Fusion Science and Technology / Volume 62 / Number 1 / July 2012 / Pages 66-70
Hydrogen/Tritium Behavior / Proceedings of the Fifteenth International Conference on Fusion Reactor Materials, Part A: Fusion Technology
The removal of deuterium retained in boron, titanium, and titanium oxide films by neon glow discharge was investigated. The films were exposed to deuterium glow plasma to retain the deuterium and subsequently exposed to neon glow plasma. The temperature of the exposures was room temperature. The residual deuterium was estimated by thermal desorption spectroscopy. The removal ratio of deuterium by neon glow discharge largely depended on the material. Namely, the ratios for boron, titanium, or titanium oxide were 14%, 2%, or 40%, respectively. The ratios for the boron and the titanium oxide roughly agreed with the estimation from SRIM code calculations, while the ratio for the titanium did not agree with the estimation. These results suggest that the reduction of the deuterium retention is owing to the etching and the ion impact desorption of neon ions in the cases of boron and titanium oxide, and the prompt re-trapping of deuterium by titanium atoms might occur in the case of titanium. The comparison between titanium and titanium oxide clearly shows that the removal effect by glow discharge largely depended on the surface conditions, such as oxygen impurity.