Effect of Heating on the Suppression of Tearing Modes in Tokamaks
Abstract
The suppression of (neoclassical) tearing modes is of great importance for the success of future fusion reactors like ITER. Electron cyclotron waves can suppress islands, both by driving noninductive current in the island region and by heating the island, causing a perturbation to the Ohmic plasma current. This Letter reports on experiments on the TEXTOR tokamak, investigating the effect of heating, which is usually neglected. The unique set of tools available on TEXTOR, notably the dynamic ergodic divertor to create islands with a fully known driving term, and the electron cyclotron emission imaging diagnostic to provide detailed 2D electron temperature information, enables a detailed study of the suppression process and a comparison with theory.
- Authors:
- FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, PO Box 1207, 3430 BE Nieuwegein (Netherlands)
- Department of Applied Science, University of California at Davis, Davis, California 95616 (United States)
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)
- Forschungszentrum Juelich GmbH, Institut fuer Plasmaphysik, Association EURATOM-FZJ, D-52425 Juelich (Germany)
- Publication Date:
- OSTI Identifier:
- 20861621
- Resource Type:
- Journal Article
- Resource Relation:
- Journal Name: Physical Review Letters; Journal Volume: 98; Journal Issue: 3; Other Information: DOI: 10.1103/PhysRevLett.98.035001; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; CYCLOTRONS; ELECTRIC CURRENTS; ELECTRON EMISSION; ELECTRON TEMPERATURE; ITER TOKAMAK; NEOCLASSICAL TRANSPORT THEORY; PLASMA HEATING; TEARING INSTABILITY; TEXTOR TOKAMAK
Citation Formats
Classen, I. G. J., Westerhof, E., Donne, A. J. H., Jaspers, R. J. E., Pol, M. J. van de, Spakman, G. W., Domier, C. W., Luhmann, N. C. Jr., Park, H. K., and Jakubowski, M. W.. Effect of Heating on the Suppression of Tearing Modes in Tokamaks. United States: N. p., 2007.
Web. doi:10.1103/PHYSREVLETT.98.035001.
Classen, I. G. J., Westerhof, E., Donne, A. J. H., Jaspers, R. J. E., Pol, M. J. van de, Spakman, G. W., Domier, C. W., Luhmann, N. C. Jr., Park, H. K., & Jakubowski, M. W.. Effect of Heating on the Suppression of Tearing Modes in Tokamaks. United States. doi:10.1103/PHYSREVLETT.98.035001.
Classen, I. G. J., Westerhof, E., Donne, A. J. H., Jaspers, R. J. E., Pol, M. J. van de, Spakman, G. W., Domier, C. W., Luhmann, N. C. Jr., Park, H. K., and Jakubowski, M. W.. Fri .
"Effect of Heating on the Suppression of Tearing Modes in Tokamaks". United States.
doi:10.1103/PHYSREVLETT.98.035001.
@article{osti_20861621,
title = {Effect of Heating on the Suppression of Tearing Modes in Tokamaks},
author = {Classen, I. G. J. and Westerhof, E. and Donne, A. J. H. and Jaspers, R. J. E. and Pol, M. J. van de and Spakman, G. W. and Domier, C. W. and Luhmann, N. C. Jr. and Park, H. K. and Jakubowski, M. W.},
abstractNote = {The suppression of (neoclassical) tearing modes is of great importance for the success of future fusion reactors like ITER. Electron cyclotron waves can suppress islands, both by driving noninductive current in the island region and by heating the island, causing a perturbation to the Ohmic plasma current. This Letter reports on experiments on the TEXTOR tokamak, investigating the effect of heating, which is usually neglected. The unique set of tools available on TEXTOR, notably the dynamic ergodic divertor to create islands with a fully known driving term, and the electron cyclotron emission imaging diagnostic to provide detailed 2D electron temperature information, enables a detailed study of the suppression process and a comparison with theory.},
doi = {10.1103/PHYSREVLETT.98.035001},
journal = {Physical Review Letters},
number = 3,
volume = 98,
place = {United States},
year = {Fri Jan 19 00:00:00 EST 2007},
month = {Fri Jan 19 00:00:00 EST 2007}
}
-
A study is made of the suppression of neoclassical tearing modes in tokamaks under anomalous transverse transport conditions when the magnetic well effect predominates over the bootstrap drive. It is stressed that the corresponding effect, which is called the compound suppression effect, depends strongly on the profiles of the electron and ion temperature perturbations. Account is taken of the fact that the temperature profile can be established as a result of the competition between anomalous transverse heat transport, on the one hand, and longitudinal collisional heat transport, longitudinal heat convection, longitudinal inertial transport, and transport due to the rotation ofmore »
-
Stability of coupled tearing and twisting modes in tokamaks
A dispersion relation is derived for resistive modes of arbitrary parity in a tokamak plasma. At low mode amplitude, tearing and twisting modes which have nonideal magnetohydrodynamical (MHD) behavior at only one rational surface at a time in the plasma are decoupled via sheared rotation and diamagnetic flows. At higher amplitude, more unstable compound'' modes develop which have nonideal behavior simultaneously at many surfaces. Such modes possess tearing parity layers at some of the nonideal surfaces, and twisting parity layers at others, but mixed parity layers are generally disallowed. At low mode number, compound'' modes are likely to have tearingmore » -
Stability of multihelical tearing modes in shaped tokamaks
The stability of multihelical tearing modes in tokamaks with shaped cross sections is determined numerically. The method allows inclusion of a large number of singular surfaces resolved with high accuracy. Poloidal and radial couplings are discussed and the convergence is well understood. Modes of high poloidal m number are found to be unstable for typical equilibria. Completely stable current distributions have been constructed for D-shaped plasmas. -
Comment on ``Stability of coupled tearing and twisting modes in tokamaks`` [Phys. Plasmas {bold 1}, 3308 (1994)]
Recently an incorrect dispersion relation (Ref. 2 and 3) was used in a publication by Connor {ital et} {ital al}. (Ref. 1) for toroidally coupled tearing and twisting modes. The aim of this comment is to pointout how this incorrect assumption affects the derivation of the coupled modes. (AIP) -
Response to ``Comment on `Stability of coupled tearing and twisting modes in tokamaks``` [Phys. Plasmas {bold 1}, 3308 (1994)]
The authors contend that incorrect inferences are drawn by Ding Li regarding the sources of error and of the basis function method used in the calculations of toroidally coupled tearing modes. (AIP)