Steady-state dynamo and current drive in a nonuniform bounded plasma

Technical Report · Fri Mar 01 00:00:00 EST 1991

OSTI ID:5727668

Mett, R R; Taylor, J B

Current drive due to helicity injection and dynamo effect are examined in an inhomogeneous bounded plasma. Averaged over a magnetic surface, there is in general no dynamo effect independent of resistivity -- contrary to the results found previously for an unbounded plasma. The dynamo field is calculated explicitly for an incompressible visco-resistive fluid in the plane-slab model. In accord with our general conclusion, outside the Alfven resonant layer it is proportional to the resistivity. Within the resonant layer there is a contribution which is enhanced, relative to its value outside the layer, by a factor ({omega}a{sup 2}/({eta} + {nu})), where {omega} is the wave frequency, a the plasma radius, {eta} the magnetic diffusivity, and {nu} the kinematic viscosity. However, this contribution vanishes when integrated across the layer. The average field in the layer is enhanced by factor ({omega}a{sup 2}/({eta} + {nu})){sup 2/3} and is proportional to the shear in the magnetic field and the cube root of the gradient of the Alfven speed. These results are interpreted in terms of helicity balance, and reconciled with the infinite medium calculations. 15 refs.

• Research Organization: Texas Univ., Austin, TX (USA). Inst. for Fusion Studies
• Sponsoring Organization: USDOE; USDOE, Washington, DC (USA)
• DOE Contract Number: FG05-80ET53088
• OSTI ID: 5727668
• Report Number(s): DOE/ET/53088-490; IFSR-490; ON: DE91014865
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
INHOMOGENEOUS PLASMA
NON-INDUCTIVE CURRENT DRIVE
ALFVEN WAVES
FLOW MODELS
FLUCTUATIONS
HELICITY
INCOMPRESSIBLE FLOW
MAGNETIC FIELDS
MAGNETIC SURFACES
FLUID FLOW
HYDROMAGNETIC WAVES
MAGNETIC FIELD CONFIGURATIONS
MATHEMATICAL MODELS
PARTICLE PROPERTIES
PLASMA
VARIATIONS
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