Hydrogen Concentration of Co-Deposited Carbon Films Produced in the Vicinity of Local Island Divertor in LHD
Hydrogen Concentration of Co-Deposited Carbon Films Produced in the Vicinity of Local Island Divertor in LHD作者机构:Laboratory of Plasma Physics and Engineering Hokkaido University Hokkaido 060-8628 Japan National Institute for Fusion Science Toki-shi 509-5202 Japan
出 版 物:《Journal of Energy and Power Engineering》 (能源与动力工程(美国大卫英文))
年 卷 期:2011年第5卷第5期
页 面:428-433页
学科分类:0808[工学-电气工程] 080803[工学-高电压与绝缘技术] 07[理学] 08[工学] 070204[理学-等离子体物理] 0702[理学-物理学]
主 题:In-vessel tritium inventory ITER LHD co-deposited carbon film hydrogen concentration crystal structure.
摘 要:In international thermonuclear experimental reactor (ITER), one of major concerns is an in-vessel tritium inventory from a point of safety. It is believed that the carbon-tritium co-deposited film produced by the erosion of carbon diverter walls has a high tritium concentration. However, no systematic evaluation for the tritium concentration has been conducted yet. In the present study, the carbon-hydrogen co-deposited films were prepared at the wall of pumping duct in Local Island Divertor experiments of LHD, in order to evaluate the tritium concentration of the co-deposited films produced in ITER. The hydrogen concentration was obtained by measuring the amount of retained hydrogen in the film and the mass density of the film. The hydrogen concentration of the co-deposited carbon film at the wall not facing to the plasma with a low temperature was extremely high, 1.3 in the atomic ratio of H/C. This value is triple times higher than the previous value obtained so far. The crystal structure of the co-deposited carbon film observed by Raman spectroscopy showed very unique structure (polymeric aC:H), which is well consistent with the high hydrogen concentration. The present study suggests that the tritium concentration of the co-deposited film in ITER depends on the wall position and becomes quite high as high as T/C-0.65. The results obtained contribute to evaluate the in-vessel tritium inventory owing to the co-deposited carbon films.