PLASMA CONTAINMENT IN A MINIMUM-B GEOMETRY.

Abstract : The advantages of a toroidal plasma containment device are illustrated. Low loss rates are predicted. A toroidal magnetic field is crossed with a multi-cusp magnetic field in configurations predicted by electrolytic tank analog experiments. Three such configurations are described. The first, a relatively simple device with slowly varying fields, showed the inability of the toroidal field to penetrate a plasma and strong cusp field. The second toroid, with moderately fast fields and application of rotational transform principles, produced plasma-field separation, as evidenced by a hot, relatively dense plasma contained in a central region of reduced cusp field strength. The third toroid, featuring the fastest rising fields, produced similar though more pronounced results, including a three fold compression of a plasma heated to over 15 eV, with containment times on the order of 20 microsec. (Author)