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Hayashi, Takao; Sakurai, Shinji; Sakasai, Akira; Shibanuma, Kiyoshi; Kono, Wataru*; Onawa, Toshio*; Matsukage, Takeshi*
Fusion Engineering and Design, 101, p.180 - 185, 2015/12
Times Cited Count:5 Percentile:36.53(Nuclear Science & Technology)Remote pipe welding tool accessing from inside pipe has been newly developed for JT-60SA. Remote handling (RH) system is necessary for the maintenance and repair of in-vessel components such as lower divertor cassettes in JT-60SA. Cooling pipes, which connects between the divertor cassette and the vacuum vessel with bellows are required to be cut and welded in the vacuum vessel by RH system. The available space for RH system is very limited inside the vacuum vessel, especially around the divertor cassettes. Thus, the cooling pipes are required to be cut and weld from the inside in the vacuum vessel. The inner diameter, thickness and material of the cooling pipe are 54.2 mm, 2.8 mm and SUS316L, respectively. An upper pipe connected to the divertor cassette has a jut on the edge to fill the gap between pipes. Owing to the jut and two-times welding, the welding tool achieved the maximum allowable gap of 0.7 mm.
Saigusa, Mikio*; Oyama, Gaku*; Matsubara, Fumiaki*; Takii, Keita*; Sai, Takuma*; Kobayashi, Takayuki; Moriyama, Shinichi
Fusion Engineering and Design, 96-97, p.577 - 582, 2015/10
Times Cited Count:6 Percentile:42.50(Nuclear Science & Technology)A wideband polarizer has been developed for an ECCD system in JT-60SA. The groove depth of the mirrors installed in miter bends were optimized for two frequencies (110 GHz and 138 GHz) by numerical simulations. All surfaces of Poincare spheres were covered at both of the frequencies in low power test. The thermal stress of polarizer were estimated by the numerical simulations. The twister polarizer has been tested up to 0.24 MW during 3 s at 110 GHz.
Isobe, Kanetsugu; Kawamura, Yoshinori; Iwai, Yasunori; Oyaizu, Makoto; Nakamura, Hirofumi; Suzuki, Takumi; Yamada, Masayuki; Edao, Yuki; Kurata, Rie; Hayashi, Takumi; et al.
Fusion Engineering and Design, 98-99, p.1792 - 1795, 2015/10
Times Cited Count:0 Percentile:0.00(Nuclear Science & Technology)Activities on Broader Approach (BA) were started in 2007 on the basis of the Agreement between the Government of Japan and the EURATOM. The period of BA activities consist of Phase1 and Phase2 dividing into Phase 2-1 (2010-2011), Phase 2-2 (2012-2013) and Phase 2-3 (2014-2016). Tritium technology was chosen as one of important R&D issues to develop DEMO plant. R&D activities of tritium technology on BA consist of four tasks. Task-1 is to prepare and maintain the tritium handling facility in Rokkasho BA site in Japan. Task 2, 3 and 4 are main R&D activities for tritium and these are focused on: Task-2) Development of tritium accountancy technology, Task-3) Development of basic tritium safety research, Task-4) Tritium durability test. R&D activities of tritium technology in Phase 2-2 were underway successfully and closed in 2013.
Ferro, A.*; Gaio, E.*; Novello, L.*; Matsukawa, Makoto; Shimada, Katsuhiro; Kawamata, Yoichi; Takechi, Manabu
Fusion Engineering and Design, 98-99, p.1053 - 1057, 2015/10
Times Cited Count:3 Percentile:23.54(Nuclear Science & Technology)Lampasi, A.*; Zito, P.*; Coletti, A.*; Novello, L.*; Matsukawa, Makoto; Shimada, Katsuhiro; Burini, F.*; Kuate-Fone, Y.*; Taddia, G.*; Tenconi, S.*
Fusion Engineering and Design, 98-99, p.1098 - 1102, 2015/10
Times Cited Count:11 Percentile:63.96(Nuclear Science & Technology)Zito, P.*; Lampasi, A.*; Coletti, A.*; Novello, L.*; Matsukawa, Makoto; Shimada, Katsuhiro; Cinarelli, D.*; Portesine, M.*; Dorronsoro, A.*; Vian, D.*
Fusion Engineering and Design, 98-99, p.1191 - 1196, 2015/10
Times Cited Count:14 Percentile:72.01(Nuclear Science & Technology)Maistrello, A.*; Gaio, E.*; Novello, L.*; Matsukawa, Makoto; Yamauchi, Kunihito
Fusion Engineering and Design, 98-99, p.1109 - 1112, 2015/10
Times Cited Count:9 Percentile:56.63(Nuclear Science & Technology)Novello, L.*; Baulaigue, O.*; Coletti, A.*; Dumas, N.*; Ferro, A.*; Gaio, E.*; Lampasi, A.*; Maistrello, A.*; Matsukawa, Makoto; Shimada, Katsuhiro; et al.
Fusion Engineering and Design, 98-99, p.1122 - 1126, 2015/10
Times Cited Count:18 Percentile:78.00(Nuclear Science & Technology)Kizu, Kaname; Murakami, Haruyuki; Natsume, Kyohei; Tsuchiya, Katsuhiko; Koide, Yoshihiko; Yoshida, Kiyoshi; Obana, Tetsuhiro*; Hamaguchi, Shinji*; Takahata, Kazuya*
Fusion Engineering and Design, 98-99, p.1094 - 1097, 2015/10
Times Cited Count:6 Percentile:42.50(Nuclear Science & Technology)Current feeder and Coil Terminal Box (CTB) for the superconducting magnets for JT-60SA were designed. Copper busbar from power supply is connected to the High Temperature Superconductor Current Lead (HTS CL), which is installed on the vacuum vessel called CTB. The superconducting current feeder is connected to the cold end of HTS CL, and is led to main cryostat for magnets. Trial manufacturing of crank shaped feeder to reduce the thermal stress was performed. The small tool which can connect soldering joint with vertical direction was developed. Insulation materials made by manufacturing condition showed sufficient shear stress. Since the all manufacturing process concerned was confirmed, the production of current feeder and CTB can be started.
Tsuru, Daigo; Sakurai, Shinji; Nakamura, Shigetoshi; Ozaki, Hidetsugu; Seki, Yohji; Yokoyama, Kenji; Suzuki, Satoshi
Fusion Engineering and Design, 98-99, p.1403 - 1406, 2015/10
Times Cited Count:4 Percentile:30.44(Nuclear Science & Technology)Ezato, Koichiro; Suzuki, Satoshi; Seki, Yohji; Mori, Kensuke; Yokoyama, Kenji; Escourbiac, F.*; Hirai, Takeshi*; Kuznetsov, V.*
Fusion Engineering and Design, 98-99, p.1281 - 1284, 2015/10
Times Cited Count:47 Percentile:96.38(Nuclear Science & Technology)Japan Atomic Energy Agency (JAEA) is now devoting to development of Full-W ITER divertor outer vertical target (OVT), especially, PFU that needs to withstand the repetitive heat load as high as 20MW/m. JAEA have succeeded in demonstrating that the soundness of a bonding technology is sufficient for the full-W ITER divertor. For the development of bonding technology, the load carrying capability test on the W monoblock with a leg attachment to an OVT support structure was carried out and shows that the attachment can withstand against the uniaxial load more than 20 kN which is three times higher than the IO requirement. JAEA manufactured 6 small-scale mock-ups and tested under the repetitive heat load of 10 and 20 MW/m
to examine the durability of the divertor structure including W tile bonding and the cooling tube. All of the mock-ups could survived 5000 cycles at 10 MW/m
and 1000 cycles 20 MW/m
with no failure such as debonding of the W tile and water leak from the cooling tube. The number of cycles at 20 MW/m
is three times longer than the requirement of ITER divertor.
Iwai, Yasunori
Fusion Engineering and Design, 98-99, p.1796 - 1799, 2015/10
Times Cited Count:5 Percentile:36.53(Nuclear Science & Technology)Hydrophobic platinum catalysts have been widely applied in the field of nuclear fusion for the exchange reactions of hydrogen isotopes between hydrogen and vapor in the water detritiation system, and for the oxidation of tritium on the atmospheric detritiation system. Hydrophobic platinum catalysts are hardly susceptible to water mist and water vapor. Hydrophobic platinum catalysts are produced by supporting platinum directly on hydrophobic polymer beads. For the hydrophobic polymer, styrene - divinyl benzene (SDB) has been applied in Japan. It can be pointed out that the upgrade in catalytic activity of hydrophobic catalyst is expected to downsize the catalytic reactor based on a hard look at a large increase in flow rate in future. The upgrade in catalytic activity of two types of commercial Pt/SDB catalysts was found when they were irradiated with electron beams. After irradiation with electron beams, the catalytic activity was evaluated by means of overall reaction rate constant for the oxidation of tritium. The overall reaction rate constant increased as increase in dose. The constant showed the peak value in the dose between 500 to 1000 kGy. After the peak, the constant decreased as increase in dose. The overall reaction rate constant at the peak was 6 times larger than that evaluated with unirradiated. The mechanical strength of irradiated Pt/SDB kept sound until 1500 kGy. The irradiation is a promising method to the upgrading in catalytic activity of Pt/SDB catalyst.
Yamamoto, Tsuyoshi; Hashimoto, Yasunori*; Kitazawa, Sin-iti; Yatsuka, Eiichi; Hatae, Takaki; Sugie, Tatsuo; Ogawa, Hiroaki; Takeuchi, Masaki; Kawano, Yasunori; Itami, Kiyoshi
Fusion Engineering and Design, 96-97, p.1012 - 1016, 2015/10
Times Cited Count:5 Percentile:36.53(Nuclear Science & Technology)Japan Domestic Agency (JADA) is responsible for six diagnostic systems in the ITER project. We have successfully developed an instrumentation and control (I&C) system for the diagnostic systems. The I&C system manages internal operations for measurement such as health checks of sensors, configuration of measurement parameters, and consistency checks between measurement parameters. We developed a conversion tool to convert operational flowcharts to EPICS records. The sequencing management function coordinates the execution of operation steps by monitoring changes in the record values. It was designed so that the relationship between the records and steps is determined automatically according to the flowcharts as much as possible. We validated the performance of the I&C system for the thermocouple measurement system, and are continuing the development of even more complex I&C systems for other JADA diagnostic systems.
Yoshida, Masafumi; Hanada, Masaya; Kojima, Atsushi; Kashiwagi, Mieko; Grisham, L. R.*; Hatayama, Akiyoshi*; Shibata, Takanori*; Yamamoto, Takashi*; Akino, Noboru; Endo, Yasuei; et al.
Fusion Engineering and Design, 96-97, p.616 - 619, 2015/10
Times Cited Count:13 Percentile:69.58(Nuclear Science & Technology)In JT-60 Super Advanced for the fusion experiment, 22A, 100s negative ions are designed to be extracted from the world largest ion extraction area of 450 mm 1100 mm. One of the key issues for producing such as high current beams is to improve non-uniform production of the negative ions. In order to improve the uniformity of the negative ions, a tent-shaped magnetic filter has newly been developed and tested for JT-60SA negative ion source. The original tent-shaped filter significantly improved the logitudunal uniformity of the extracted H
ion beams. The logitudinal uniform areas within a
10 deviation of the beam intensity were improved from 45% to 70% of the ion extraction area. However, this improvement degrades a horizontal uniformity. For this, the uniform areas was no more than 55% of the total ion extraction area. In order to improve the horizontal uniformity, the filter strength has been reduced from 660 Gasus
cm to 400 Gasus
cm. This reduction improved the horizontal uniform area from 75% to 90% without degrading the logitudinal uniformity. This resulted in the improvement of the uniform area from 45% of the total ion extraction areas. This improvement of the uniform area leads to the production of a 22A H
ion beam from 450 mm
1100 mm with a small amount increase of electron current of 10%. The obtained beam current fulfills the requirement for JT-60SA.
Tanigawa, Hiroyasu; Ozawa, Kazumi; Morisada, Yoshiaki*; Noh, S.*; Fujii, Hidetoshi*
Fusion Engineering and Design, 98-99, p.2080 - 2084, 2015/10
Times Cited Count:14 Percentile:72.01(Nuclear Science & Technology)The vacuum plasma spray (VPS) technique has been investigated as the most practical method to form Tungsten (W) layer as a plasma facing material in fusion devices. The issues are the thermal conductivity and the strength of VPS-W, i.e., the thermal conductivity of VPS-W were significantly lower than that of the bulk W, and the hardness of VPS-W is much less than that of the bulk W. These are mainly caused by the porous structure of VPS-W. In order to solve these issues, friction stir processing (FPS) was applied on VPS-W in this study. It was suggested that FSP can contribute to significant improvement both in mechanical and thermal properties of VPS-W coating.
Matsunaga, Go; Takechi, Manabu; Sakurai, Shinji; Suzuki, Yasuhiro*; Ide, Shunsuke; Urano, Hajime
Fusion Engineering and Design, 98-99, p.1113 - 1117, 2015/10
Times Cited Count:20 Percentile:81.00(Nuclear Science & Technology)Kanemura, Takuji; Kondo, Hiroo; Furukawa, Tomohiro; Hirakawa, Yasushi; Hoashi, Eiji*; Yoshihashi, Sachiko*; Horiike, Hiroshi*; Wakai, Eiichi
Fusion Engineering and Design, 98-99, p.1991 - 1997, 2015/10
Times Cited Count:17 Percentile:76.03(Nuclear Science & Technology)A high-speed (15 m/s) liquid lithium jet is planned to be utilized as the target of two 40 MeV - 125 mA deuteron beams in the International Fusion Materials Irradiation Facility (IFMIF). The target thickness is required to be maintained within 25 1 mm under a vacuum condition of 10
Pa. This paper reports the result of measurements of the Li-target thickness under the IFMIF condition (Li speed of 10 to 20 m/s, vacuum pressure of 10
Pa, Li temperature of 250
C) in the EVEDA Li Test Loop. The target thickness was found to be 26.08 mm on average at the speed of 15 m/s at the center of the IFMIF beam footprint. As for temporal fluctuation, average and maximum amplitude at the same measurement position were 0.26 and 1.45 mm, respectively, and more than 99.7% of all amplitudes measured were within the design requirement. Therefore, it was found that the Li target fulfilled the required stability for IFMIF.
Konno, Chikara; Ochiai, Kentaro; Sato, Satoshi; Ota, Masayuki
Fusion Engineering and Design, 98-99, p.2178 - 2181, 2015/10
Times Cited Count:8 Percentile:52.35(Nuclear Science & Technology)We have analyzed the iron and concrete shielding experiments with the 40 and 65 MeV neutron sources at TIARA in Japan Atomic Energy Agency with the latest high-energy nuclear data libraries, JENDL/HE-2007, ENDF/B-VII.1 and FENDL-3.0. The Monte Carlo code MCNP-5 and ACE files of JENDL/HE-2007, ENDF/B-VII.1 and FENDL-3.0, which were supplied from JAEA, BNL and IAEA, respectively, were used for this analysis. The followings are found out from the results. (1) The calculations with JENDL/HE-2007 agree with all the measured ones well; (2) Those with ENDF/B-VII.1 tend to overestimate the measured ones with the thickness of the assemblies largely; (3) Those with FENDL-3.0 agree with the measured ones well for the iron experiment, while they overestimate the measured ones well for the concrete experiment largely. Some data in ENDF/B-VII.1 and FENDL-3.0 should be revised.
Wakai, Eiichi; Kikuchi, Takayuki; Kim, B.*; Kimura, Akihiko*; Nogami, Shuhei*; Hasegawa, Akira*; Nishimura, Arata*; Soldaini, M.*; Yamamoto, Michiyoshi*; Knaster, J.*
Fusion Engineering and Design, 98-99, p.2089 - 2093, 2015/10
Times Cited Count:17 Percentile:78.00(Nuclear Science & Technology)Furukawa, Tomohiro; Hirakawa, Yasushi; Kondo, Hiroo; Kanemura, Takuji; Wakai, Eiichi
Fusion Engineering and Design, 98-99, p.2138 - 2141, 2015/10
Times Cited Count:13 Percentile:69.58(Nuclear Science & Technology)In the International Fusion Materials Irradiation Facility (IFMIF), a back plate of the target assembly will be exchanged during the in-service period. During the works, the lithium components will react chemically with the surrounding atmosphere. In this research, the chemical reaction of lithium in air, oxygen and nitrogen containing variable humidity at room temperature has been investigated to estimate the chemical reaction during the exchange works.