Tokamak plasma magnetics

High-beta MHD equilibria in Tokamaks of circular and noncircular cross section are discussed, with particular emphasis on 'flux-conserving-Tokamak' (FCT) equilibria. The poloidal-field systems required to contain high-beta plasmas are investigated along with optimization of a whole poloidal-field coil system and the STATIC system for reducing both the pulsed fields at the toroidal-field coil windings and the plasma volt-second requirements. Toroidal-field ripple effects on plasma transport and fast-ion containment are treated, and the largely unrecognized effects of magnetic-field ripple on alpha-particle drift orbits and their containment during the deceleration process are investigated. It is concluded that beta values as large as 20% to 30% are possible with FCT equilibria, which emerge naturally from the intense heating process.