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AuGe ( = Y, Gd-Tm, and Lu)Kurumaji, Takashi*; Gen, Masaki*; Kito, Shunsuke*; Ikeuchi, Kazuhiko*; Nakamura, Mitsutaka; Ikeda, Akihiko*; Arima, Takahisa*
Journal of Alloys and Compounds, 947, p.169475_1 - 169475_8, 2023/06
Times Cited Count：1 Percentile：48.82(Chemistry, Physical)Uchida, Shunsuke; Hanawa, Satoshi; Nishiyama, Yutaka; Nakamura, Takehiko; Sato, Tomonori; Tsukada, Takashi; Kysela, J.*
Nuclear Technology, 183(1), p.119 - 135, 2013/07
Times Cited Count：5 Percentile：38.34(Nuclear Science & Technology)In-pile loop experiments are one of the key technologies which can provide an understanding of corrosion behaviors of structural materials in nuclear power plants (NPPs). The experiments should be supported not only by reliable measurement tools to confirm corrosive conditions under neutron and 
ray irradiations but also by theoretical models for extrapolating the measured data to predict corrosion behaviors in NPPs. The relationships among electrochemical corrosion potential (ECP), metal surface conditions, exposure time and other environmental conditions have been determined from in situ measurements of corrosion behaviors of stainless steel specimens exposed to H
O and O in high temperature water. Based on the relationships, a model to evaluate ECP of stainless steel was developed by coupling an electrochemical model and a double oxide layer model. Major conclusions obtained from the evaluation model are as follows. (1) The difference in ECP behaviors of the specimens exposed to HO and O were mainly from the thickness and developing rate of the inner oxide layers. (2) Calculated ECP behaviors, e.g., the different responses to HO and O and hysteresis and memory effects, agreed with the measured ones. (3) Neutron exposure might decrease ECP due to radiation-induced diffusion in the oxide layer. The ECP evaluation model will be applied to evaluation of corrosive conditions in the JMTR in-pile loop.
Hanawa, Satoshi; Nakamura, Takehiko; Uchida, Shunsuke; Kus, P.*; Vsolak, R.*; Kysela, J.*; Sakai, Masanori*
Nuclear Technology, 183(1), p.136 - 148, 2013/07
Times Cited Count：2 Percentile：18.55(Nuclear Science & Technology)no abstracts in English
ray in in-pile loop and their data evaluation by water radiolysis calculationsHanawa, Satoshi; Nakamura, Takehiko; Uchida, Shunsuke; Kus, P.*; Vsolak, R.*; Kysela, J.*
Proceedings of 2010 Nuclear Plant Chemistry Conference (NPC 2010)/8th International Radiolysis, Electrochemistry & Materials Performance Workshop (CD-ROM), 10 Pages, 2010/10
In order to establish reliable electrochemical corrosion potential (ECP) sensors for applying in reactor core peripherals of power plants, performance tests of sensors under irradiation were carried out in the in-pile loop of the experimental reactor, LVR-15, at the Nuclear Research Institute (NRI) in Czech Republic. Responses of different kinds of sensors under neutron and irradiation conditions have been compared each other. Corrosive conditions along the in-pile loop were calculated by water radiolysis calculation code, WRAC-J and calculated corrosive conditions were compared with the measured results. As a result of the evaluation, it was confirmed that the ECP sensors could be applied to irradiation conditions of reactor peripherals, while the water radiolysis model could be also applied for evaluation of corrosive conditions of reactor peripherals.
Hanawa, Satoshi; Nakamura, Takehiko; Uchida, Shunsuke; Kus, P.*; Vsolak, R.*; Kysela, J.*
Proceedings of 2010 Nuclear Plant Chemistry Conference (NPC 2010)/8th International Radiolysis, Electrochemistry & Materials Performance Workshop (CD-ROM), 10 Pages, 2010/10
In-pile ECP measurements data was evaluated by water radiolysis calculations. The data was obtained by using in-pile loop in an experimental reactor, LVR-15, at the Nuclear Research Institute (NRI) in Czech Republic. Three types of ECP sensors, a Pt electrode, an Ag/AgCl sensor and a zirconia membrane sensor containing Ag/AgO were used at several levels of the irradiation rig at various neutron flux and rates. Concentration of chemical species along the water flow was calculated by a radiolysis code, WRAC-J. The radiolysis calculation results were transferred to an ECP model. In the model, anodic and cathodic current densities were calculated with combination of an electrochemistry model and an oxide film growth model. The measured ECP data were compared with the radiolysis/ECP calculation results, and applicability of radiolysis model was confirmed.
Tobita, Kenji; Nishio, Satoshi*; Enoeda, Mikio; Nakamura, Hirofumi; Hayashi, Takumi; Asakura, Nobuyuki; Uto, Hiroyasu; Tanigawa, Hiroyasu; Nishitani, Takeo; Isono, Takaaki; et al.
JAEA-Research 2010-019, 194 Pages, 2010/08
JAEA-Research-2010-019-01.pdf:48.47MBJAEA-Research-2010-019-02.pdf:19.4MB
This report describes the results of the conceptual design study of the SlimCS fusion DEMO reactor aiming at demonstrating fusion power production in a plant scale and allowing to assess the economic prospects of a fusion power plant. The design study has focused on a compact and low aspect ratio tokamak reactor concept with a reduced-sized central solenoid, which is novel compared with previous tokamak reactor concept such as SSTR (Steady State Tokamak Reactor). The reactor has the main parameters of a major radius of 5.5 m, aspect ratio of 2.6, elongation of 2.0, normalized beta of 4.3, fusion out put of 2.95 GW and average neutron wall load of 3 MW/m
. This report covers various aspects of design study including systemic design, physics design, torus configuration, blanket, superconducting magnet, maintenance and building, which were carried out increase the engineering feasibility of the concept.
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
Sakanaka, Shogo*; Akemoto, Mitsuo*; Aoto, Tomohiro*; Arakawa, Dai*; Asaoka, Seiji*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; et al.
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2338 - 2340, 2010/05
Future synchrotron light source using a 5-GeV energy recovery linac (ERL) is under proposal by our Japanese collaboration team, and we are conducting R&D efforts for that. We are developing high-brightness DC photocathode guns, two types of cryomodules for both injector and main superconducting (SC) linacs, and 1.3 GHz high CW-power RF sources. We are also constructing the Compact ERL (cERL) for demonstrating the recirculation of low-emittance, high-current beams using above-mentioned critical technologies.
Osakabe, Masaki*; Shinohara, Koji; Toi, Kazuo*; Todo, Yasushi*; Hamamatsu, Kiyotaka; Murakami, Sadayoshi*; Yamamoto, Satoshi*; Idomura, Yasuhiro; Sakamoto, Yoshiteru; Tanaka, Kenji*; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 85(12), p.839 - 842, 2009/12
no abstracts in English
Tobita, Kenji; Nishio, Satoshi; Enoeda, Mikio; Kawashima, Hisato; Kurita, Genichi; Tanigawa, Hiroyasu; Nakamura, Hirofumi; Honda, Mitsuru; Saito, Ai*; Sato, Satoshi; et al.
Nuclear Fusion, 49(7), p.075029_1 - 075029_10, 2009/07
Times Cited Count：139 Percentile：97.7(Physics, Fluids & Plasmas)Recent design study on SlimCS focused mainly on the torus configuration including blanket, divertor, materials and maintenance scheme. For vertical stability of elongated plasma and high beta access, a sector-wide conducting shell is arranged in between replaceable and permanent blanket. The reactor adopts pressurized-water-cooled solid breeding blanket. Compared with the previous advanced concept with supercritical water, the design options satisfying tritium self-sufficiency are relatively scarce. Considered divertor technology and materials, an allowable heat load to the divertor plate should be 8 MW/m or lower, which can be a critical constraint for determining a handling power of DEMO (a combination of alpha heating power and external input power for current drive).
Ohashi, Hayato*; Suda, Shintaro*; Tanuma, Hajime*; Fujioka, Shinsuke*; Nishimura, Hiroaki*; Nishihara, Katsunobu*; Kai, Takeshi; Sasaki, Akira; Sakaue, Hiroyuki*; Nakamura, Nobuyuki*; et al.
Journal of Physics; Conference Series, 163, p.012071_1 - 012071_4, 2009/06
Times Cited Count：7 Percentile：89.22(Physics, Multidisciplinary)Extreme ultra-violet (EUV) emission spectra of multiply charged tin ions were measured in the wavelength range of 10-22 nm following charge exchange collisions or the electron impact excitation of tin ions. In charge exchange collisions, we observed both the resonance lines and the emission lines corresponding to the transitions between the excited states. On the other hand, we observed mainly the resonance lines in the electron impact experiments. We can distinguish the resonance lines from other emission lines in the charge exchange spectrum by comparison with the emission lines in the electron impact spectrum.
Idomura, Yasuhiro; Yoshida, Maiko; Yagi, Masatoshi*; Tanaka, Kenji*; Hayashi, Nobuhiko; Sakamoto, Yoshiteru; Tamura, Naoki*; Oyama, Naoyuki; Urano, Hajime; Aiba, Nobuyuki; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 84(12), p.952 - 955, 2008/12
no abstracts in English
Takenaga, Hidenobu; Ogawa, Yuichi*; Takizuka, Tomonori; Yagi, Masatoshi*; Yamada, Hiroshi*; Sakamoto, Yoshiteru; Toi, Kazuo*; Fukuda, Takeshi*; Fukuyama, Atsushi*; Fujita, Takaaki; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 84(7), p.465 - 467, 2008/07
no abstracts in English
Kawahata, Kazuo*; Kawano, Yasunori; Kusama, Yoshinori; Mase, Atsushi*; Sasao, Mamiko*; Ide, Shunsuke; Oikawa, Toshihiro; Suzuki, Takahiro; Takase, Yuichi*; Nakamura, Yukio*; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 84(5), p.297 - 298, 2008/05
no abstracts in English
Sasao, Mamiko*; Kusama, Yoshinori; Kawano, Yasunori; Kawahata, Kazuo*; Mase, Atsushi*; Sugie, Tatsuo; Fujita, Takaaki; Fukuda, Takeshi*; Fukuyama, Atsushi*; Sakamoto, Yoshiteru; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 83(9), p.779 - 782, 2007/09
This is a report of highlights from 2007 spring meetings of seven Topical Groups (TG) of International Tokamak Physics Activity (ITPA). In each meeting, high priority issues in physics of International Thermonuclear Experimental Reactor (ITER) and other burning plasma experiments have been discussed and investigated. Twenty-seven scientists from Japan have participated in those meetings. Dates and places of the meetings are shown below. (1) Diagnostics TG: 26-30 March, Princeton (USA), (2) Transport Physics TG: 7-10 May, Lausanne (Switzerland), (3) Confinement Database and Modeling TG: 7-10 May, Lausanne (Switzerland), (4) Edge Pedestal Physics TG: 7-10 May, Garching (Germany) (5) Steady State Operation TG: 9-11 May, Daejeon (South Korea), (6)MHD TG: 21-24 May, San Diego (USA), (7) Scrape-off-layer and Divertor Physics TG: 7-10 May, Garching (Germany).
Tobita, Kenji; Nishio, Satoshi; Sato, Masayasu; Sakurai, Shinji; Hayashi, Takao; Shibama, Yusuke; Isono, Takaaki; Enoeda, Mikio; Nakamura, Hirofumi; Sato, Satoshi; et al.
Nuclear Fusion, 47(8), p.892 - 899, 2007/08
Times Cited Count：57 Percentile：86.53(Physics, Fluids & Plasmas)The concept for a compact DEMO reactor named "SlimCS" is presented. Distinctive features of the concept is low aspect ratio (
= 2.6) and use of a reduced-size center solenoid (CS) which has a function of plasma shaping rather than poloidal flux supply. The reduced-size CS enables us to introduce a thin toroidal field (TF) coil system which contributes to reducing the weight and construction cost of the reactor. SlimCS is as compact as advanced commercial reactor designs such as ARIES-RS and produces 1 GWe in spite of moderate requirements for plasma parameters. Merits of low-, i.e. vertical stability for high elongation and high beta limit are responsible for such reasonable physics requirements.
Watanabe, Hirofumi*; Nakamura, Nobuyuki*; Kato, Daiji*; Nakano, Tomohide; Otani, Shunsuke*
Plasma and Fusion Research (Internet), 2, p.027_1 - 027_3, 2007/06
X-ray spectra from highly charged W ions have been observed in the interaction with an electron beam at the energies ranged from 14 to 1.5 keV by using the Tokyo-EBIT. In this energy range, resonant X-ray transitions at around 9 keV are predominantly taken place through dielectronic recombination processes. The measured spectra are compared with the theoretical calculation with HULLAC.
Kawahata, Kazuo*; Kawano, Yasunori; Kusama, Yoshinori; Mase, Atsushi*; Sasao, Mamiko*; Sugie, Tatsuo; Fujita, Takaaki; Fukuda, Takeshi*; Fukuyama, Atsushi*; Sakamoto, Yoshiteru; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 83(2), p.195 - 198, 2007/02
no abstracts in English
Asakura, Nobuyuki; Kato, Takako*; Nakano, Tomohide; Takamura, Shuichi*; Tanabe, Tetsuo*; Iio, Shunji*; Nakajima, Noriyoshi*; Ono, Yasushi*; Ozeki, Takahisa; Takechi, Manabu; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 82(7), p.448 - 450, 2006/07
no abstracts in English
Sakamoto, Yoshiteru; Toi, Kazuo*; Fukuda, Takeshi*; Fukuyama, Atsushi*; Fujita, Takaaki; Ogawa, Yuichi*; Takizuka, Tomonori; Takenaga, Hidenobu; Yagi, Masatoshi*; Yamada, Hiroshi*; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 82(2), p.109 - 110, 2006/02
no abstracts in English
