FULL TEXT (PDF, 254KB)
T. Hino, T. Hirata, N. Ashikawa, S. Masusaki, Y. Yamauchi, Y. Nobuta, N. Ohyabu, A. Sagara, N. Noda, A. Komori, O. Motojima and LHD Experimental Group
Hydrogen Concentration of Co-deposited Carbon Films Produced in the Vicinity of Local Island Divertor in Large Helical Device
Date of publication:
21 IAEA Fusion Energy Conference, EX/P4-8
It is quite important to evaluate hydrogen concentration of co-deposited carbon film/dust to estimate in-vessel tritium inventory in ITER. The co-deposited carbon films were prepared at the wall of pumping duct in Local Island Divertor experiments of LHD. 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 by hydrogen ion irradiation to graphite. The crystal structure of the co-deposited carbon film observed by Raman spectroscopy showed very unique structure (polymeric a-C:H), which is well consistent with the high hydrogen concentration. The accumulation of in-vessel tritium inventory is also discussed.
List of NIFS Report (2008)Return toContents Page Return toNIFS Homepage