Confinement of a self‐stabilized tokamak under average magnetic well conditions

It is well known that the average favorable magnetic curvature of a tokamak is stabilizing with respect to pressure‐driven magnetohydrodynamic instabilities at low beta and that self‐stabilization occurs at finite beta in the so‐called second stability regime. Here it is self‐consistently investigated how these two effects, viz., the mean magnetic well and the self‐stabilization, influence the energy confinement time in a tokamak, with the use of the ballooning mode transport model proposed by Connor, Taylor, and Turner [Nucl. Fusion 2 4, 642 (1984)].