Non-resonant QA divertor resiliency for the Helios planar coil stellarator

Fusion power plants (FPPs) will have large thermal and particle loads that must be exhausted without melting wall components. For this purpose, divertor designs must consider methods for dissipating heat fluxes, minimizing neutral back-streaming, and preventing impurity transport upstream into the core. Non-axisymmetric devices, such as stellarators, face the additional challenge of handling toroidally varying heat and particle fluxes that enter the scrape-off layer of the plasma. While the choice of quasi-axisymmetric (QA) stellarators vastly simplifies coil manufacturing, island divertor designs cannot be used. The initial non-resonant QA divertor design developed at Thea Energy will be tested for resiliency to plasma profile and beta changes, as well as error fields, to investigate the effect of current ramping on the divertor region. Poincaré sections and divertor heat loading estimates (performed with field line diffusion) will be shown for a variety of different configurations.