Error Estimation for Plasma Power Deposition in Tokamak First Wall Designs

Accurate computation of power deposition is expected to be critical for the successful design of plasma-facing components (PFCs) in reactor-scale magnetic confinement devices. The work provides analysis and model computations to help explain the high levels of accuracy obtainable using relatively coarse meshing of PFCs to treat cases with sharp-edged shadowing of one PFC by another. It emerges that even small misalignments of the surface grid with respect to the shadow edge or "terminator" may greatly improve the accuracy to which the total power to the tile is calculated, hence a strategy for error control emerges which emphasizes meshing with different constraint rather than different size of triangulation.