Oedge modeling of outer wall erosion in NSTX and the effect of changes in neutral pressure

As fusion reactors scale up in size, power, and duty cycle, the quantity of material eroded from the plasma-facing components (PFCs) will rise to levels far above those seen in prior experiments, and could hinder proper operation. While reactor scenarios have been developed that feature significant local re-deposition of particles eroded from high-flux divertor targets, these regimes require near-surface electron densities that are far higher than can be expected at the first wall of the rest of the machine. Without local re-deposition, even small erosion rates at the first wall will present a significant source of migratory material because they are integrated over a large surface area and over long pulse lengths.