A review of plasma–wall boundary effects on core confinement and lithium applications to boundary-controlled magnetic fusion experiments

Reduced particle recycling in the edge region is often considered to be a necessary condition to achieve high-performance confinement in magnetic fusion experiments. However, it is also true that whenever or however core confinement improves, as a result edge recycling is reduced. To provide a logical interpretation of this circular cause-and-consequence relation, reviewed in this paper are some of the important data demonstrating plasma–wall boundary effects on core confinement and also those evaluating innovative wall concepts with lithium applied to sustain optimized boundary conditions for the operation of steady-state fusion power reactors.