[Table of Contents]

Plasma and Fusion Research

Volume 9, 3405135 (2014)

Regular Articles

Tritium Retention on the Surface of Stainless Steel Samples Fixed on the Plasma-Facing Wall in LHD
Masao MATSUYAMA, Shinsuke ABE, Kiyohiko NISHIMURA1), Naoko ASHIKAWA1), Yasuhisa OYA2), Kenji OKUNO2), Yuji YAMAUCHI3), Yuji NOBUTA3) and Akio SAGARA1)
Hydrogen Iosotope Research Center, University of Toyama, 3190 Gofuku, Toyama 930-8555, Japan
1)
National Institute for Fusion Science, Toki 509-5292, Japan
2)
Radiochemistry Research Laboratory, Shizuoka University, Shizuoka 422-8529, Japan
3)
Laboratory of Plasma Physics and Engineering, Hokkaido University, Sapporo 060-8628, Japan
(Received 19 November 2013 / Accepted 23 July 2014 / Published 17 September 2014)

Abstract

Effects of pre-heating for retention and distribution of tritium have been studied using samples fixed on the wall of the Large Helical Device during a plasma campaign. The samples were fixed at four different locations. The plasma-facing surface of the samples was covered with deposition layers of different thickness in each sample. Retention behavior in deposition layers was observed using β-ray-induced X-ray spectrometry and imaging plate technique. Pre-heating of the samples in vacuum was changed in a temperature range from 300 to 623 K, and subsequent tritium exposure was carried out at 300 K in every runs. Non-uniformity of tritium distribution clearly appeared even in the as-received samples which was not pre-heated. It is considered, therefore, that non-uniform adsorption sites of tritium have been produced during a formation process of deposition layers. In addition, it was seen that the amount of tritium retention increased with an increase in the pre-heating temperature, indicating that adsorption sites of tritium were newly formed in the deposition layers by heating in vacuum.

Keywords

tritium retention, plasma-facing material, deposition layer, β-ray-induced X-ray spectrometry

DOI: 10.1585/pfr.9.3405135

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References

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  • [2] M. Matsuyama et al., Plasma Fusion Res. 7, 2405091 (2012).
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This paper may be cited as follows:

Masao MATSUYAMA, Shinsuke ABE, Kiyohiko NISHIMURA, Naoko ASHIKAWA, Yasuhisa OYA, Kenji OKUNO, Yuji YAMAUCHI, Yuji NOBUTA and Akio SAGARA, Plasma Fusion Res. 9, 3405135 (2014).