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

摘要

The neoclassical magnetohydrodynamic equilibrium of reversed-field pinch (RFP) is self-consistently solved considering the self-induced plasma current I-phi(SI) in a reactor relevant parameter regime. The current I-phi(SI) consists of bootstrap currents due to alpha 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-phi(SI) in a low-aspect-ratio RFP (aspect ratio A=2), when beta is high. An I-phi(SI) as high as 94.4% of the plasma current in the equilibrium with ellipticity kappa=1.4 and triangularity delta=0.4 is obtained with a flat pressure profile, which provides a toroidal beta of beta(t)=63% (volume-averaged beta, =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 beta. (c) 2005 American Institute of Physics.