Experimental Observation of Neoclassical Currents in a Plasma

Abstract

Experimental observations of the bootstrap and Pfirsch-Schl\"uter currents, predicted by neoclassical transport theory, are presented. Detailed measurements of the parallel plasma currents in a toroidal octupole agree, within the separatrix, with theoretical predictions. Observations of the spatial structure, collisionality, and toroidal field dependence of the complete current and the ion portion of the current are discussed.