Retention of Hydrogen Isotopes in Divertor Tiles Used in JT-60U

Journal Article · Fri Jul 15 00:00:00 EDT 2005 · Fusion Science and Technology

OSTI ID:20854208

Hirohata, Y ^[1]; Shibahara, T ^[2]; Tanabe, T ^[2]; Oya, Y ^[3]; Arai, T ^[4]; Gotoh, Y ^[4]; Masaki, K ^[4]; Yagyu, J ^[4]; Oyaidzu, M ^[5]; Okuno, K ^[5]; Nishikawa, M ^[6]; Miya, N ^[4]

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1. Hokkaido University (Japan)
2. Nagoya University (Japan)
3. University of Tokyo (Japan)
4. Japan Atomic Energy Research Institute (Japan)
5. Shizuoka University (Japan)
6. Kyusyu University (Japan)

Retention characteristics of deuterium and hydrogen retained in graphite tiles placed in the divertor region of JT-60U were investigated by thermal desorption spectroscopy (TDS). The deuterium retained in the near surface of all graphite tiles was mostly replaced by hydrogen due to exposure to hydrogen plasma at the final stage operations, resulting in main deuterium retention in the deeper region. The dominant species desorbed from the divertor tiles were H{sub 2}, HD, D{sub 2} and CH{sub 4}. The smallest retention of hydrogen isotopes (H+D) was observed in the outer divertor tile which was eroded with maximum of 20 {mu}m depth. The amount of H+D retained in the inner divertor tiles covered by the re-deposited layers increased with the thickness of the re-deposited layers. Hydrogen isotopes concentration ((H+D)/C) in the re-deposited layers was {approx}0.02, which was much smaller than those observed in JET and other devices.

• OSTI ID: 20854208
• Journal Information: Fusion Science and Technology, Vol. 48, Issue 1; Other Information: Copyright (c) 2006 American Nuclear Society (ANS), United States, All rights reserved. http://epubs.ans.org/; Country of input: International Atomic Energy Agency (IAEA); ISSN 1536-1055
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
DESORPTION
DEUTERIUM
DIVERTORS
GRAPHITE
HYDROGEN
JET TOKAMAK
JT-60U TOKAMAK
LAYERS
METHANE
PLASMA
RETENTION
SPECTROSCOPY