Testing neoclassical and turbulent effects on poloidal rotation in the core of DIII-D

Journal Article · Tue Jul 15 04:00:00 EDT 2014 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4887296· OSTI ID:22304088

Chrystal, C. ^[1]; Burrell, K. H.; Staebler, G. M.; Kinsey, J. E.; Lao, L. L.; Grassie, J. S. de ^[2]; Grierson, B. A.; Solomon, W. M.; Wang, W. X. ^[3]; Rhodes, T. L.; Schmitz, L. ^[4]; Mordijck, S. ^[5]; Meneghini, O. ^[6]

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1. University of California San Diego, 9500 Gilman Dr., La Jolla, California 92093-0417 (United States)
2. General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States)
3. Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543-0451 (United States)
4. University of California Los Angeles, P.O. Box 957099, Los Angeles, California 90095-7099 (United States)
5. College of William and Mary, P.O. Box 8795, Williamsburg, Virginia 23187-8795 (United States)
6. Oak Ridge Associated Universities, 1299 Bethel Valley Rd, Bldg SC-200, Oak Ridge, Tennessee 37830 (United States)

Experimental tests of ion poloidal rotation theories have been performed on DIII-D using a novel impurity poloidal rotation diagnostic. These tests show significant disagreements with theoretical predictions in various conditions, including L-mode plasmas with internal transport barriers (ITB), H-mode plasmas, and QH-mode plasmas. The theories tested include standard neoclassical theory, turbulence driven Reynolds stress, and fast-ion friction on the thermal ions. Poloidal rotation is observed to spin up at the formation of an ITB and makes a significant contribution to the measurement of the E{sup →}×B{sup →} shear that forms the ITB. In ITB cases, neoclassical theory agrees quantitatively with the experimental measurements only in the steep gradient region. Significant quantitative disagreement with neoclassical predictions is seen in the cores of ITB, QH-, and H-mode plasmas, demonstrating that neoclassical theory is an incomplete description of poloidal rotation. The addition of turbulence driven Reynolds stress does not remedy this disagreement; linear stability calculations and Doppler backscattering measurements show that disagreement increases as turbulence levels decline. Furthermore, the effect of fast-ion friction, by itself, does not lead to improved agreement; in QH-mode plasmas, neoclassical predictions are closest to experimental results in plasmas with the largest fast ion friction. Predictions from a new model that combines all three effects show somewhat better agreement in the H-mode case, but discrepancies well outside the experimental error bars remain.

• OSTI ID: 22304088
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 7 Vol. 21; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BACKSCATTERING
CHARGED-PARTICLE TRANSPORT
DOUBLET-3 DEVICE
H-MODE PLASMA CONFINEMENT
IONS
L-MODE PLASMA CONFINEMENT
NEOCLASSICAL TRANSPORT THEORY
PLASMA
REYNOLDS NUMBER