Neoclassical reversed-field pinch equilibrium with dominant self-induced plasma current.

The neoclassical magnetohydrodynamic equilibrium of reversed-field pinch (RFP) is self-consistently solved considering the self-induced plasma current I_{[lowercase_phi_synonym]}^SI in a reactor relevant parameter regime. The current I_{[lowercase_phi_synonym]}^SI consists of bootstrap currents due to α particles as well as the bulk plasma, where the conventional neoclassical transport theory is applied without considering the finite banana-width effect, Pfirsch–Schluter current, and diamagnetic current. The neoclassical effect enhances I_{[lowercase_phi_synonym]}^SI in a low-aspect-ratio RFP (aspect ratio A=2), when β is high. An I_{[lowercase_phi_synonym]}^SI as high as 94.4% of the plasma current in the equilibrium with ellipticity κ=1.4 and triangularity δ=0.4 is obtained with a flat pressure profile, which provides a toroidal β of β_t=63% (volume-averaged β, 〈β〉=66%) stable against both the ideal kink mode and Mercier mode. This dominant self-induced current makes the steady-state approach feasible. Its hollow current profile gives a strong magnetic shear and a high-stability β. [ABSTRACT FROM AUTHOR]