title: Nonlinear Interaction of Edge-Localized Modes and Turbulent Eddies in Toroidal Plasma under n=1 Magnetic Perturbation.
abstract: The effect of static n=1 resonant magnetic perturbation (RMP) on the spatial structure and temporal dynamics of edge-localized modes (ELMs) and edge turbulence in tokamak plasma has been investigated. Two-dimensional images measured by a millimeter-wave camera on the KSTAR tokamak revealed that the coherent filamentary modes (i.e., ELMs) are still present in the edge region when the usual large scale collapse of the edge confinement, i.e., the ELM crash, is completely suppressed by n=1 RMP. Cross-correlation analyses on the 2D images show that (1) the RMP enhances turbulent fluctuations in the edge toward the ELM-crash-suppression phase, (2) the induced turbulence has a clear dispersion relation for wide ranges of wave number and frequency, and (3) the turbulence involves a net radially outward energy transport. Nonlinear interactions of the turbulent eddies with the coexisting ELMs are clearly observed by bispectral analysis, which implies that the exchange of energy between them may be the key to the prevention of large scale crashes.
authors: Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea.
authors: Jaehyun
authors: J
authors: Lee
authors: Pohang University of Science and Technology, Pohang 37673, Republic of Korea.
authors: Gunsu S
authors: GS
authors: Yun
authors: National Fusion Research Institute, Daejeon 34133, Republic of Korea.
authors: Minjun J
authors: MJ
authors: Choi
authors: National Fusion Research Institute, Daejeon 34133, Republic of Korea.
authors: Jae-Min
authors: JM
authors: Kwon
authors: National Fusion Research Institute, Daejeon 34133, Republic of Korea.
authors: Young-Mu
authors: YM
authors: Jeon
authors: Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea.
authors: Woochang
authors: W
authors: Lee
authors: University of California at Davis, Davis, California 95616, USA.
authors: Neville C
authors: NC
authors: Luhmann
authors: Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea.|National Fusion Research Institute, Daejeon 34133, Republic of Korea.
authors: Hyeon K
authors: HK
authors: Park