Global gyrokinetic simulations of the H-mode tokamak edge pedestal
- Department of Physics, University of Colorado, Boulder, Colorado 80309 (United States)
- General Atomics, Post Office Box 85068, San Diego, California 92186 (United States)
- University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)
- Tech-X Corporation, 5621 Arapahoe Ave., Boulder, Colorado 80305 (United States)
Global gyrokinetic simulations of DIII-D H-mode edge pedestal show two types of instabilities may exist approaching the onset of edge localized modes: an intermediate-n, high frequency mode which we identify as the “kinetic peeling ballooning mode (KPBM),” and a high-n, low frequency mode. Our previous study [W. Wan et al., Phys. Rev. Lett. 109, 185004 (2012)] has shown that when the safety factor profile is flattened around the steep pressure gradient region, the high-n mode is clearly kinetic ballooning mode and becomes the dominant instability. Otherwise, the KPBM dominates. Here, the properties of the two instabilities are studied by varying the density and temperature profiles. It is found that the KPBM is destabilized by density and ion temperature gradient, and the high-n mode is mostly destabilized by electron temperature gradient. Nonlinear simulations with the KPBM saturate at high levels. The equilibrium radial electric field (E{sub r}) reduces the transport. The effect of the parallel equilibrium current is found to be weak.
- OSTI ID:
- 22228067
- Journal Information:
- Physics of Plasmas, Vol. 20, Issue 5; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BALLOONING INSTABILITY
BOUNDARY LAYERS
DOUBLET-3 DEVICE
EDGE LOCALIZED MODES
ELECTRIC CURRENTS
ELECTRIC FIELDS
ELECTRON TEMPERATURE
H-MODE PLASMA CONFINEMENT
ION TEMPERATURE
NONLINEAR PROBLEMS
PLASMA DENSITY
PLASMA PRESSURE
PLASMA SIMULATION
PRESSURE GRADIENTS
TEMPERATURE GRADIENTS