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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 Laboratory (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. https://doi.org/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. 2015. "Non-axisymmetric equilibrium reconstruction of a current-carrying stellarator using external magnetic and soft x-ray inversion radius measurements". United States. https://doi.org/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},
url = {https://www.osti.gov/biblio/1263869}, journal = {Physics of Plasmas},
issn = {1070-664X},
number = 12,
volume = 22,
place = {United States},
year = {Tue Dec 22 00:00:00 EST 2015},
month = {Tue Dec 22 00:00:00 EST 2015}
}

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Cited by: 6 works
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Works referenced in this record:

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Works referencing / citing this record:

3D equilibrium reconstruction with islands
journal, March 2018