Vortex motion of dust particles due to non-conservative ion drag force in a plasma
Vortex motion of the dust in a dusty plasma is shown to result because non-parallelism of the ion density gradient and the gradient of the magnitude of the ion ambipolar velocity cause the ion drag force on dust grains to be non-conservative. Dust grain poloidal vortices consistent with the model predictions are experimentally observed, and the vortices change character with imposed changes in the ion temperature profile as predicted. For a certain ion temperature profile, two adjacent co-rotating poloidal vortices have a well-defined X-point analogous to the X-point in magnetic reconnection.
© 2016 AIP Publishing LLC. Received 15 December 2015; accepted 29 January 2016; published online 12 February 2016. This material was based upon work supported by the U.S. Department of Energy Office of Science, Office of Fusion Energy Sciences under Award No. DE-SC0010471.
Published - 1.4941973.pdf