Convection in a cylindrical plasma column with a free boundary

Abstract

It is shown that in a current-carrying cylindrical plasma with a free boundary, resistivity and thermal conductivity can lead to large-scale steady convection. Convection can take place for any azimuthal wave number m, provided that |k| α ≫ 1 or |k| α ≪ 1, where k is the longitudinal wave number and α is the radius of the plasma column. Otherwise, convection occurs only for large m values. The states that can trigger large-scale stationary convection are incompressible and satisfy the heat conduction equation for arbitrary finite adiabaticity coefficient, γ, provided that η/κ = 8π/3, where η is the resistivity and κ is the thermal conductivity. The convection cells are helically twisted tubes, and the number of convection cells is equal to 2m. The situation is very similar to the case when the plasma column is limited by perfectly conducting walls. © 1992 American Institute of Physics.