Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Shibata, Yoshihide*; Watanabe, Kiyomasa*; Ono, Noriyasu*; Okamoto, Masaaki*; Isayama, Akihiko; Kurihara, Kenichi; Oyama, Naoyuki; Nakano, Tomohide; Kawano, Yasunori; Matsunaga, Go; et al.
Plasma and Fusion Research (Internet), 6, p.1302136_1 - 1302136_4, 2011/10
no abstracts in English
Kurihara, Masayoshi*; Onoe, Jun*; Hirata, Masaru; Suzuki, Chikashi
Journal of Alloys and Compounds, 509(4), p.1152 - 1156, 2011/01
Times Cited Count:3 Percentile:24.21(Chemistry, Physical)The alloying behavior of transition metals (TMs) in solid -phase uranium (-U), which is expected to be used as fuel for next-generation nuclear reactors, is investigated using the discrete-variational Dirac-Fock-Slater molecular orbital method. Using a model cluster, U/TM, as the minimum unit of -U/TM alloys, we evaluate the d-orbital energy of the TM (Md), the bond order between the TM and U atoms, and the orbital overlap population (OOP) between the atomic orbitals of the TM and U atoms. We subsequently examine the effect of these quantities on the maximum solid solubility (MSS) of the -U/TM alloys. Md and the OOP (U 6d-TM d) exhibit good correlations with the MSS for -U/TM alloys, so that the interaction between the U-6d and TM-d atomic orbitals is found to play a key role in determining the MSS of the -U/TM alloys. The magnitude of the MSS can be explained in terms of the stabilization energy caused by U 6d-TM d orbital interactions for -U/TM alloys, which is affected by the Md and the OOP. The exponential dependence of the MSS on Md and the OOP is explained in terms of the equilibrium constant obtained using a substitution cluster model for -U/TM alloys. We also map the MSS of -U/TM alloys using the Md and the OOP as the alloying parameters. These results will assist the quantum design of nuclear fuel materials for other alloy systems besides the present alloy system.
Shibata, Yoshihide*; Watanabe, Kiyomasa*; Okamoto, Masaaki*; Ono, Noriyasu*; Isayama, Akihiko; Kurihara, Kenichi; Nakano, Tomohide; Oyama, Naoyuki; Kawano, Yasunori; Matsunaga, Go; et al.
Nuclear Fusion, 50(2), p.025015_1 - 025015_7, 2010/01
Times Cited Count:14 Percentile:52.54(Physics, Fluids & Plasmas)no abstracts in English
Yamaguchi, Taiki; Kawano, Yasunori; Fujieda, Hirobumi; Kurihara, Kenichi; Sugihara, Masayoshi*; Kusama, Yoshinori
Plasma Physics and Controlled Fusion, 50(4), p.045004_1 - 045004_15, 2008/04
The poloidal polarimeter will be installed in the International Thermonuclear Experimental Reactor (ITER) to measure the safety factor profile. The number of viewing chords is restricted to about 15 channels. Therefore optimization of the viewing chord arrangement is necessary to diagnose the accurate safety factor profile. In this study, we studied the optimum viewing chord arrangement for the equilibria of ITER operation scenarios using the equilibrium reconstruction. For the burning phase of inductive scenario, the error of the safety factor on the magnetic axis was 35% if the viewing chords are not arranged in the peripheral region. It was improved to 3% by arranging the viewing chord of the upper port to peripheral region. This arrangement was used for the reconstruction of the burning phase in the noninductive scenario and of the phase of the plasma current 3.5 MA in the inductive operation scenario. As the result, the accuracy does not decrease drastically.
Yamaguchi, Taiki; Kawano, Yasunori; Fujieda, Hirobumi; Kurihara, Kenichi; Sugihara, Masayoshi*; Kusama, Yoshinori
Plasma Physics and Controlled Fusion, 50(4), p.045004_1 - 045004_15, 2008/04
Times Cited Count:10 Percentile:38.41(Physics, Fluids & Plasmas)We have studied the viewing chord arrangement of the poloidal polarimeter in the International Thermonuclear Experimental Reactor (ITER). We have optimized the viewing chord arrangement based on the evaluation using a magnetohydrodynamic equilibrium reconstruction code. This reconstruction code has been developed in this study. We have successfully optimized viewing chord arrangements for three equilibria of the ITER operation scenario. The accuracy of the central safety factor within 3% has been achieved in each case. Furthermore, the viewing chord arrangement, which is optimized for the inductive operation scenario II at the start of the burn phase (S2-SOB), has been applied for other equilibria. As the result, the accuracy has not deteriorated drastically compared with the accuracy which is evaluated using the optimized arrangement for each equilibrium. The viewing chord arrangement for S2-SOB is proposed as the most promising candidate of the ITER poloidal polarimeter.
Kurihara, Masayoshi*; Hirata, Masaru; Onoe, Jun*; Nakamatsu, Hirohide*
Progress in Nuclear Energy, 50(2-6), p.549 - 555, 2008/03
Times Cited Count:1 Percentile:10.12(Nuclear Science & Technology)The alloying behavior of 4d and 5d transition metals (TMs) in -phase solid uranium (U) has been investigated using the discrete-variational Dirac-Fock-Slater (DV-DFS) method. We examined the d-orbital energy (Md value) of these TMs, the orbital overlap population (OOP) between the d-orbital of these TMs and the 5f or 6d orbital of -U, and the effective charge on each atom of the -U/TM alloy, and the effect of these parameters on alloying. It was found that the maximum solid solubility of TMs into -U was exponentially proportional to both the Md and the OOP (U5f-TMd and U6d-TMd). We found a good correlation between the MSS and Md, the effective charge, or OOP.
Takamura, Shuichi*; Kado, Shinichiro*; Fujii, Takashi*; Fujiyama, Hiroshi*; Takabe, Hideaki*; Adachi, Kazuo*; Morimiya, Osamu*; Fujimori, Naoji*; Watanabe, Takayuki*; Hayashi, Yasuaki*; et al.
Kara Zukai, Purazuma Enerugi No Subete, P. 164, 2007/03
no abstracts in English
Kurihara, Masayoshi*; Hirata, Masaru; Sekine, Rika*; Onoe, Jun*; Nakamatsu, Hirohide*
Journal of Nuclear Materials, 326(2-3), p.75 - 79, 2004/03
Times Cited Count:12 Percentile:61.61(Materials Science, Multidisciplinary)We have investigated the alloying behavior of g-uranium with 3d transition metals (TMs) using the relativistic discrete-variational Dirac-Fock-Slater (DV-DFS) method. The d-orbital energy (Md) as an alloying parameter well reproduces the alloying behavior of g- uranium metal with TMs: (1) in the case of a large Md value (Ti,V,Cr), the solubility of these TM elements in g-uranium becomes large; (2) in the case of a middle Md value (Mn,Fe,Co), the tendency to form a uranium intermetallic compound with these elements becomes stronger; (3) in the case of a small Md value (Cu), the alloying element is insoluble in g-uranium. The alloying behavior of g-uranium with TMs is also discussed in terms of other parameters such as electronegativity and metallic radius.
Kurihara, Masayoshi*; Hirata, Masaru; Sekine, Rika*; Onoe, Jun*; Nakamatsu, Hirohide*
Journal of Nuclear Materials, 281(2-3), p.140 - 145, 2000/10
Times Cited Count:3 Percentile:26.46(Materials Science, Multidisciplinary)no abstracts in English
Kurihara, Masayoshi*; Hirata, Masaru; Sekine, Rika*; Onoe, Jun*; Nakamatsu, Hirohide*; Mukoyama, Takeshi*; *
Journal of Alloys and Compounds, 283, p.128 - 132, 1999/00
Times Cited Count:10 Percentile:59.69(Chemistry, Physical)no abstracts in English
Azumi, Masafumi; Hasegawa, Mitsuru*; *; Kurihara, Kenichi; Nakamura, Yukiharu; Nishio, Satoshi; Shimomura, Yasuo; Shinya, K.*; Sugihara, Masayoshi; *; et al.
JAERI-M 92-041, 100 Pages, 1992/03
no abstracts in English
Sakurai, Satoshi; Hirata, Masaru; ; Usuda, Shigekazu; Abe, Jiro; ; Tachimori, Shoichi; ; Kurihara, Masayoshi; Kobayashi, Iwao
JAERI-M 90-059, 35 Pages, 1990/03
no abstracts in English
Yahata, Taneaki; *; Hirata, Masaru; Kurihara, Masayoshi
Proc. of the 1989 Joint Int. Waste Management Conf., Vol. 1, p.75 - 80, 1989/00
no abstracts in English
Yahata, Taneaki; Hirata, Masaru; *; Kurihara, Masayoshi
JAERI-M 88-233, 29 Pages, 1988/11
no abstracts in English
Yahata, Taneaki; *; Kurihara, Masayoshi
JAERI-M 88-008, 25 Pages, 1988/01
no abstracts in English
Yamaguchi, Taiki; Kawano, Yasunori; Fujieda, Hirobumi; Kurihara, Kenichi; Sugihara, Masayoshi*; Kusama, Yoshinori
no journal, ,
no abstracts in English
Onoe, Jun*; Kurihara, Masayoshi*; Hirata, Masaru; Suzuki, Chikashi
no journal, ,
Shibata, Yoshihide*; Watanabe, Kiyomasa*; Okamoto, Masaaki*; Ono, Noriyasu*; Isayama, Akihiko; Kurihara, Kenichi; Oyama, Naoyuki; Nakano, Tomohide; Kawano, Yasunori; Matsunaga, Go; et al.
no journal, ,
no abstracts in English
Shibata, Yoshihide*; Watanabe, Kiyomasa*; Ono, Noriyasu*; Okamoto, Masaaki*; Isayama, Akihiko; Kurihara, Kenichi; Oyama, Naoyuki; Nakano, Tomohide; Kawano, Yasunori; Matsunaga, Go; et al.
no journal, ,
no abstracts in English
Kondo, Emiko*; Kameari, Naoko*; Nakayama, Masayoshi*; Kurihara, Yasushi*; Akita, Yusuke; Tanikawa, Natsu*; Morita, Yasumasa*; Hase, Yoshihiro; Tanaka, Atsushi; Ishizaka, Hiroshi*
no journal, ,
no abstracts in English