Stabilization of Toroidal Currents in High- β Plasmas by Surface Magnetic Fields

Without the imposition of a toroidal magnetic field, a toroidal plasma current is sustained whose maximum current density increases linearly with the applied poloidal surface magnetic field strength. Both plasma compression and heating are observed in the main weak-field region. An average beta near 6% and energy confinement time of 1 msec have been achieved. This concept significantly increases the beta values and the allowable current in toroidal, ohmically heated plasmas.