Journal ArticleDOI
Reconstruction of current profile parameters and plasma shapes in tokamaks
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TLDR
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.Abstract:
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 which approximately conserves the measurements. Computational efforts are reduced by parametrizing the current profile linearly in terms of a number of physical parameters. Results of detailed comparative calculations and a sensitivity study are described. Illustrative calculations to reconstruct the current profiles and plasma shapes in ohmically and auxiliarily heated Doublet III plasmas are given which show many interesting features of the current profiles.read more
Citations
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Journal ArticleDOI
MHD-induced energetic ion loss during H-mode discharges in the National Spherical Torus Experiment
S. S. Medley,N. N. Gorelenkov,R. Andre,R.E. Bell,D. S. Darrow,E.D. Fredrickson,S.M. Kaye,B.P. LeBlanc,A. L. Roquemore +8 more
TL;DR: In this paper, the effect of magnetohydrodynamic (MHD) induced ion loss in neutral beam heated H-mode discharges in the National Spherical Torus Experiment (NSTX) is discussed.
Proceedings ArticleDOI
Control of plasma poloidal shape and position in the DIII-D tokamak
TL;DR: In this paper, the authors discuss the techniques used now and in the past to control plasma shape and position of the DIII-D tokamak plasmas and conjecture that a model only slightly more sophisticated than the rigid radial response plasma used here is necessary, except perhaps for detailed control of field lines around the X-point.
Journal ArticleDOI
Measurement and control of the fast ion redistribution on MAST
M. Turnyanskiy,C. D. Challis,R. J. Akers,Marco Cecconello,D. L. Keeling,A. Kirk,R. Lake,S. D. Pinches,S. Sangaroon,I. Wodniak +9 more
TL;DR: In this article, it was shown that broadening the fast ion pressure profile by the application of neutral beam injection at an off-axis location can mitigate the growth of these modes and result in the classical fast ion behaviour.
Journal ArticleDOI
Ideal MHD stability of the mega-ampere spherical tokamak
Matthew Hole,R. Akers,L.C. Appel,R.J. Buttery,C. Brickley,N. J. Conway,Mikhail Gryaznevich,T. C. Hender,Ohjin Kwon,M. Valovic,S. Medvedev,A. Patel,S. Saarelma,D Taylor,H. R. Wilson +14 more
TL;DR: In this article, three techniques that refine the magnetic reconstruction of the mega-ampere spherical tokamak (MAST) equilibrium are detailed: kinetic reconstruction, in which the thermal pressure profile is fitted to thermal electron and ion data; bootstrap (BS) reconstruction, which the edge current profile is modified to be self-consistent with the BS fraction (in the limit that edge current is BS dominated); and fast-particle reconstruction, where an effective fast-ion pressure component is added, representing ions driven by charge exchange of the thermal ions with injected neutrals
Journal ArticleDOI
Investigation of electron parallel pressure balance in the scrapeoff layer of deuterium-based radiative divertor discharges in DIII-D
T.W. Petrie,S.L. Allen,T. N. Carlstrom,D. N. Hill,R. Maingi,D. G. Nilson,M. D. Brown,Dean A. Buchenauer,Todd Evans,M.E. Fenstermacher,R.A. Jong,C.J. Lasnier,A.W. Leonard,M.A. Mahdavi,G.D. Porter,M. R. Wade,W.P. West +16 more
TL;DR: In this paper, electron density, temperature and parallel pressure measurements at several locations along field lines connecting the midplane scrapeoff layer (SOL) with the outer divertor are presented for both attached and partially-detached divertor cases.
References
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Journal ArticleDOI
Separation of β̄p and ℓi in tokamaks of non-circular cross-section
TL;DR: 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.
Journal ArticleDOI
Computation of ideal MHD equilibria
TL;DR: In this paper, a review of two-and three-dimensional ideal MHD equilibrium codes, with particular emphasis on axisymmetric toroidal calculations, is presented. But this paper is restricted to the case of Tokyoamak geometry.
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
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.
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