Diffusion of a Plasma with a Small Dielectric Constant in the dc Octopole

Abstract

A new type of diffusion is observed. The observed dependences and magnitude of the diffusion coefficient are consistent with the theory of "classical" diffusion due to thermal equilibrium fluctuations for closed line configurations. The experimental results with the toroidal field are essentially the same as those without the toroidal field. The shear may be ineffective in modifying the diffusion rate because of the short perpendicular diffusion damping time compared with the parallel phase mixing time.