Tritium absorption of co-deposited carbon films

Nobuta, Yuji*; Yamauchi, Yuji*; Hino, Tomoaki*; Akamaru, Satoshi*; Hatano, Yuji*; Matsuyama, Masao*; Suzuki, Satoshi; Akiba, Masato

Fusion Engineering and Design, 87(7-8), p.1070 - 1073, 2012/08

https://doi.org/10.1016/j.fusengdes.2012.02.080

Deuterium ion irradiation for tritium breeding material and evaluation for tritium inventories in test blanket module and blanket of a demonstration reactor

Hino, Tomoaki*; Shibata, Hironobu*; Yamauchi, Yuji*; Nobuta, Yuji*; Suzuki, Satoshi; Akiba, Masato

Journal of Nuclear Materials, 417(1-3), p.713 - 717, 2011/10

https://doi.org/10.1016/j.jnucmat.2010.12.124

Hydrogen isotope retention in the outboard first wall tiles of JT-60U

Yoshida, Masafumi; Tanabe, Tetsuo*; Nobuta, Yuji*; Hayashi, Takao; Masaki, Kei; Sato, Masayasu

Journal of Nuclear Materials, 390-391, p.635 - 638, 2009/06

https://doi.org/10.1016/j.jnucmat.2009.01.177

We have investigated hydrogen isotopes retention in the outboard first wall tiles of JT-60U by means of TDS, SIMS and SEM. The outboard first wall tiles of JT-60U are mostly eroded. The total retention (H+D) normalized by a unit area and integrated NBI time in the eroded first wall tiles and the eroded divertor tiles were nearly the same, in spite of the lower temperature of the first wall. Differently from divertor tiles, in which H retention was dominated owing to HH discharges preformed after DD discharges, deuterium is dominated in hydrogen isotopes retention and penetrates deeper from the surface. This is attributed to injection of high energy D and difficulty of isotopic replacement owing to their lower temperature. The integrated amount over the whole surface could be appreciably large. This type of hydrogen retention could be also possible for the metallic wall.

Localized tungsten deposition in divertor region in JT-60U

Ueda, Yoshio*; Fukumoto, Masakatsu*; Watanabe, Jun*; Otsuka, Yusuke*; Arai, Takashi; Asakura, Nobuyuki; Nobuta, Yuji*; Sato, Masayasu; Nakano, Tomohide; Yagyu, Junichi; et al.

Proceedings of 22nd IAEA Fusion Energy Conference (FEC 2008) (CD-ROM), 8 Pages, 2008/10

http://www-naweb.iaea.org/napc/physics/FEC/FEC2008/html/node161.htm#37485

Deposition profiles of tungsten released from the outer divertor were studied in JT-60U. A neutron activation method was used for the first time to accurately measure deposited tungsten. Surface density of tungsten in the thick carbon deposition layer can be measured by this method. Tungsten was mainly deposited on the inner divertor (around inner strike points) and on the outer wing of the dome. Toroidal distribution of the W deposition was significantly localized near the tungsten released position, while other metallic impurities such as Fe, Cr, Ni were distributed more uniformly. These data indicate that inward drift in the divertor region played a significant role in tungsten transport in JT-60U.

Deposition and transport of C from methane injection into outer divertor plasma in JT-60U

Nobuta, Yuji; Masaki, Kei; Arai, Takashi; Sakasai, Akira; Miya, Naoyuki; Tanabe, Tetsuo*

Europhysics Conference Abstracts (CD-ROM), 31F, 4 Pages, 2007/00

http://epsppd.epfl.ch/Warsaw/pdf/P1_024.pdf

no abstracts in English

Kinetics study of deuterium desorption process in high purity boron film

Nakahata, Toshihiko*; Oya, Yasuhisa*; Yoshikawa, Akira*; Suda, Taichi*; Oyaizu, Makoto*; Ashikawa, Naoko*; Nishimura, Kiyohiko*; Yagyu, Junichi; Kizu, Kaname; Nobuta, Yuji; et al.

no journal, , 

no abstracts in English

Redeposition distribution of tungsten eroded from the tungsten coated divertor tiles in JT-60U

Fukumoto, Masakatsu*; Otsuka, Yusuke*; Ueda, Yoshio*; Tanabe, Tetsuo*; Sakasai, Akira; Masaki, Kei; Arai, Takashi; Yagyu, Junichi; Nobuta, Yuji; Kubo, Hirotaka; et al.

no journal, , 

no abstracts in English

Deuterium retention and desorption behaviors of F82H exposed to low energy hydrogen plasma

Suzuki, Satoshi; Ito, Tatsuya*; Nobuta, Yuji*; Yamauchi, Yuji*; Hino, Tomoaki*; Ezato, Koichiro; Yokoyama, Kenji; Akiba, Masato

no journal, , 

A reduced activation ferritic-maternstic steel, F82H, is one of candidate structural materials for the first wall of fusion machines. For F82H, retention and desorption behavior of F82H has not been clarified though such behavior is considered to be significant from the plasma density control and safety points of view. In this study, F82H samples were irradiated by hydrogen ion in JAEA. In addition, these samples with surface defects were also irradiated by deuterium ion to investigate the retention and the desorption behavior based on its surface defects. As a result, while the amount of the deuterium retention has not been changed at a holding temperature below 550 K, it is significantly decreased at a holding temperature over 770 K.