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Yasuda, Satoshi; Dio, W. A.*; Fukutani, Katsuyuki
Vacuum and Surface Science, 66(9), p.514 - 519, 2023/09
Monolayer graphene, representative of atomically thin crystals, has recently shown unexpectedly high proton and deuteron permeability under ambient conditions. It also permeates (filters) hydrogen (deuterium) isotope ion with high selectivity. These results suggest possible ways of developing novel and efficient hydrogen isotope gas enrichment techniques for manufacturing silicon semiconductors, optical fibers, drug development, nuclear fusion, and other related applications. And yet, despite its importance, experimental studies remain scarce and the separation mechanism contentious. Here, we introduce our recent findings on how quantum tunneling of hydrons through graphene could account for the high hydron selectivity of graphene.
Nakata, Kotaro*; Hasegawa, Takuma*; Oyama, Takahiro*; Miyakawa, Kazuya
Journal of Hydrology, 561, p.547 - 556, 2018/06
Times Cited Count:5 Percentile:25.66(Engineering, Civil)no abstracts in English
Ohira, Shigeru; Yamanishi, Toshihiko; Hayashi, Takumi
Journal of Nuclear Science and Technology, 43(4), p.354 - 360, 2006/04
Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)In this paper, expected operation scenarios for ITER and future fusion reactors from a viewpoint of an integrated isotope processing in a future D-T fusion rector are provided with comparisons of requirements for system design attributed to the operation scenarios, safety requirements, etc. Most of the basic requirements for fuel process of a D-T fusion reactor facility common are the same, but the design requirements coming from the individual operation scenarios of ITER and future demo reactors will differ. The system design requirements of the tritium plant taking care of various operations of ITER and a demo reactor are examined and compared. Due to the increase of tritium concentration in the coolant of a demo reactor by tritium permeation in the structural material of the in-vessel components operated at a temperature higher than that of ITER detritiation of coolant will be getting more important. Some important key parameters related to hydrogen isotope processing in future fusion reactors will be discussed.
Isobe, Kanetsugu; Nakamura, Hirofumi; Kaminaga, Atsushi; Tsuzuki, Kazuhiro; Higashijima, Satoru; Nishi, Masataka; Kobayashi, Yasunori*; Konishi, Satoshi*
Fusion Engineering and Design, 81(1-7), p.827 - 832, 2006/02
Times Cited Count:11 Percentile:60.07(Nuclear Science & Technology)Exhaust gas from JT-60U during experimental operation has been measured with Gas Chromatography (GC), and the gas exhaust characteristic from JT-60U on plasma discharge conditions has been investigated during the JT-60U experimental campaign in 2003-2004. During experimental operation of JT-60U, hydrogen isotope concentration strongly depended on the type of discharges such as high performance, long pulse and so on. On the other hand, impurity species, such as helium, hydrocarbon and carbon oxide, were detected during plasma discharges occasionally. During the experimental operation, plasma disruption remarkably tended to produce high concentration impurities. Glow discharge and Taylor discharge for wall conditioning also produced impurities. In the case of normal plasma, impurity was detected and high performance plasma, such as high plasma, tended to produce high concentration impurities. This result indicated that impurities concentration might be higher in the case of normal plasma in ITER, because of its high performance.
Oya, Yasuhisa*; Hirohata, Yuko*; Tanabe, Tetsuo*; Shibahara, Takahiro*; Kimura, Hiromi*; Oyaizu, Makoto*; Arai, Takashi; Masaki, Kei; Goto, Yoshitaka*; Okuno, Kenji*; et al.
Fusion Engineering and Design, 75-79, p.945 - 949, 2005/11
Times Cited Count:9 Percentile:52.95(Nuclear Science & Technology)no abstracts in English
Iwai, Yasunori; Yamanishi, Toshihiko; Nishi, Masataka
JAERI-Tech 2005-045, 38 Pages, 2005/08
no abstracts in English
Hirohata, Yuko*; Shibahara, Takahiro*; Tanabe, Tetsuo*; Oya, Yasuhisa*; Arai, Takashi; Goto, Yoshitaka*; Masaki, Kei; Yagyu, Junichi; Oyaizu, Makoto*; Okuno, Kenji*; et al.
Fusion Science and Technology, 48(1), p.557 - 560, 2005/07
Times Cited Count:3 Percentile:24.15(Nuclear Science & Technology)no abstracts in English
Masaki, Kei
Nihon Genshiryoku Gakkai-Shi, 46(12), p.834 - 837, 2004/12
no abstracts in English
Miya, Naoyuki; Tanabe, Tetsuo*; Nishikawa, Masabumi*; Okuno, Kenji*; Hirohata, Yuko*; Oya, Yasuhisa*
Journal of Nuclear Materials, 329-333(1), p.74 - 80, 2004/08
Times Cited Count:12 Percentile:61.35(Materials Science, Multidisciplinary)no abstracts in English
Iwakiri, Hirotomo*; Yoshida, Naoaki*; Uchida, Munenori*; Kawamura, Hiroshi
JAERI-Conf 2004-006, p.220 - 224, 2004/03
no abstracts in English
Kawamura, Yoshinori; Konishi, Satoshi; Nishi, Masataka
Fusion Science and Technology, 45(1), p.33 - 40, 2004/01
Times Cited Count:25 Percentile:81.85(Nuclear Science & Technology)Aiming at realization of the efficient blanket tritium recovery system of a fusion reactor, research and development of the hydrogen pump using the proton conductor are furthered. One of the advantages of the system using the hydrogen pump is concurrent processing of hydrogen isotopes and water vapor by one component. In this work, experimental research on the hydrogen extraction characteristic in a water molecule was performed with the hydrogen pump using SrCeYbO. In hydrogen extraction from a water molecule, application of the threshold, voltage corresponding to the decomposition energy of water, is necessary. The observed threshold was about 500-600mV at 873K and decreased with the increase in water vapor pressure. About pumping of H-HO mixture gas, the permeation of H anteceded water decomposition, and the threshold of water decomposition increased with the increase in hydrogen partial pressure. In order to process concurrently, application of fairly higher voltage is expected to be necessary.
Oya, Yasuhisa*; Morimoto, Yasutomi*; Oyaizu, Makoto*; Hirohata, Yuko*; Yagyu, Junichi; Miyo, Yasuhiko; Goto, Yoshitaka*; Sugiyama, Kazuyoshi*; Okuno, Kenji*; Miya, Naoyuki; et al.
Physica Scripta, T108, p.57 - 62, 2004/00
no abstracts in English
Laesser, R.*; Gruenhagen, S.*; Kawamura, Yoshinori
Fusion Engineering and Design, 69(1-4), p.813 - 817, 2003/09
Times Cited Count:15 Percentile:68.93(Nuclear Science & Technology)Various analytical techniques exist to determine the compositions of gases handled in the fuel cycle of future fusion machines. Gas chromatography was found to be the most appropriate method. The main disadvantages of conventional gas chromatography were the long retention times for the heavy hydrogen species of more than half an hour. Recent progress in the development of micro-gas chromatography has reduced these retention times to approximately 3 minutes. The usefulness of micro-gas chromatography for the analysis of hydrogen and impurity gas mixtures in the fuel cycle of future fusion machines is presented and the advantages and draw backs are discussed.
Aratono, Yasuyuki
Hamon, 13(3), p.168 - 172, 2003/07
Recent works on hydrogen abstractions by tritium atom and on recombination reactions of tritium and hydrogen atoms at low temperature(1-2K), which were carried out at JRR-3M by the authors, were introduced.
Oya, Yasuhisa*; Hirohata, Yuko*; Morimoto, Yasutomi*; Yoshida, Hajime*; Kodama, Hiroshi*; Kizu, Kaname; Yagyu, Junichi; Goto, Yoshitaka*; Masaki, Kei; Okuno, Kenji*; et al.
Journal of Nuclear Materials, 313-316, p.209 - 213, 2003/03
Times Cited Count:25 Percentile:82.76(Materials Science, Multidisciplinary)no abstracts in English
Higashijima, Satoru; Nakamura, Hirofumi; Horikawa, Toyohiko*; Kaminaga, Atsushi; Seki, Masami; Kubo, Hirotaka; Konishi, Satoshi; Tanabe, Tetsuo*
Proceedings of 30th EPS Conference on Controlled Fusion and Plasma Physics (CD-ROM), 4 Pages, 2003/00
no abstracts in English
Iwai, Yasunori; Yamanishi, Toshihiko; Ohira, Shigeru; Suzuki, Takumi; Shu, Wataru; Nishi, Masataka
Fusion Engineering and Design, 61-62, p.553 - 560, 2002/11
Times Cited Count:15 Percentile:67.64(Nuclear Science & Technology)no abstracts in English
Kawamura, Yoshinori; Konishi, Satoshi; Nishi, Masataka; Kakuta, Toshiya*
Fusion Science and Technology, 41(3), p.1035 - 1039, 2002/05
To establish the nuclear fusion reactor, tritium bred in the breeder blanket of the fusion reactor must be recovered effectively. The present authors have proposed the blanket tritium recovery system using the hydrogen pump with solid electrolyte membrane. Hydrogen isotopes including tritium can be separated from helium purge gas of the breeder blanket by the protonic conductor membrane which pumps out hydrogen isotopes selectively by applying a few potential difference between its faces. Perovskite-type ceramic such as SrCeYbO, is one of the candidate protonic conductor for hydrogen pump and its ionic hydrogen transportation properties have been investigated. Deuterium transportation properties have also been investigated to understand the isotope effect. Through the investigation up to now, the basic hydrogen isotope transportation property of SrCeYbO, its technical feasibility, and issues for further development toward the practical devices were revealed.
Arita, Tadaaki*; Yamanishi, Toshihiko; Iwai, Yasunori; Nishi, Masataka; Yamamoto, Ichiro*
Fusion Science and Technology, 41(3), p.1116 - 1120, 2002/05
no abstracts in English
Tominaga, Shinya*; Busnyuk, A.*; Matsushima, T.*; Yamaguchi, Kenji; Ono, Futaba*; Terai, Takayuki*; Yamawaki, Michio*
Fusion Science and Technology, 41(3), p.919 - 923, 2002/05
no abstracts in English