Experimental observation of a tripolar vortex in a plasma
Okamoto, A × Hara, K Nagaoka, K Yoshimura, S Vranjes, Jovo Kono, M Tanaka, MY #
Amer inst physics
Physics of plasmas vol:10 issue:6 pages:2211-2216
A tripolar vortex, three aligned vortices with alternate signs of polarity of rotation, has been observed in a plasma for the first time. The tripolar vortex always appears with a deep density depression in the neutral particles, and the rotation direction of each vortex is opposite to that of the E x B rotation due to the ambipolar electric field. It is shown that a net momentum transfer during the charge-exchange interaction produces an effective force acting on the ions. The present experiment shows that this effective force may dominate the ambipolar-electric field and drive the anti-E x B vortical motion of ions. (C) 2003 American Institute of Physics.