Measurement of Dust Quantity and Distribution Collected from JT-60U

AbstractAreal 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/m2is 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/m2was 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 μm for both the plasma-facing surface and the shadowed area.