Neoclassical momentum transport in an impure rotating tokamak plasma

Journal Article · Sun Jan 15 00:00:00 EST 2006 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.2160518· OSTI ID:20782447

Newton, S; Helander, P ^[1]

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1. H.H. Wills Physics Laboratory, University of Bristol, Royal Fort, Tyndall Avenue, Bristol BS8 1TL (United Kingdom)

It is widely believed that transport barriers in tokamak plasmas are caused by radial electric-field shear, which is governed by angular momentum transport. Turbulence is suppressed in the barrier, and ion thermal transport is comparable to the neoclassical prediction, but experimentally angular momentum transport has remained anomalous. With this motivation, the collisional transport matrix is calculated for a low collisionality plasma with collisional impurity ions. The bulk plasma toroidal rotation velocity is taken to be subsonic, but heavy impurities undergo poloidal redistribution due to the centrifugal force. The impurities give rise to off-diagonal terms in the transport matrix, which cause the plasma to rotate spontaneously. At conventional aspect ratio, poloidal impurity redistribution increases the angular momentum flux by a factor up to {epsilon}{sup -3/2} over previous predictions, making it comparable to the 'banana' regime heat flux. The flux is primarily driven by radial pressure and temperature gradients.

• OSTI ID: 20782447
• Journal Information: Physics of Plasmas, Vol. 13, Issue 1; Other Information: DOI: 10.1063/1.2160518; (c) 2006 American Institute of Physics; 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
ANGULAR MOMENTUM
ASPECT RATIO
BANANA REGIME
CHARGED-PARTICLE TRANSPORT
ELECTRIC FIELDS
ELECTRON COLLISIONS
ELECTRON TEMPERATURE
HEAT FLUX
ION COLLISIONS
ION TEMPERATURE
IONS
NEOCLASSICAL TRANSPORT THEORY
PLASMA
PLASMA CONFINEMENT
PLASMA IMPURITIES
PLASMA PRESSURE
ROTATION
SHEAR
TEMPERATURE GRADIENTS
TOKAMAK DEVICES
TURBULENCE