Angular distribution of rays from a neutron-induced -wave resonance of Xe

Okudaira, Takuya*; Tani, Yuika*; Endo, Shunsuke; Doskow, J.*; Fujioka, Hiroyuki*; Hirota, Katsuya*; Kameda, Kento*; Kimura, Atsushi; Kitaguchi, Masaaki*; Luxnat, M.*; et al.

Physical Review C, 107(5), p.054602_1 - 054602_7, 2023/05

https://doi.org/10.1103/PhysRevC.107.054602

no abstracts in English

Angular distribution of rays from the -wave resonance of Sn

Koga, Jun*; Takada, Shusuke*; Endo, Shunsuke; Fujioka, Hiroyuki*; Hirota, Katsuya*; Ishizaki, Kohei*; Kimura, Atsushi; Kitaguchi, Masaaki*; Niinomi, Yudai*; Okudaira, Takuya*; et al.

Physical Review C, 105(5), p.054615_1 - 054615_5, 2022/05

https://doi.org/10.1103/PhysRevC.105.054615

no abstracts in English

Improvement of HI concentration performance for hydrogen production iodine-sulfur process using crosslinked cation-exchange membrane

Tanaka, Nobuyuki; Sawada, Shinichi*; Yamaki, Tetsuya*; Kodaira, Takahide*; Kimura, Takehiro*; Nomura, Mikihiro*

Chemical Engineering Science, 237, p.116575_1 - 116575_11, 2021/06

https://doi.org/10.1016/j.ces.2021.116575

We have been developing the ion exchange membranes by a radiation grafted polymerization method to improve HI concentration performance for Electro-electrodialysis (EED) in the thermochemical water-splitting hydrogen production iodine-sulfur process. In this work, the crosslinking structures were introduced to the ion exchange membranes. The proton conductivity (), transport number (t), and water permeation factor () of these crosslinked ion exchange membranes were measured and the effect of crosslinks to these performance indexes were investigated. The introduction of crosslinks was found to improve the selectivity of H and water transport (increase of t and decrease of ), although the somewhat decreased. The EED model that we established to discuss the permeation mechanism of EED system was used to theoretically analyze the effect of crosslink on the performance indexes. Based on this analysis of measurement results, the introduction of the crosslink was found to little affect the absorbed amount of HIx solution and H diffusion coefficient in the tested membranes, whereas it could lead to decrease I diffusion coefficient. The results of and t could reflect these effects. In addition, we found the fact that crosslink can inhibit the swelling due to the absorption of the HIx solution. As a result, the value decreased owing to the introduction of crosslink.

Quasifree neutron knockout reaction reveals a small -Orbital component in the Borromean nucleus B

Yang, Z. H.*; Kubota, Yuki*; Corsi, A.*; Yoshida, Kazuki; Sun, X.-X.*; Li, J. G.*; Kimura, Masaaki*; Michel, N.*; Ogata, Kazuyuki*; Yuan, C. X.*; et al.

Physical Review Letters, 126(8), p.082501_1 - 082501_8, 2021/02

AA2020-0819.pdf:1.29MB

https://doi.org/10.1103/PhysRevLett.126.082501

A quasifree (,) experiment was performed to study the structure of the Borromean nucleus B, which had long been considered to have a neutron halo. By analyzing the momentum distributions and exclusive cross sections, we obtained the spectroscopic factors for and orbitals, and a surprisingly small percentage of 9(2)% was determined for . Our finding of such a small component and the halo features reported in prior experiments can be explained by the deformed relativistic Hartree-Bogoliubov theory in continuum, revealing a definite but not dominant neutron halo in B. The present work gives the smallest - or -orbital component among known nuclei exhibiting halo features and implies that the dominant occupation of or orbitals is not a prerequisite for the occurrence of a neutron halo.

Overvoltage reduction in membrane Bunsen reaction for hydrogen production by using a radiation-grafted cation exchange membrane and porous Au anode

Sawada, Shinichi*; Kimura, Takehiro*; Nishijima, Haruyuki*; Kodaira, Takahide*; Tanaka, Nobuyuki; Kubo, Shinji; Imabayashi, Shinichiro*; Nomura, Mikihiro*; Yamaki, Tetsuya*

International Journal of Hydrogen Energy, 45(27), p.13814 - 13820, 2020/05

https://doi.org/10.1016/j.ijhydene.2020.02.229

An electrochemical membrane Bunsen reaction using a cation exchange membrane (CEM) is a key to achieving an iodine-sulfur (IS) thermochemical water splitting process for mass-production of hydrogen. In this study, we prepared both the radiation-grafted CEM with a high ion exchange capacity (IEC) and the highly-porous Au-electroplated anode, and then used them for the membrane Bunsen reaction to reduce the cell overvoltage. The high-IEC grafted CEM exhibited low resistivity for proton transport, while the porous Au anode had a large effective surface area for anodic SO oxidation reaction. As a result, the cell overvoltage for the membrane Bunsen reaction was significantly reduced to 0.21 V at 200 mA/cm, which was only one-third of that of the previous test using the commercial CEM and non-porous anode. From the analysis of the current-voltage characteristics, employment of the grafted CEM was found to be more effective for the overvoltage reduction compared to the porous Au anode.

Propagation of U(V)-reduction in the presence of U(IV) aggregate in a weakly acidic solution

Kitatsuji, Yoshihiro; Otobe, Haruyoshi; Kimura, Takaumi; Kihara, Sorin*

Electrochimica Acta, 141, p.6 - 12, 2014/09

https://doi.org/10.1016/j.electacta.2014.07.012

Reduction processes of U(VI) in weakly acidic solutions were investigated based on electrochemical and spectrophotometric measurements. A reversible one-electron reduction of U(VI) to U(V) and a further irreversible reduction of U(V) were observed voltammetrically at a gold microdisk electrode in solutions of pH from 2.0 to 3.5. Aggregates of U(IV) were formed as a deposit on the electrode and a colloid in the bulk solution, when the electrolysis was carried out at a gold gauze electrode, even though the potential applied was that available for the first one-electron reduction wave of U(VI) observed. It was elucidated that the aggregate was produced by the combination of the one-electron reduction to U(V) and the disproportionation of U(V) producing U(IV) and U(VI). The aggregate enhanced the rate of the disproportionation of U(V), and hence the reduction current of U(VI) increased abruptly when a definite amount of aggregate was formed on the electrode, in the solution, or both.

Plan and strategy for ITER blanket testing in Japan

Enoeda, Mikio; Akiba, Masato; Tanaka, Satoru*; Shimizu, Akihiko*; Hasegawa, Akira*; Konishi, Satoshi*; Kimura, Akihiko*; Koyama, Akira*; Sagara, Akio*; Muroga, Takeo*

Fusion Science and Technology, 47(4), p.1023 - 1030, 2005/05

https://doi.org/10.13182/FST05-A822

The Fusion Council of Japan has established the long-term research and development program of the blanket in 1999. In the program, the solid breeder blanket was selected as the primary candidate blanket of the fusion power demonstration plant in Japan. In the program, Japan Atomic Energy Research Institute (JAERI) has been nominated as a leading institute of the development of solid breeder blankets, in collaboration with universities, for the near term power demonstration plant, while, universities including National Institute for Fusion Science (NIFS) are assigned mainly to develop advanced blankets for longer term power plant development. In the long term research and development program, ITER blanket module testing is identified as the most important milestone, by which integrity of candidate blanket concepts and structures are evaluated. In Japan, universities, NIFS and JAERI cover a variety of types of blanket development. This paper presents a plan and strategy for ITER blanket module testing in Japan.

Research and development on the Ion Cyclotron Range of Frequency heating system in JT-60U

Moriyama, Shinichi; Fujii, Tsuneyuki; Kimura, Haruyuki; Anno, Katsuto; Yokokura, Kenji; Shinozaki, Shinichi; Terakado, Masayuki; Hiranai, Shinichi; Saigusa, Mikio*

Fusion Science and Technology (JT-60 Special Issue), 42(2-3), p.467 - 481, 2002/09

https://doi.org/10.13182/FST02-A241

no abstracts in English

Characteristics of Alfvn eigenmodes, burst modes and chirping modes in the Alfvn frequency range driven by negative ion based neutral beam injection in JT-60U

Kusama, Yoshinori; Kramer, G. J.; Kimura, Haruyuki; Saigusa, Mikio*; Ozeki, Takahisa; Tobita, Kenji; Oikawa, Toshihiro; Shinohara, Koji; Kondoh, Takashi; Moriyama, Shinichi; et al.

Nuclear Fusion, 39(11Y), p.1837 - 1843, 1999/11

https://doi.org/10.1088/0029-5515/39/11Y/324

no abstracts in English

Production and confinement characteristics of ICRF-accelerated energetic ions in JT-60U negative-shear plasmas

Kusama, Yoshinori; Kimura, Haruyuki; Nemoto, Masahiro; Hamamatsu, Kiyotaka; Tobita, Kenji; Oikawa, Toshihiro; Afanassiev, V. I.*; Morioka, Atsuhiko; Fujita, Takaaki; Koide, Yoshihiko; et al.

Plasma Physics and Controlled Fusion, 41(5), p.625 - 643, 1999/00

https://doi.org/10.1088/0741-3335/41/5/305

no abstracts in English