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Title: Equilibrium reconstruction with 3D eddy currents in the Lithium Tokamak eXperiment

Journal Article · · Physics of Plasmas
DOI:https://doi.org/10.1063/1.4981214· OSTI ID:1358666
ORCiD logo [1]; ORCiD logo [2];  [3];  [2]
  1. Univ. of Washington, Seattle, WA (United States); Columbia Univ., New York, NY (United States)
  2. Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
  3. Auburn Univ., AL (United States)

Axisymmetric free-boundary equilibrium reconstructions of tokamak plasmas in the Lithium Tokamak eXperiment (LTX) are performed using the PSI-Tri equilibrium code. Reconstructions in LTX are complicated by the presence of long-lived non-axisymmetric eddy currents generated by a vacuum vessel and first wall structures. To account for this effect, reconstructions are performed with additional toroidal current sources in these conducting regions. The eddy current sources are fixed in their poloidal distributions, but their magnitude is adjusted as part of the full reconstruction. Eddy distributions are computed by toroidally averaging currents, generated by coupling to vacuum field coils, from a simplified 3D filament model of important conducting structures. The full 3D eddy current fields are also used to enable the inclusion of local magnetic field measurements, which have strong 3D eddy current pick-up, as reconstruction constraints. Using this method, equilibrium reconstruction yields good agreement with all available diagnostic signals. Here, an accompanying field perturbation produced by 3D eddy currents on the plasma surface with a primarily n = 2, m = 1 character is also predicted for these equilibria.

Research Organization:
Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States); Univ. of Washington, Seattle, WA (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Fusion Energy Sciences (FES)
Grant/Contract Number:
SC0016256; AC02-09CH11466
OSTI ID:
1358666
Alternate ID(s):
OSTI ID: 1361829; OSTI ID: 1608228
Journal Information:
Physics of Plasmas, Vol. 24, Issue 4; ISSN 1070-664X
Publisher:
American Institute of Physics (AIP)Copyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 14 works
Citation information provided by
Web of Science

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Cited By (2)

Magnetic perturbation diagnostics in the high-temperature lithiated environment of LTX- β journal October 2018
Observation of Flat Electron Temperature Profiles in the Lithium Tokamak Experiment journal July 2017