Observation of plasma toroidal-momentum dissipation by neoclassical toroidal viscosity.

Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027, USA.
Physical Review Letters (Impact Factor: 7.73). 07/2006; 96(22):225002. DOI: 10.1103/PhysRevLett.96.225002
Source: PubMed

ABSTRACT Dissipation of plasma toroidal angular momentum is observed in the National Spherical Torus Experiment due to applied nonaxisymmetric magnetic fields and their plasma-induced increase by resonant field amplification and resistive wall mode destabilization. The measured decrease of the plasma toroidal angular momentum profile is compared to calculations of nonresonant drag torque based on the theory of neoclassical toroidal viscosity. Quantitative agreement between experiment and theory is found when the effect of toroidally trapped particles is included.

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