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Title: The impact of pedestal turbulence and electron inertia on edge-localized-mode crashes

We demonstrate that the occurrence of Edge-Localized-Modes (ELM) crashes does not depend only on the linear peeling-ballooning threshold, but also relies on nonlinear processes. Wave-wave interaction constrains the growth time of a mode, thus inducing a shift in the criterion for triggering an ELM crash. An ELM crash requires the P-B growth rate to exceed a critical value γ>γ{sub c}, where γ{sub c} is set by 1/τ{sup ¯}{sub c}, and τ{sup ¯}{sub c} is the averaged mode phase coherence time. For 0<γ<γ{sub c}, P-B turbulence develops but drives enhanced turbulent transport. We also show that electron inertia dramatically changes the instability threshold when density is low. However, P-B turbulence alone cannot generate enough current transport to allow fast reconnection during an ELM crash.
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [2]
  1. FSC and State Key Lab of Nuclear Physics and Technology, Department of Physics, Peking University, Beijing 100871 (China)
  2. (United States)
  3. Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)
  4. WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon (Korea, Republic of)
Publication Date:
OSTI Identifier:
22252923
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 21; Journal Issue: 5; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; BALLOONING INSTABILITY; EDGE LOCALIZED MODES; MOMENT OF INERTIA; NONLINEAR PROBLEMS