Field Line Mapping and Edge Modeling for Helias Configurations

Tracing magnetic field lines between divertor plates and characterizing them according to their lengths shows that an ordered‐layer structure of the field lines in the edge region of Helias stellarators prevails. Because of the layer structure these field lines are used as coordinate lines for plasma edge modeling: in a first attempt, the temperature, density and velocity along the field lines are calculated by solving simple 1D particle and energy transport equations along 3D field lines. Combining these 1D calculations with complementary Monte Carlo methods, which allow simulation of transport across the field lines, yields a 3D scrape‐off layer description encompassing parallel and cross‐field transport.