Dynamic Electrostatic Confinement in an rf-Sustained Tandem Mirror

Abstract

Electrostatic ion confinement is demonstrated in an rf-sustained tandem mirror and shown to have a dynamic nature. Measurements of plasma potential and ion end loss on particular flux tubes show that confinement can be enhanced by a factor of 3 over direct-flow loss rates. The axial confining potential can vary with radial position and time resulting in changes in ion confinement with abrupt reductions in central-cell plasma density when axial potential confinement is reduced.