Rotation of complex ions with ninefold hydrogen coordination studied by quasielastic neutron scattering and first-principles molecular dynamics calculations

Omasa, Yoshinori*; Takagi, Shigeyuki*; Toshima, Kento*; Yokoyama, Kaito*; Endo, Wataru*; Orimo, Shinichi*; Saito, Hiroyuki*; Yamada, Takeshi*; Kawakita, Yukinobu; Ikeda, Kazutaka*; et al.

Physical Review Research (Internet), 4(3), p.033215_1 - 033215_9, 2022/09

https://doi.org/10.1103/PhysRevResearch.4.033215

Origin of degradation in the reversible hydrogen storage capacity of VTi alloys from the atomic pair distribution function analysis

Kim, H.*; Sakaki, Koji*; Ogawa, Hiroshi*; Nakamura, Yumiko*; Nakamura, Jin*; Akiba, Etsuo*; Machida, Akihiko; Watanuki, Tetsu; Proffen, T.*

Journal of Physical Chemistry C, 117(50), p.26543 - 26550, 2013/12

https://doi.org/10.1021/jp408766r

Reduction in reversible hydrogen storage capacity with increasing hydrogenation and dehydrogenation cycle number is observed in numerous hydrogen storage materials, but the mechanism behind this unfavorable change has not been elucidated yet. In this study, we have investigated the development of structural defects or disorders in VTiH, = 0, 0.2, and 0.5, during the first 15 hydrogen absorption and desorption cycles using the atomic pair distribution function (PDF) analysis of synchrotron X-ray total scattering data to find out the possible structural origin of the poor cyclic stability of VTi alloys.

Azimuthal correlations of electrons from heavy-flavor decay with hadrons in and Au+Au collisions at = 200 GeV

Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Aramaki, Y.*; et al.

Physical Review C, 83(4), p.044912_1 - 044912_16, 2011/04

https://doi.org/10.1103/PhysRevC.83.044912

Measurements of electrons from the decay of open-heavy-flavor mesons have shown that the yields are suppressed in Au+Au collisions compared to expectations from binary-scaled collisions. Here we extend these studies to two particle correlations where one particle is an electron from the decay of a heavy flavor meson and the other is a charged hadron from either the decay of the heavy meson or from jet fragmentation. These measurements provide more detailed information about the interaction between heavy quarks and the quark-gluon matter. We find the away-side-jet shape and yield to be modified in Au+Au collisions compared to collisions.

Achievements in the development of the water cooled solid breeder test blanket module of Japan to the milestones for installation in ITER

Tsuru, Daigo; Tanigawa, Hisashi; Hirose, Takanori; Mori, Kensuke*; Seki, Yohji; Enoeda, Mikio; Ezato, Koichiro; Suzuki, Satoshi; Nishi, Hiroshi; Akiba, Masato

Nuclear Fusion, 49(6), p.065024_1 - 065024_8, 2009/06

https://doi.org/10.1088/0029-5515/49/6/065024

Research and development on Water-Cooled Solid Breeder Test Blanket Module in JAEA

Enoeda, Mikio; Tanigawa, Hisashi; Tsuru, Daigo; Hirose, Takanori; Ezato, Koichiro; Yokoyama, Kenji; Dairaku, Masayuki; Seki, Yohji; Suzuki, Satoshi; Mori, Kensuke*; et al.

Proceedings of 16th Pacific Basin Nuclear Conference (PBNC-16) (CD-ROM), 6 Pages, 2008/10

Studies on tritium breeding ratio for solid breeder blanket cooled by pressurized water through nuclear and thermal analyses

Seki, Yohji; Tanigawa, Hisashi; Tsuru, Daigo; Enoeda, Mikio; Akiba, Masato; Ezato, Koichiro; Tanzawa, Sadamitsu; Nishi, Hiroshi; Hirose, Takanori; Homma, Takashi; et al.

JAEA-Technology 2007-067, 34 Pages, 2008/01

JAEA-Technology-2007-067.pdf:14.41MB
JAEA-Technology-2007-067(errata).pdf:0.08MB

This report is result of one-dimensional nuclear and thermal analyses on Test Blanket Module (TBM) for ITER emphasizing on optimized layer structures of a ceramic tritium breeder () and a beryllium neutron multiplier . Taking into account increment of Tritium Breeding Ratio (TBR), the radial widths of the breeder and multiplier layers are optimized. The main results of our study are as follows: (1) In multilayered structures of pebble beds, the peak of the TBR exists within the range of the volume ratio (2) In the case of the single packing, the R stayed in the range of by setting the two layers of Be behind a layer of . This database of TBR for optimized layer structures contributes to the estimation of TBR at the design stage of the TBM and demonstration blanket.

Test strategy and development achievements of ITER solid breeder test blanket modules in Japan

Enoeda, Mikio; Hirose, Takanori; Tanigawa, Hisashi; Tsuru, Daigo; Suzuki, Satoshi; Ezato, Koichiro; Hatano, Toshihisa; Nomoto, Yasunobu; Nishi, Hiroshi; Homma, Takashi; et al.

Proceedings of 21st IAEA Fusion Energy Conference (FEC 2006) (CD-ROM), 8 Pages, 2007/03

http://www-naweb.iaea.org/napc/physics/FEC/FEC2006/html/node303.htm#59769

This paper presents progresses of the test strategy development, design and supporting R&Ds of solid breeder Test Blanket Modules (TBMs) in Japan. Japan is proposing to test its unique designs of Water Cooled Solid Breeder (WCSB) TBM and Helium Cooled Solid Breeder (HCSB) TBM from the beginning of the ITER operation. As for the design work, structure design showed steady progress and clarified detailed structure taking into account the fabrication procedure. As for supporting R&Ds, the corrosion characteristics of the structural material by high temperature and pressure water was clarified as one of critical structure integrity issues. Also, important design data of the breeder pebble bed has been clarfied. Along with the development progress, the test strategy has been investigated to obtain the most effective results of TBM test program.

Overview of the national centralized tokamak programme

Kikuchi, Mitsuru; Tamai, Hiroshi; Matsukawa, Makoto; Fujita, Takaaki; Takase, Yuichi*; Sakurai, Shinji; Kizu, Kaname; Tsuchiya, Katsuhiko; Kurita, Genichi; Morioka, Atsuhiko; et al.

Nuclear Fusion, 46(3), p.S29 - S38, 2006/03

https://doi.org/10.1088/0029-5515/46/3/S05

The National Centralized Tokamak (NCT) facility program is a domestic research program for advanced tokamak research to succeed JT-60U incorporating Japanese university accomplishments. The mission of NCT is to establish high beta steady-state operation for DEMO and to contribute to ITER. The machine flexibility and mobility is pursued in aspect ratio and shape controllability, feedback control of resistive wall modes, wide current and pressure profile control capability for the demonstration of the high-b steady state.

Design study of national centralized tokamak facility for the demonstration of steady state high- plasma operation

Tamai, Hiroshi; Akiba, Masato; Azechi, Hiroshi*; Fujita, Takaaki; Hamamatsu, Kiyotaka; Hashizume, Hidetoshi*; Hayashi, Nobuhiko; Horiike, Hiroshi*; Hosogane, Nobuyuki; Ichimura, Makoto*; et al.

Nuclear Fusion, 45(12), p.1676 - 1683, 2005/12

https://doi.org/10.1088/0029-5515/45/12/023

Design studies are shown on the National Centralized Tokamak facility. The machine design is carried out to investigate the capability for the flexibility in aspect ratio and shape controllability for the demonstration of the high-beta steady state operation with nation-wide collaboration, in parallel with ITER towards DEMO. Two designs are proposed and assessed with respect to the physics requirements such as confinement, stability, current drive, divertor, and energetic particle confinement. The operation range in the aspect ratio and the plasma shape is widely enhanced in consistent with the sufficient divertor pumping. Evaluations of the plasma performance towards the determination of machine design are presented.

Development of fusion nuclear technologies at Japan Atomic Energy Research Institute

Seki, Masahiro; Yamanishi, Toshihiko; Shu, Wataru; Nishi, Masataka; Hatano, Toshihisa; Akiba, Masato; Takeuchi, Hiroshi; Nakamura, Kazuyuki; Sugimoto, Masayoshi; Shiba, Kiyoyuki; et al.

Fusion Science and Technology, 42(1), p.50 - 61, 2002/07

https://doi.org/10.13182/FST02-A212

Latest status on development of long-term fusion nuclear technologies at JAERI is overviewed. A tritium processing system for the ITER and DEMO reactors was designed and basic technologies for each component of this system was demonstrated successfully by an operation of the integrated system for one month. An ultra-violet laser with a wave length of 193 nm was found quite effective for removing tritium from in-vessel components of D-T fusion reactors. Blanket technologies have been developed for the Test Blanket Module of the ITER and for advanced blankets for DEMO reactors. This blanket is composed of LiTiO breeder pebbles and neutron multiplier Be pebbles, contained in a box structures made of a reduced activation ferritic steel F82H. Mechanical properties of F82H under neutron irradiation up to 50 dpa were obtained in a temperature range from 200 to 500C. Design of the International Fusion Materials Irradiation Facility (IFMIF) has been developed so as to obtain engineering data for candidate materials for DEMO reactors, under neutron irradiation up to 100-200 dpa.