Non-axisymmetric equilibrium reconstruction of a current-carrying stellarator using external magnetic and soft x-ray inversion radius measurements

Journal Article · Tue Dec 15 00:00:00 EST 2015 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4938031· OSTI ID:22489930

Maurer, D. A.; Knowlton, S. F.; ArchMiller, M. C.; Ennis, D. A.; Hanson, J. D.; Hartwell, G. J.; Hebert, J. D.; Herfindal, J. L.; Pandya, M. D.; Roberds, N. A.; Traverso, P. J. ^[1]; Cianciosa, M. R. ^[2]

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1. Physics Department, Auburn University, Auburn, Alabama 36849 (United States)
2. Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37830 (United States)

Non-axisymmetric free-boundary equilibrium reconstructions of stellarator plasmas are performed for discharges in which the magnetic configuration is strongly modified by ohmically driven plasma current. These studies were performed on the compact toroidal hybrid device using the V3FIT reconstruction code with a set of 50 magnetic diagnostics external to the plasma. With the assumption of closed magnetic flux surfaces, the reconstructions using external magnetic measurements allow accurate estimates of the net toroidal flux within the last closed flux surface, the edge safety factor, and the plasma shape of these highly non-axisymmetric plasmas. The inversion radius of standard sawteeth is used to infer the current profile near the magnetic axis; with external magnetic diagnostics alone, the current density profile is imprecisely reconstructed.

• OSTI ID: 22489930
• Journal Information: Physics of Plasmas, Vol. 22, Issue 12; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
AXIAL SYMMETRY
CURRENT DENSITY
ELECTRIC CURRENTS
MAGNETIC FLUX
MAGNETIC SURFACES
PLASMA
SAWTOOTH OSCILLATIONS
SOFT X RADIATION
STELLARATORS