Journal ArticleDOI
Separation of β̄p and ℓi in tokamaks of non-circular cross-section
TLDR
In this paper, integral relations for the average poloidal beta p and the plasma internal inductance li are derived from the magnetohydrodynamic (MHD) equilibrium equation for an axisymmetric torus.Abstract:
Integral relations for the average poloidal beta p and the plasma internal inductance li are derived from the magnetohydrodynamic (MHD) equilibrium equation for an axisymmetric torus. The volume-dependent parameters that appear depend only weakly on the actual current density distribution inside the plasma and can be evaluated approximately, given the plasma shape and boundary poloidal magnetic field. In practice, these can be accurately and efficiently obtained for both diverted and limited plasmas from measured external poloidal magnetic field and flux values by approximating the plasma current distribution using a few filaments or distributed sources. For a tokamak plasma with a non-circular cross-section of sufficient elongation, p and li can then be approximately determined separately. This is demonstrated for analytic equilibria of known shape as well as for actual Doublet III (D-III) plasmas for which p and li have been determined by using other methods. Results of a sensitivity study are described.read more
Citations
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Journal ArticleDOI
Reconstruction of current profile parameters and plasma shapes in tokamaks
TL;DR: In this paper, an efficient method is given to reconstruct the current profile parameters, the plasma shape, and a current profile consistent with the magnetohydrodynamic equilibrium constraint from external magnetic measurements, based on a Picard iteration approach.
Journal ArticleDOI
Equilibrium analysis of current profiles in tokamaks
TL;DR: In this paper, an efficient method is given for self-consistent reconstruction of the tokamak current profiles and their associated magnetic topology using the magnetohydrodynamic (MHD) equilibrium constraint from external magnetic measurements, kinetic profile measurements, internal poloidal magnetic field measurements, and topological information from soft X-ray (SXR) measurements.
Journal ArticleDOI
MHD Equilibrium Reconstruction in the DIII-D Tokamak
L. L. Lao,H.E. St. John,Q. Peng,J.R. Ferron,E. J. Strait,T. S. Taylor,W. H. Meyer,Chuanguo Zhang,K. I. You +8 more
TL;DR: In this paper, the development of axisymmetric magnetohydrodynamic equilibrium reconstruction to support plasma operation and data analysis in the DIII-D tokamak is discussed.
Journal ArticleDOI
Low voltage Ohmic and electron cyclotron heating assisted startup in DIII-D
TL;DR: In this paper, a low voltage Ohmic startup at E = 0.3 V/m with |B⊥| > 50 G over most of the vessel cross-section has been demonstrated.
Journal ArticleDOI
Equilibrium properties of spherical torus plasmas in NSTX
Steven Sabbagh,Stanley Kaye,Jonathan Menard,F. Paoletti,M.G. Bell,R. E. Bell,J.M. Bialek,Manfred Bitter,E.D. Fredrickson,D.A. Gates,Alan H. Glasser,H.W. Kugel,L. L. Lao,B.P. LeBlanc,R. Maingi,Ricardo Maqueda,E. Mazzucato,D. Mueller,Masayuki Ono,S.F. Paul,M. Peng,C.H. Skinner,Dan Stutman,G. A. Wurden,W. Zhu +24 more
TL;DR: In this paper, the evolution of the plasma equilibrium between discharges is analyzed with an automated version of the EFIT code and reconstructed magnetic signals are fitted to the corresponding measured values with low errors.
References
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Journal ArticleDOI
An efficient technique for magnetic analysis of non-circular, high-beta tokamak equilibria
D.W. Swain,G.H. Neilson +1 more
TL;DR: In this paper, a method for determining plasma shape and global properties of high-beta non-circular tokamak equilibria (βp, β, q and li) from magnetic sensor data is described.
Journal ArticleDOI
Variational moment solutions to the Grad–Shafranov equation
TL;DR: In this paper, a variational method is developed to find approximate solutions to the Grad-Shafranov equation, where the surfaces of the constant poloidal magnetic flux ψ(R, Z) are obtained by solving a few ordinary differential equations.
Journal ArticleDOI
Magnetic analysis of non-circular cross-section tokamaks
J.L. Luxon,B.B. Brown +1 more
TL;DR: In this paper, the MHD equilibrium configuration for circular and non-circular plasmas from measurements of the magnetic field and flux made outside the discharge was determined using least squares minimization techniques.
Journal Article
Equilibrium of a toroidal plasma with noncircular cross section
L. E. Zakharov,V. D. Shafranov +1 more
TL;DR: The possibility of determining the cross-sectional form of a Tokamak plasma from measurements of the magnetic field outside the plasma is indicated in this article, where two kinds of integral relation are obtained.
Journal ArticleDOI
Determination of the parameters βI and li in a Tokamak for arbitrary shape of plasma pinch cross-section
TL;DR: In this article, the pressure balance equation and relation between the measured external magnetic field of a toroidal plasma column and its inductance were found for the general case of an arbitrary departure from cylindrical symmetry.