Resolve divertor localization and neutron-wall-load peaking

Characterize divertor localization and peaking factors for neutron wall loading in advanced quasi-isodynamic stellarators, so that the core-averaged wall-load estimate can be replaced by a spatially resolved engineering assessment.

Background

The paper estimates neutron wall loading by dividing the non-alpha fusion power by the first-wall area. For scaled quasi-isodynamic equilibria, the wall area is obtained from a prescribed plasma–wall gap, while the analytic geometry option uses an elongated-torus proxy.

The authors explicitly state that divertor localization and peaking factors have not been resolved. Consequently, the reported neutron wall load is only a core-averaged indicator suitable for early sizing, leaving the spatial distribution and local maxima of wall loading as an unresolved engineering problem.