Neoclassical parallel flow calculation in the presence of external parallel momentum sources in Heliotron J

Journal Article · Tue Mar 15 00:00:00 EDT 2016 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4944913· OSTI ID:22599050

Nishioka, K.; Nakamura, Y. ^[1]; Nishimura, S. ^[2]; Lee, H. Y. ^[3]; Kobayashi, S.; Mizuuchi, T.; Nagasaki, K.; Okada, H.; Minami, T.; Kado, S.; Yamamoto, S.; Ohshima, S.; Konoshima, S.; Sano, F. ^[4]

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1. Graduate School of Energy Science, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan)
2. National Institute for Fusion Science, 322-6 Oroshi-cho, Toki, Gifu 509-5292 (Japan)
3. Korea Advanced Institute of Science and Technology, Daejeon 305-701 (Korea, Republic of)
4. Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan)

A moment approach to calculate neoclassical transport in non-axisymmetric torus plasmas composed of multiple ion species is extended to include the external parallel momentum sources due to unbalanced tangential neutral beam injections (NBIs). The momentum sources that are included in the parallel momentum balance are calculated from the collision operators of background particles with fast ions. This method is applied for the clarification of the physical mechanism of the neoclassical parallel ion flows and the multi-ion species effect on them in Heliotron J NBI plasmas. It is found that parallel ion flow can be determined by the balance between the parallel viscosity and the external momentum source in the region where the external source is much larger than the thermodynamic force driven source in the collisional plasmas. This is because the friction between C{sup 6+} and D{sup +} prevents a large difference between C{sup 6+} and D{sup +} flow velocities in such plasmas. The C{sup 6+} flow velocities, which are measured by the charge exchange recombination spectroscopy system, are numerically evaluated with this method. It is shown that the experimentally measured C{sup 6+} impurity flow velocities do not contradict clearly with the neoclassical estimations, and the dependence of parallel flow velocities on the magnetic field ripples is consistent in both results.

• OSTI ID: 22599050
• Journal Information: Physics of Plasmas, Vol. 23, Issue 3; Other Information: (c) 2016 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
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AXIAL SYMMETRY
BALANCES
BEAM INJECTION
CHARGE EXCHANGE
COLLISIONAL PLASMA
FLOW RATE
FRICTION
HELIOTRON
IMPURITIES
IONS
MAGNETIC FIELD RIPPLES
MAGNETIC FIELDS
NEOCLASSICAL TRANSPORT THEORY
PARTICLES
VELOCITY
VISCOSITY