title: Momentum-transport studies in high E x B shear plasmas in the National Spherical Torus Experiment.
abstract: Experiments have been conducted at the National Sperical Torus Experiment (NSTX) to study both steady state and perturbative momentum transport. These studies are unique in their parameter space under investigation, where the low aspect ratio of NSTX results in rapid plasma rotation with ExB shearing rates high enough to suppress low-k turbulence. In some cases, the ratio of momentum to energy confinement time is found to exceed five. Momentum pinch velocities of order 10-40 m/s are inferred from the measured angular momentum flux evolution after nonresonant magnetic perturbations are applied to brake the plasma.
authors.affiliation: Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543, USA. wsolomon@pppl.gov
authors.forename: W M
authors.initials: WM
authors.lastname: Solomon
authors.forename: S M
authors.initials: SM
authors.lastname: Kaye
authors.forename: R E
authors.initials: RE
authors.lastname: Bell
authors.forename: B P
authors.initials: BP
authors.lastname: Leblanc
authors.forename: J E
authors.initials: JE
authors.lastname: Menard
authors.forename: G
authors.initials: G
authors.lastname: Rewoldt
authors.forename: W
authors.initials: W
authors.lastname: Wang
authors.forename: F M
authors.initials: FM
authors.lastname: Levinton
authors.forename: H
authors.initials: H
authors.lastname: Yuh
authors.forename: S A
authors.initials: SA
authors.lastname: Sabbagh