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

Abstract

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. Lastly, the inversion radius of standard saw-teeth 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];  [1];  [1];  [1];  [1];  [1];  [1];  [1];  [1];  [1];  [1];  [1];  [2]
  1. Auburn Univ., Auburn, AL (United States)
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1263869
Grant/Contract Number:  
AC05-00OR22725
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 22; Journal Issue: 12; Journal ID: ISSN 1070-664X
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; plasma diagnostics; coils; eddies; stellarators; three dimensional image processing

Citation Formats

Ma, X., Maurer, D. A., Knowlton, Stephen F., ArchMiller, M. C., Ennis, D. A., Hanson, J. D., Hartwell, G. J., Hebert, J. D., Herfindal, J. L., Pandya, M. D., Roberts, N. A., Traverso, P. J., and Cianciosa, M. R. Non-axisymmetric equilibrium reconstruction of a current-carrying stellarator using external magnetic and soft x-ray inversion radius measurements. United States: N. p., 2015. Web. doi:10.1063/1.4938031.
Ma, X., Maurer, D. A., Knowlton, Stephen F., ArchMiller, M. C., Ennis, D. A., Hanson, J. D., Hartwell, G. J., Hebert, J. D., Herfindal, J. L., Pandya, M. D., Roberts, N. A., Traverso, P. J., & Cianciosa, M. R. Non-axisymmetric equilibrium reconstruction of a current-carrying stellarator using external magnetic and soft x-ray inversion radius measurements. United States. doi:10.1063/1.4938031.
Ma, X., Maurer, D. A., Knowlton, Stephen F., ArchMiller, M. C., Ennis, D. A., Hanson, J. D., Hartwell, G. J., Hebert, J. D., Herfindal, J. L., Pandya, M. D., Roberts, N. A., Traverso, P. J., and Cianciosa, M. R. Tue . "Non-axisymmetric equilibrium reconstruction of a current-carrying stellarator using external magnetic and soft x-ray inversion radius measurements". United States. doi:10.1063/1.4938031. https://www.osti.gov/servlets/purl/1263869.
@article{osti_1263869,
title = {Non-axisymmetric equilibrium reconstruction of a current-carrying stellarator using external magnetic and soft x-ray inversion radius measurements},
author = {Ma, X. and Maurer, D. A. and Knowlton, Stephen F. and ArchMiller, M. C. and Ennis, D. A. and Hanson, J. D. and Hartwell, G. J. and Hebert, J. D. and Herfindal, J. L. and Pandya, M. D. and Roberts, N. A. and Traverso, P. J. and Cianciosa, M. R.},
abstractNote = {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. Lastly, the inversion radius of standard saw-teeth is used to infer the current profile near the magnetic axis; with external magnetic diagnostics alone, the current density profile is imprecisely reconstructed.},
doi = {10.1063/1.4938031},
journal = {Physics of Plasmas},
issn = {1070-664X},
number = 12,
volume = 22,
place = {United States},
year = {2015},
month = {12}
}

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Works referenced in this record:

Equilibrium analysis of current profiles in tokamaks
journal, June 1990


Equilibrium properties of spherical torus plasmas in NSTX
journal, November 2001


Accuracy of EFIT equilibrium reconstruction with internal diagnostic information at JET
journal, October 2008

  • Brix, M.; Hawkes, N. C.; Boboc, A.
  • Review of Scientific Instruments, Vol. 79, Issue 10
  • DOI: 10.1063/1.2964180

The theory of variances in equilibrium reconstruction
journal, September 2008

  • Zakharov, Leonid E.; Lewandowski, Jerome; Foley, Elizabeth L.
  • Physics of Plasmas, Vol. 15, Issue 9
  • DOI: 10.1063/1.2977480

Equilibrium reconstruction in the Madison Symmetric Torus reversed field pinch
journal, December 2003


Non-axisymmetric equilibrium reconstruction for stellarators, reversed field pinches and tokamaks
journal, July 2013


Modeling, measurement, and 3-D equilibrium reconstruction of the bootstrap current in the Helically Symmetric Experiment
journal, September 2014

  • Schmitt, J. C.; Talmadge, J. N.; Anderson, D. T.
  • Physics of Plasmas, Vol. 21, Issue 9
  • DOI: 10.1063/1.4895899

A 3D approach to equilibrium, stability and transport studies in RFX-mod improved regimes
journal, November 2010


Recent advances in the design of quasiaxisymmetric stellarator plasma configurations
journal, May 2001

  • Reiman, A.; Ku, L.; Monticello, D.
  • Physics of Plasmas, Vol. 8, Issue 5
  • DOI: 10.1063/1.1351826

V3FIT: a code for three-dimensional equilibrium reconstruction
journal, July 2009


Design and initial operation of a two-color soft x-ray camera system on the Compact Toroidal Hybrid experiment
journal, November 2014

  • Herfindal, J. L.; Dawson, J. D.; Ennis, D. A.
  • Review of Scientific Instruments, Vol. 85, Issue 11
  • DOI: 10.1063/1.4892540

Three-dimensional free boundary calculations using a spectral Green's function method
journal, December 1986


MOMCON: A spectral code for obtaining three-dimensional magnetohydrodynamic equilibria
journal, February 1986


Design and implementation of a multichannel millimeter wave interferometer for the Compact Toroidal Hybrid experiment
journal, October 2012

  • Miller, M. C.; Hanson, J. D.; Hartwell, G. J.
  • Review of Scientific Instruments, Vol. 83, Issue 10
  • DOI: 10.1063/1.4732056

Thomson scattering diagnostic system design for the Compact Toroidal Hybrid experiment
journal, November 2014

  • Traverso, P. J.; Maurer, D. A.; Ennis, D. A.
  • Review of Scientific Instruments, Vol. 85, Issue 11
  • DOI: 10.1063/1.4892161

Equilibrium and Stability of Current-Carrying Discharges in the Non-Axisymmetric CTH Experiment
journal, July 2010

  • Hanson, J. D.; Knowlton, S. F.; Stevenson, B. A.
  • Contributions to Plasma Physics, Vol. 50, Issue 8
  • DOI: 10.1002/ctpp.200900059

Modeling of active control of external magnetohydrodynamic instabilities
journal, May 2001

  • Bialek, James; Boozer, Allen H.; Mauel, M. E.
  • Physics of Plasmas, Vol. 8, Issue 5
  • DOI: 10.1063/1.1362532

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    Determination of current and rotational transform profiles in a current-carrying stellarator using soft x-ray emissivity measurements
    journal, January 2018

    • Ma, X.; Cianciosa, M. R.; Ennis, D. A.
    • Physics of Plasmas, Vol. 25, Issue 1
    • DOI: 10.1063/1.5013347

    Development of a non-parametric Gaussian process model in the three-dimensional equilibrium reconstruction code V3FIT
    journal, January 2020