Heat pulse propagation across the rational surface in a large helical device plasma with counter-neutral beam injection
- Department of Fusion Science, School of Mathematical and Physical Science, Graduate University for Advanced Studies, Hayama 240-0193 (Japan)
Core electron temperature profile flattening is observed in a large helical device [A. Iiyoshi et al. Nucl. Fusion 39, 1245 (1999)] inward shifted plasma with counter-neutral beam injection. To study this phenomenon, heat pulse experiments are performed by on-axis electron cyclotron heating power modulation. A unique feature of heat pulse propagation is observed near the m/n=2/1 rational surface (m, n are the poloidal and toroidal mode numbers, respectively). A simultaneous response of the temperature perturbation on radially separated flux surfaces is shown. The change in the magnetic field topology due to the presence of a magnetic island structure can explain this nonmonotonic heat pulse propagation. The estimated O-point position of the island is located near the m/n=2/1 rational surface.
- OSTI ID:
- 20764535
- Journal Information:
- Physics of Plasmas, Vol. 12, Issue 9; Other Information: DOI: 10.1063/1.2044447; (c) 2005 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
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