File Download

There are no files associated with this item.

  • Find it @ UNIST can give you direct access to the published full text of this article. (UNISTARs only)
Related Researcher

박현거

Park, Hyeon Keo
Read More

Views & Downloads

Detailed Information

Cited time in webofscience Cited time in scopus
Metadata Downloads

Distinct stages of radio frequency emission at the onset of pedestal collapse in KSTAR H-mode plasmas

Author(s)
Kim, M. H.Thatipamula, S. G.Lee, J. E.Choi, M. J.Park, Hyeon KeoAkiyama, T.Yun, G. S.
Issued Date
2018-09
DOI
10.1088/1741-4326/aad05a
URI
https://scholarworks.unist.ac.kr/handle/201301/24703
Fulltext
http://iopscience.iop.org/article/10.1088/1741-4326/aad05a/meta
Citation
NUCLEAR FUSION, v.58, no.9, pp.096034
Abstract
Using a high-speed and broadband radio frequency (RF) (0.1-1 GHz) spectrum analyzer developed on the KSTAR tokamak, it is found that several distinct stages of RF emission appear at the pedestal collapse in high confinement discharges. Comparison with 2D electron cyclotron emission (ECE) images has revealed that each stage is related to the instantaneous condition at the outboard mid-plane edge. First, high-harmonic ion cyclotron emissions (ICE) are intensified with the appearance of a non-modal filamentary perturbation in the edge within several tens of microseconds before the collapse. Then, the RF emission becomes broad toward high-frequency range (<500 MHz) at the burst onset of the non-modal filament. During the pedestal collapse initiated by the filament burst, rapid chirping (1-3 mu s) appear with additional filament bursts. The strong correlation between the RF spectra and the perturbation structure provides important clues on the stability of edge-localized modes and on the ion dynamics in the plasma boundary.
Publisher
IOP PUBLISHING LTD
ISSN
0029-5515
Keyword (Author)
radio frequency burstedge-localized modeion cyclotron harmonic wavesRF spectroscopyelectron cyclotron emission imaging
Keyword
ELMS

qrcode

Items in Repository are protected by copyright, with all rights reserved, unless otherwise indicated.