title: Observation of plasma toroidal-momentum dissipation by neoclassical toroidal viscosity.
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.
authors.affiliation: Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027, USA.
authors.forename: W
authors.initials: W
authors.lastname: Zhu
authors.forename: S A
authors.initials: SA
authors.lastname: Sabbagh
authors.forename: R E
authors.initials: RE
authors.lastname: Bell
authors.forename: J M
authors.initials: JM
authors.lastname: Bialek
authors.forename: M G
authors.initials: MG
authors.lastname: Bell
authors.forename: B P
authors.initials: BP
authors.lastname: LeBlanc
authors.forename: S M
authors.initials: SM
authors.lastname: Kaye
authors.forename: F M
authors.initials: FM
authors.lastname: Levinton
authors.forename: J E
authors.initials: JE
authors.lastname: Menard
authors.forename: K C
authors.initials: KC
authors.lastname: Shaing
authors.forename: A C
authors.initials: AC
authors.lastname: Sontag
authors.forename: H
authors.initials: H
authors.lastname: Yuh