C
Chris Hegna
Researcher at University of Wisconsin-Madison
Publications - 179
Citations - 6312
Chris Hegna is an academic researcher from University of Wisconsin-Madison. The author has contributed to research in topics: Tokamak & Magnetic field. The author has an hindex of 35, co-authored 175 publications receiving 5750 citations. Previous affiliations of Chris Hegna include University of Colorado Boulder.
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Journal ArticleDOI
Chapter 3: MHD stability, operational limits and disruptions
T. C. Hender,J.C. Wesley,J.M. Bialek,Anders Bondeson,Allen H. Boozer,R.J. Buttery,Am Garofalo,Timothy Goodman,Robert Granetz,Y. Gribov,O. Gruber,Mikhail Gryaznevich,G. Giruzzi,Sibylle Günter,Nobuhiko Hayashi,Per Helander,Chris Hegna,D. F. Howell,D.A. Humphreys,G. T. A. Huysmans,A.W. Hyatt,Akihiko Isayama,Stephen Jardin,Yasunori Kawano,A. Kellman,C.E. Kessel,H. R. Koslowski,R. J. La Haye,E. Lazzaro,Yueqiang Liu,V.E. Lukash,J. Manickam,S. Medvedev,V. Mertens,S. V. Mirnov,Y. Nakamura,G.A. Navratil,M. Okabayashi,Takahisa Ozeki,Roberto Paccagnella,G. Pautasso,F. Porcelli,V. D. Pustovitov,V. Riccardo,M. Sato,Olivier Sauter,M.J. Schaffer,Michiya Shimada,Piergiorgio Sonato,E. J. Strait,M. Sugihara,Manabu Takechi,A. D. Turnbull,E. Westerhof,D.G. Whyte,R. Yoshino,H. Zohm +56 more
TL;DR: A review of recent advances in the area of MHD stability and disruptions, since the publication of the 1999 ITER Physics Basis document (1999 Nucl. Fusion 39 2137-2664), is reviewed in this paper.
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Beta limits in long-pulse tokamak discharges
Olivier Sauter,R. J. LaHaye,Z. Chang,D.A. Gates,Y. Kamada,H. Zohm,Anders Bondeson,D. Boucher,James D. Callen,Ming-Sheng Chu,T. A. Gianakon,O. Gruber,R. W. Harvey,Chris Hegna,L. L. Lao,D. A. Monticello,F. Perkins,A. Pletzer,Allan Reiman,Marshall N. Rosenbluth,E. J. Strait,T. S. Taylor,A. D. Turnbull,Francois Waelbroeck,J. Wesley,H. R. Wilson,R. Yoshino +26 more
TL;DR: In this paper, a quantitative comparison between both the conventional resistive and neoclassical theories, and the experimental results of several machines, which have all observed these low-min nonideal modes.
Journal ArticleDOI
Observation of nonlinear neoclassical pressure-gradient-driven tearing modes in TFTR.
Z. Chang,James D. Callen,E.D. Fredrickson,Robert Budny,Chris Hegna,K. McGuire,M. C. Zarnstorff +6 more
TL;DR: A detailed comparison is made between the tearing-type modes observed in TFTR supershot plasmas and the nonlinear, neoclassical pressure-gradient--driven tearing mode theory, finding good agreement on the non linear evolution of single helicity magnetic islands.
Journal ArticleDOI
Threshold for neoclassical magnetic islands in a low collision frequency tokamak
TL;DR: A kinetic theory for magnetic islands in a low collision frequency tokamak plasma is presented in this article, where selfconsistent equations for the islands' width, w, and propagation frequency, ω, are derived.
Journal ArticleDOI
On the stabilization of neoclassical magnetohydrodynamic tearing modes using localized current drive or heating
Chris Hegna,James D. Callen +1 more
TL;DR: In this article, the effectiveness of using localized current drive or heating to suppress the formation and growth of neoclassical magnetohydrodynamic (MHD) tearing modes is addressed, and the most efficient way to use an auxiliary current source is to cause current to flow in the same direction as the equilibrium bootstrap current and phase the current relative to the magnetic island such that the current is deposited on the O-point of the island.