Tokamak turbulence in self-regulated differentially rotating flow and L-H transition dynamics

Conference · Sun Nov 01 04:00:00 EST 1992

OSTI ID:10181971

Terry, P W ^[1]; Diamond, P H ^[2]; Carreras, B A; Sidikman, K ^[3]

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1. Wisconsin Univ., Madison, WI (United States). Dept. of Physics
2. California Univ., San Diego, La Jolla, CA (United States). Dept. of Physics
3. Oak Ridge National Lab., TN (United States)

An analytical study of turbulence in the presence of turbulently generated differentially rotating flow is presented as a paradigm for fluctuation dynamics in L- and H-mode plasmas. Using a drift wave model, the role of both flow shear and flow curvature (second radial derivative of the poloidal ExB flow) is detailed in linear and saturated turbulence phases. In the strong turbulence saturated state, finite amplitude-induced modification of the fluctuation structure near low order rational surfaces strongly inhibits flow shear suppression. Suppression by curvature is not diminished, but it occurs through a frequency shift. A description of L-H mode transition dynamics based on the self-consistent linking of turbulence suppression by differentially rotating flow and generation of flow by turbulent momentum transport is presented. In this model, rising edge temperature triggers a transition characterized by spontaneous generation of differentially rotating flow and decreasing turbulence intensity.

• Research Organization: Oak Ridge National Lab., TN (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC05-84OR21400; FG02-89ER53291
• OSTI ID: 10181971
• Report Number(s): CONF-920142--2; ON: DE93000443
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700310
700330
700370
FLUCTUATIONS
H-MODE PLASMA CONFINEMENT
NONLINEAR PROBLEMS
PLASMA CONFINEMENT
PLASMA FLUID AND MHD PROPERTIES
PLASMA KINETICS, TRANSPORT, AND IMPURITIES
ROTATING PLASMA
TOKAMAK DEVICES
TURBULENT FLOW