[Table of Contents]

Plasma and Fusion Research

Volume 7, 2405091 (2012)

Regular Articles

Tritium Retention on Stainless Steel Surface Exposed to Plasmas in LHD
Masao MATSUYAMA, Jyunpei SAIKAWA, Shinsuke ABE, Kiyohiko NISHIMURA1), Naoko ASHIKAWA1), Yasuhisa OYA2), Kenji OKUNO2), Tomoaki HINO3) and Akio SAGARA1)
Hydrogen Isotope Research Center, University of Toyama, 3190 Gofuku, Toyama 930-8555, Japan
1)
National Institute for Fusion Science, 322-6 Oroshi-cho, 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 29 December 2011 / Accepted 27 April 2012 / Published 26 July 2012)

Abstract

Tritium retention of samples exposed to plasmas in the Large Helical Device (LHD) during each campaign in 12th, 13th and 14th cycles has been studied. Small sample plates made of stainless steel type 316L were fixed in advance at four different walls in LHD: location of a sample plate was 1.5U, 5.5U, 6.5L and 9.5L. After plasma exposure in each cycle, these samples were exposed to tritium gas at a temperature of 300 or 623 K. Retention behavior of tritium in surface layers of each sample was mainly examined using β-ray-induced X-ray spectrometry (BIXS) and X-ray photoelectron spectroscopy (XPS). The energy spectra observed by BIXS and XPS showed the depositions of boron, carbon, titanium, chromium, iron, nickel and molybdenum with oxygen. Tritium retention of the samples exposed to plasma increased than that of a bare SS316L sample, although it was largely different in the location of a sample. When the samples were exposed to tritium gas at 300 K, the order of magnitude of tritium retention was as follows: 9.5L≫5.5U>6.5L>1.5U for 12th cycle, 6.5L>9.5>1.5U>5.5U for 13th cycle, and 6.5L>1.5U∼5.5U>9.5L for 14th cycle.

Keywords

tritium, retention, plasma exposure, BIXS, stainless steel, plasma-facing material

DOI: 10.1585/pfr.7.2405091

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References

  • [1] A. Iiyoshi, A. Komori et al., Nucl. Fusion 39, 1245 (1999).
  • [2] T. Hino, Y. Nobuta et al., Fusion Eng. Des. 82, 1621 (2007).
  • [3] M. Matsuyama et al., J. Nucl. Mater. 290-293, 437 (2001).
  • [4] M. Matsuyama et al., J. Nucl. Mater. 417, 900 (2011).
  • [5] M. Matsuyama et al., Fusion Sci. Technol. 41, 505 (2002).

This paper may be cited as follows:

Masao MATSUYAMA, Jyunpei SAIKAWA, Shinsuke ABE, Kiyohiko NISHIMURA, Naoko ASHIKAWA, Yasuhisa OYA, Kenji OKUNO, Tomoaki HINO and Akio SAGARA, Plasma Fusion Res. 7, 2405091 (2012).