Multifield measurement of magnetic fluctuation-induced particle flux in a high-temperature toroidal plasma. (20th September 2016)

• Record Type: Journal Article
• Authors: Lin, L.; Ding, W.X.; Brower, D.L.
• Is Part Of: Nuclear fusion. Volume 56:Number 12(2016:Dec.)
• Publication Date: 2016-09-20
• Subjects: fluctuations -- transport -- turbulence -- magnetic; Nuclear fusion -- Periodicals; 621.48405
• DOI: 10.1088/0029-5515/56/12/126020
• Languages: English
• ISSNs: 0029-5515

Abstract

Abstract: Magnetic fluctuation-induced particle transport is explored in the high-temperature, high-beta interior of the Madison symmetric torus (MST) reversed-field pinch by performing a multifield measurement of the correlated product of magnetic and density fluctuations associated with global resistive tearing modes. Local density fluctuations are obtained by inverting the line-integrated interferometry data after resolving the mode helicity through correlation techniques. The local magnetic and current density fluctuations are then reconstructed using a parameterized fit of Faraday-effect polarimetry measurements. Reconstructed 2D images of density and current density perturbations in a poloidal cross section exhibit significantly different spatial structure. Combined with their relative phase, the magnetic-fluctuation-induced particle transport flux and its spatial distribution are resolved. The convective magnetic fluctuation-induced particle flux profile is measured for both standard and high-performance plasmas in MST with tokamak-like confinement, showing large reduction in the flux during improved confinement.