ELECTRON MAGNETOHYDRODYNAMICS OF MAGNETIZED, INHOMOGENEOUS PLASMAS

A modified EMHD model is derived that includes the effects of density perturbations and inhomogeneity in a strong magnetic field. Similar to previous EMHD models, the derived equation takes the form of a flux c onservation law for a modified vorticity. The modified vorticity is fr ozen into the current flow. The model unifies whistler and electron gr adient waves and generalizes the nonlinear models for these modes. In 2D, the model again reduces to a set of two coupled equations for the vertical magnetic field and the poloidal flux. The scale length in the equation for the vertical held is modified and a drift term is introd uced there, whereas the equation for the poloidal flux is not modified with respect to previous 2D models. A noncanonical Hamiltonian repres entation for the 2D equations is presented. (C) 1998 Elsevier Science B.V.