Conditions for up-down asymmetry in the core of tokamak equilibria

Abstract

A local magnetic equilibrium solution is sought around the magnetic axis in order to identify the key parameters defining the magnetic-surface's up-down asymmetry in the core of tokamak plasmas. The asymmetry is found to be determined essentially by the ratio of the toroidal current density flowing on axis to the fraction of the external field's odd perturbation that manages to propagate from the plasma boundary into the core. The predictions are tested and illustrated first with an analytical Solovev equilibrium and then using experimentally relevant numerical equilibria. Hollow current-density distributions, and hence reverse magnetic shear, are seen to be crucial to bring into the core asymmetry values that are usually found only near the plasma edge.

6 pages, 2 figures, submitted for publication

References in corpus (1)

• Intrinsic momentum transport in up-down asymmetric tokamaks

Cited by in corpus (6)

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• Local up-down asymmetrically shaped equilibrium model for tokamak plasmas
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• Turbulent momentum transport due to the beating between different tokamak flux surface shaping effects
• Up-down asymmetric tokamaks
• Effect of the Shafranov shift and the gradient of $\beta$ on intrinsic momentum transport in up-down asymmetric tokamaks