Simulation Analysis of the Carbon Deposition Profile on Directional Material Probes in the Large Helical Device Using the ERO2.0 Code

The carbon deposition profile on a Directional Material Probe (DMP) installed in the inboard side of the torus in the Large Helical Device (LHD) is investigated using the ERO2.0 code. The experimental result of the carbon deposition profile with short and wide shadows (lower deposition density areas) on the DMP is reasonably explained by the carbons sputtered from the carbon divertor plates installed in the inboard side. The simulation proves that the short and wide shadows are produced by carbons sputtered from the right and left divertor plate arrays, respectively. The experimental carbon deposition profile accumulated in the previous experimental campaign (FY2010) was successfully reproduced by the simulation, which provides detailed understanding of material (carbon) migration in the divertor region in the LHD.