Transport Barriers Formation and Subneoclassical Energy Fluxes: A Unified Theoretical Approach

We show that “subneoclassical” heat fluxes are rigorous and straightforward consequences of the revisited neoclassical theory—including finite Larmor radius (FLR) and inertia effects—that we published earlier [Phys. Plasmas 1, 619 (1994)]. The formation of sheared radial electric field profiles displaying most of the characteristics observed in the transport barriers associated with $L-\mathrm{to}-H$ transitions is another consequence of this first principles theory. The threshold condition results from a competition between rotation spin-up related to FLR and friction by charge-exchange neutrals.