Modeling particle and power exhaust in stellarator fusion power plant

Effective plasma exhaust is a key requirement for the development of stellarator based fusion energy. The stellarator divertor needs to ensure that 1) the heat flux plasma facing components (PFCs) is below engineering limits, 2) the energy of plasma particle that impact the wall are below the limit that produces physical sputtering, 3) wall-generated impurities do not penetrate to the core plasma and 4) adequate neutral pressure exists to pump neutrals. To evaluate reactor concepts, we use various established techniques. These include field-line diffusion modeling, where artificial diffusion is added to a field-line following module to simulate particle transport; and also, EMC3-lite, a simulation tool that can calculate the heat flux on plasma surfaces. The application of these tools on an example equilibrium is shown.