カーボンダストの重水素保持特性 Deuterium Retention of Carbon Dust
In a nuclear fusion device, plasma facing materials (PFMs) such as graphite are bombarded by extremely high heat and particle fluxes during an abnormal discharge called as disruption. As a result of the disruption, the PFMs are eroded and deposited on the wall. In the case of graphite plasma facing material, carbon dusts are produced. Flaky carbon dust was produced from isotropic graphite by electron beam evaporation. The absorption properties of deuterium in carbon dust were investigated by changing an absorption temperature (773-1173 K), time (10 min-24 hr) and deuterium gas pressure (1-100 Pa). The amount of adsorbed deuterium was evaluated by using thermal desorption spectroscopy. Deuterium was desorbed from the carbon dust at the temperature higher than 873 K in form of HD and D<SUB>2</SUB>. At the absorption temperature of 973 K and the pressure of 100 Pa, the amount of deuterium absorbed in the dust saturated within 5 hr. This saturation level was one or two orders of magnitude larger than that of isotropic graphite. The heat of solution for deuterium was 0.27 eV which was almost the same as that of isotropic graphite.
真空 43(3), 377-380, 2000-03-20
The Vacuum Society of Japan