2004 Volume 47 Issue 3 Pages 239-242
Hydrogen retention in carbon dust produced by hydrogen discharges in JT-60 was investigated to estimate the tritium inventory for the next generation of fusion reactors such as ITER. Several types of dust-like pieces were collected from the vacuum vessel, flake-like carbon dust, graphite, and metal pieces. The amount of retained hydrogen in the flake-like carbon dust was two orders of magnitude larger than that of the other samples. The hydrogen concentration of the flake-like carbon dust was less than 0.04 in the atomic ratio of H/C. This value is one order of magnitude smaller than that of carbon dust produced in the large tokamak, JET. This difference can be explained by the wall temperature in JT-60 being higher than in JET. The surface morphology and atomic compositions were also examined for characterization of the collected samples.
