Comparison of poloidal velocity measurements to neoclassical theory on the National Spherical Torus Experiment

Journal Article · Sun Aug 15 04:00:00 EDT 2010 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3478571· OSTI ID:21432226

Bell, R E; Andre, R; Kaye, S M; Kolesnikov, R A; LeBlanc, B P; Rewoldt, G; Wang, W X ^[1]; Sabbagh, S A ^[2]

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1. Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)
2. Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States)

Knowledge of poloidal velocity is necessary for the determination of the radial electric field, which along with its gradient is linked to turbulence suppression and transport barrier formation. Recent measurements of poloidal flow on conventional tokamaks have been reported to be an order of magnitude larger than expected from neoclassical theory. In contrast, poloidal velocity measurements on the NSTX spherical torus [Kaye et al., Phys. Plasmas 8, 1977 (2001)] are near or below neoclassical estimates. A novel charge exchange recombination spectroscopy diagnostic is used, which features active and passive sets of up/down symmetric views to produce line-integrated poloidal velocity measurements that do not need atomic physics corrections. Inversions are used to extract local profiles from line-integrated active and background measurements. Poloidal velocity measurements are compared with neoclassical values computed with the codes NCLASS[Houlberg et al., Phys. Plasmas 4, 3230 (1997)] and GTC-NEO[Wang et al., Phys. Plasmas 13, 082501 (2006)].

• OSTI ID: 21432226
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 8 Vol. 17; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
CHARGE EXCHANGE
CHARGED-PARTICLE TRANSPORT THEORY
CLOSED PLASMA DEVICES
ELECTRIC FIELDS
NEOCLASSICAL TRANSPORT THEORY
NSTX DEVICE
PLASMA
PLASMA DIAGNOSTICS
PLASMA SIMULATION
RECOMBINATION
SIMULATION
SPECTROSCOPY
SPHEROMAK DEVICES
THERMONUCLEAR DEVICES
TOKAMAK DEVICES
TRANSPORT THEORY
TURBULENCE
VELOCITY