/03
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.
Meigo, Shinichiro; Maekawa, Fujio; Kasugai, Yoshimi; Nakashima, Hiroshi; Ikeda, Yujiro; Watanabe, Noboru; Ino, Takashi*; Sato, Setsuo*; ASTE Collaboration
JAERI-Conf 2001-002, p.941 - 954, 2001/03
no abstracts in English
Sobajima, Makoto
JAERI-Review 99-011, 200 Pages, 1999/03
no abstracts in English
Nakao, Noriaki*; Nakashima, Hiroshi; Nakao, Makoto*; Sakamoto, Yukio; Nakane, Yoshihiro; ; Tanaka, Shunichi; Nakamura, Takashi*
JAERI-Data/Code 98-013, 46 Pages, 1998/03
no abstracts in English
; Nakao, Noriaki*; Tanaka, Shunichi; Nakamura, Takashi*; Shin, Kazuo*; Tanaka, Susumu; Meigo, Shinichiro; Nakane, Yoshihiro; Takada, Hiroshi; Sakamoto, Yukio; et al.
JAERI-Data/Code 96-005, 46 Pages, 1996/03
no abstracts in English