Fusion Science and Technology / Volume 60 / Number 4 / November 2011 / Pages 1548-1551
Interaction with Materials / Proceedings of the Ninth International Conference on Tritium Science and Technology (Part 2)
Areal mass densities of carbon dust collected in the baffle and divertor regions of JT-60U were investigated. On the plasma-facing surface, large areal density of 610 mg/m2 is found at the upper tile of the inner divertor, which is much larger than other areas due to the soft deposition. On the other hand, as for the plasma-shadowed area, largest areal density of 5,100 mg/m2 was found underneath the dome structure. The total dust weights at the plasma-facing surface and the shadowed areas were estimated to be 1.3 g and 22.2 g, respectively, assuming the toroidal symmetry. Count-based size distributions were also investigated. The average dust size of the main population is less than 20 m for both the plasma-facing surface and the shadowed area.