Two-dimensional imaging of edge-localized modes in KSTAR plasmas unperturbed and perturbed by n=1 external magnetic fields
- Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of)
- University of California at Davis, Davis, California 95616 (United States)
- Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)
- FOM-Institute for Plasma Physics Rijnhuizen, 3430 BE Nieuwegein (Netherlands)
- National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of)
The temporal evolution of edge-localized modes (ELMs) has been studied using a 2-D electron cyclotron emission imaging system in the KSTAR tokamak. The ELMs are observed to evolve in three distinctive stages: the initial linear growth of multiple filamentary structures having a net poloidal rotation, the interim state of regularly spaced saturated filaments, and the final crash through a short transient phase characterized by abrupt changes in the relative amplitudes and distance among filaments. The crash phase, typically consisted of multiple bursts of a single filament, involves a complex dynamics, poloidal elongation of the bursting filament, development of a fingerlike bulge, and fast localized burst through the finger. Substantial alterations of the ELM dynamics, such as mode number, poloidal rotation, and crash time scale, have been observed under external magnetic perturbations with the toroidal mode number n= 1.
- OSTI ID:
- 22072392
- Journal Information:
- Physics of Plasmas, Vol. 19, Issue 5; Other Information: (c) 2012 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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