skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

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

Journal Article · · Physics of Plasmas
DOI:https://doi.org/10.1063/1.4938031· OSTI ID:1263869

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.

Research Organization:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
USDOE Office of Science (SC)
Grant/Contract Number:
AC05-00OR22725
OSTI ID:
1263869
Journal Information:
Physics of Plasmas, Vol. 22, Issue 12; ISSN 1070-664X
Publisher:
American Institute of Physics (AIP)Copyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 6 works
Citation information provided by
Web of Science

References (23)

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
The theory of variances in equilibrium reconstruction journal September 2008
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
A 3D approach to equilibrium, stability and transport studies in RFX-mod improved regimes journal November 2010
Magnetic Diagnostics for Equiibrium Reconstruction at W7-X journal July 2010
Recent advances in the design of quasiaxisymmetric stellarator plasma configurations journal May 2001
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
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
Turbulence, Coherent Structures, Dynamical Systems and Symmetry book January 2010
Design and implementation of a multichannel millimeter wave interferometer for the Compact Toroidal Hybrid experiment journal October 2012
Thomson scattering diagnostic system design for the Compact Toroidal Hybrid experiment journal November 2014
Positional Stability of a Current-Carrying Plasma in an l =2 Stellarator Field journal August 1980
Equilibrium and Stability of Current-Carrying Discharges in the Non-Axisymmetric CTH Experiment journal July 2010
Disruptive MHD activity during plasma current rise in Alcator A tokamak journal December 1979
Modeling of active control of external magnetohydrodynamic instabilities journal May 2001
Calculation of Eddy Currents in the CTH Vacuum Vessel and Coil Frame for Use in MHD Equilibrium Reconstruction of the Plasma Discharge journal September 2013
Magnetic diagnostics: General principles and the problem of reconstruction of plasma current and pressure profiles in toroidal systems journal June 2001

Cited By (2)

Determination of current and rotational transform profiles in a current-carrying stellarator using soft x-ray emissivity measurements journal January 2018
3D equilibrium reconstruction with islands journal March 2018