Open AccessEffect of Ambipolar Plasma Flow on the Penetration of Resonant Magnetic Perturbations in a Quasi-axisymmetric Stellarator
Author(s) -
A. Reiman,
M. C. Zarnstorff,
D. R. Mikkelsen,
L.W. Owen,
H. Mynick,
S. R. Hudson,
D. Monticello
Publication year - 2005
Language(s) - English
Resource type - Reports
DOI - 10.2172/839129
Subject(s) - ambipolar diffusion , stellarator , physics , plasma , magnetic field , rotational symmetry , resonant magnetic perturbations , toroid , perturbation (astronomy) , mechanics , magnetohydrodynamics , electromagnetic shielding , atomic physics , computational physics , nuclear physics , quantum mechanics
A reference equilibrium for the U.S. National Compact Stellarator Experiment is predicted to be sufficiently close to quasi-symmetry to allow the plasma to flow in the toroidal direction with little viscous damping, yet to have sufficiently large deviations from quasi-symmetry that nonambipolarity significantly affects the physics of the shielding of resonant magnetic perturbations by plasma flow. The unperturbed velocity profile is modified by the presence of an ambipolar potential, which produces a broad velocity profile. In the presence of a resonant magnetic field perturbation, nonambipolar transport produces a radial current, and the resulting j x B force resists departures from the ambipolar velocity and enhances the shielding