OBSERVATION AND ANALYSIS OF PARTICLE DRIFT ISLANDS IN A TORSATRON

Magnetic islands in toroidal plasma confinement devices are generated by resonant magnetic error fields. Energetic particle drift surfaces c an differ substantially from magnetic flux surfaces. In this Letter th e first direct measurement of islands in energetic particle drift surf aces are presented. The understanding of these drift islands is import ant for the optimization of plasma confinement. These drift islands ar e demonstrated to form in energetic electron drift surfaces as a resul t of resonant magnetic field perturbations and resonant, applied elect ric field perturbations. The results, once corrected for inherent magn etic error fields, agree well with theoretical predictions. (C) 1995 A merican Institute of Physics.