Abstract
Retention of D in neutron-irradiated W and desorption were examined after plasma exposure at 773 K. Deuterium was accumulated at a relatively high concentration up to a large depth of 50-100 μm due to the trapping effects of defects uniformly induced in the bulk. A significant D release in a vacuum continued to temperatures P1173 K because of the small effective diffusion coefficient and the long diffusion distance. Exposure of ion-irradiated W to D2 gas showed a clear correlation between concentrations of trapped and solute D as determined by the trapping-detrapping equilibrium. These observations indicated that the accumulation of tritium in high concentrations is possible even at high temperatures if the concentration of solute tritium is high, and baking at moderate temperatures is ineffective for removal of tritium deeply penetrating into the bulk. Nevertheless, clear enhancement of D release was observed under the presence of solute H.
Original language | English |
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Pages (from-to) | S114-S119 |
Journal | Journal of Nuclear Materials |
Volume | 438 |
Issue number | SUPPL |
DOIs | |
State | Published - 2013 |
Funding
This work was supported by the Japan-US joint research project TITAN, Kakenhi on Priority Areas, 476, Tritium for Fusion, from MEXT, Japan and the Collaboration Research Programs of National Institute of Fusion Science, Japan (NIFS10KUMR004 and NIFS11KEMF018). The authors thank to Dr. T. Yamanishi and Dr. K. Isobe in Japan Atomic Energy Agency for the supply of recrystallized and ITER-grade W specimens.