Anomalous Diffusion Arising from Drift Instability in a Cylindrical Plasma

Abstract

A cylinder of collision-free plasma in a strong, uniform magnetic field parallel to its axis is studied theoretically. A plasma of cylindrical symmetry in equilibrium is assumed to have a current due to the electron velocity distribution of a shifted Maxwellian type. Drift instability is discussed for the density profile n(r)=N₀(1−r²⁄a²), N₀ being the density on the axis. The drift waves are shown to grow to form a nonlinear equilibrium spectrum and to generate an anomalous diffusion, whose coefficient is about one-tenth of Bohm’s in magnitude.