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Diocotron and Kelvin mode damping from a flux through the critical layer
A A Kabantsev1, C Y Chim1, T M O'Neil1
1Department of Physics, University of California at San Diego, La Jolla, California 92093, USA.
Abstract:
Experiments and theory characterize a novel type of spatial Landau damping, caused by a flux of particles through the wave or rotation resonance (critical) layer. Pure electron plasma experiments demonstrate that a steady flux of particles causes algebraic damping of diocotron mode amplitudes for azimuthal modes m = 1 and m = 2, and a simple model of dynamics in the nonlinear cat's eye clarifies the observations. This flux-driven algebraic damping is related to, but distinct from, the exponential decay characteristic of Landau damping. This flux-driven damping applies also to Kelvin waves on 2D vortices, and so may be broadly relevant to plasmas and geophysical flows.
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