Simulations of drift resistive ballooning L-mode turbulence in the edge plasma of the DIII-D tokamak

Journal Article · Wed May 15 00:00:00 EDT 2013 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4804638· OSTI ID:22228071

Cohen, B. I.; Umansky, M. V.; Nevins, W. M.; Makowski, M. A. ^[1]; Boedo, J. A.; Rudakov, D. L. ^[2]; McKee, G. R.; Yan, Z. ^[3]; Groebner, R. J. ^[4]

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1. Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)
2. University of California, San Diego, San Diego, California 92093 (United States)
3. University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)
4. General Atomics, P.O. Box 85608, San Diego, California 92186 (United States)

Results from simulations of electromagnetic drift-resistive ballooning turbulence for tokamak edge turbulence in realistic single-null geometry are reported. The calculations are undertaken with the BOUT three-dimensional fluid code that solves Braginskii-based fluid equations [X. Q. Xu and R. H. Cohen, Contrib. Plasma Phys. 36, 158 (1998)]. The simulation setup models L-mode edge plasma parameters in the actual magnetic geometry of the DIII-D tokamak [J. L. Luxon et al., Fusion Sci. Technol. 48, 807 (2002)]. The computations track the development of drift-resistive ballooning turbulence in the edge region to saturation. Fluctuation amplitudes, fluctuation spectra, and particle and thermal fluxes are compared to experimental data near the outer midplane from Langmuir probe and beam-emission-spectroscopy for a few well-characterized L-mode discharges in DIII-D. The simulations are comprised of a suite of runs in which the physics model is varied to include more fluid fields and physics terms. The simulations yield results for fluctuation amplitudes, correlation lengths, particle and energy fluxes, and diffusivities that agree with measurements within an order of magnitude and within factors of 2 or better for some of the data. The agreement of the simulations with the experimental measurements varies with respect to including more physics in the model equations within the suite of models investigated. The simulations show stabilizing effects of sheared E × B poloidal rotation (imposed zonal flow) and of lower edge electron temperature and density.

• OSTI ID: 22228071
• 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

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BALLOONING INSTABILITY
BOUNDARY LAYERS
CALCULATION METHODS
COMPARATIVE EVALUATIONS
CORRELATIONS
DOUBLET-3 DEVICE
ELECTRIC DISCHARGES
ELECTROMAGNETIC RADIATION
ELECTRON TEMPERATURE
EMISSION SPECTROSCOPY
FLUCTUATIONS
ION TEMPERATURE
LANGMUIR PROBE
L-MODE PLASMA CONFINEMENT
MAGNETOHYDRODYNAMICS
PLASMA DENSITY
PLASMA SIMULATION
SHEAR
THREE-DIMENSIONAL CALCULATIONS
TURBULENCE