skip to main content

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

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.
Authors:
; ; ; ; ; ; ; ; ; ; ;  [1] ;  [2]
  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)
Publication Date:
OSTI Identifier:
22489930
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 22; Journal Issue: 12; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; AXIAL SYMMETRY; CURRENT DENSITY; ELECTRIC CURRENTS; MAGNETIC FLUX; MAGNETIC SURFACES; PLASMA; SAWTOOTH OSCILLATIONS; SOFT X RADIATION; STELLARATORS