Preliminary engineering design of the first wall and X-point divertor of the Helios planar coil stellarator

“Helios” is a two-field-period, quasi-axisymmetric (“QA”) planar coil stellarator power plant that features a novel, toroidally-continuous, non-resonant X-point divertor isomorphic to that of a tokamak with resonant magnetic perturbations. This work describ…