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Updated: Jul 30, 2026

An Atmospheric Pressure Plasma Setup to Investigate the Reactive Species Formation
Published on: November 3, 2016
Measurement of pressure-gradient-driven currents in tokamak edge plasmas
D M Thomas1, A W Leonard, L L Lao
1General Atomics, PO Box 85608, San Diego, California 92186-5608, USA.
Abstract:
Localized currents driven by pressure gradients play a pivotal role in the magnetohydrodynamic stability of toroidal plasma confinement devices. We have measured the currents generated in the edge of L- (low) and H- (high confinement) mode discharges on the DIII-D tokamak, utilizing the Zeeman effect in an injected lithium beam to obtain high resolution profiles of the poloidal magnetic field. We find current densities in excess of 1 MA/m2 in a 1 to 2 cm region near the peak of the edge pressure gradient. These values are sufficient to challenge edge stability theories based on specific current formation models.
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