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

Hansen, C.; Boyle, D. P.; Schmitt, J. C.; Majeski, R.

doi:10.1063/1.4981214

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

Journal Article · Tue Apr 18 00:00:00 EDT 2017 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4981214· OSTI ID:1358666

^[1]; ^[2]; Schmitt, J. C. ^[3]; Majeski, R. ^[2]

Univ. of Washington, Seattle, WA (United States); Columbia Univ., New York, NY (United States)
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
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.

View Accepted Manuscript (DOE)

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) (SC-24)

Grant/Contract Number:: AC02-09CH11466; SC0016256

OSTI ID:: 1358666

Alternate ID(s):: OSTI ID: 1608228
OSTI ID: 1361829

Journal Information:: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 4 Vol. 24; ISSN 1070-664X

Publisher:: American Institute of Physics (AIP)Copyright Statement

Country of Publication:: United States

Language:: English

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Cited By (2)

Magnetic perturbation diagnostics in the high-temperature lithiated environment of LTX- β Hughes, P. E.; Majeski, R.; Kaita, R. Review of Scientific Instruments, Vol. 89, Issue 10 https://doi.org/10.1063/1.5035359	journal	October 2018
Observation of Flat Electron Temperature Profiles in the Lithium Tokamak Experiment Boyle, D. P.; Majeski, R.; Schmitt, J. C. Physical Review Letters, Vol. 119, Issue 1 https://doi.org/10.1103/physrevlett.119.015001	journal	July 2017

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