NONLINEAR DIFFUSION OF THE MAGNETIC-FIELD IN WEAKLY IONIZED PLASMAS

Enhanced nonlinear penetration of the external periodic magnetic field into a weakly ionized plasma is investigated. The penetration is enha nced by the convection of the magnetic field due to the Lorentz force. The nonlinearity leads to the wavelike propagation of the magnetic fi eld or to the nonlinear diffusion similar to the diffusion in porous m edium depending on plasma collisionality. It is shown that the periodi c magnetic field experiences much slower decay inside the plasma compa red to that of the standard skin effect. [S0031-9007(98)07748-5].