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Turbulence Dynamics with the Coupling of Density Gradient and Parallel Velocity Gradient in the Edge Plasmas
Author(s) -
Kosuga Y.,
Itoh S.I.,
Itoh K.
Publication year - 2016
Publication title -
contributions to plasma physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.531
H-Index - 47
eISSN - 1521-3986
pISSN - 0863-1042
DOI - 10.1002/ctpp.201610047
Subject(s) - physics , turbulence , helicity , instability , excited state , plasma , mechanics , nonlinear system , zonal flow (plasma) , coupling (piping) , mode coupling , shear flow , density gradient , classical mechanics , atomic physics , tokamak , quantum mechanics , materials science , metallurgy
Theory of parallel shear flow driven instability (PSFI) and its impact on turbulence dynamics and transport are presented. The mode is linearly unstable when the parallel flow shear exceeds a critical value. The quasilinear particle flux contains both outward and inward components. Nonlinear dynamics is formulated in terms of hydrodynamic helicity balance. The result implies that once excited, PSFI with helicity may spread from the excited region to stable regions. Implication for turbulence in scrape off layer plasmas is discussed. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)