Two-dimensional electron-magnetohydrodynamic instabilities

The linear dispersion relation and the spatial structure of high frequency instabilities, with a mixed tearing-bending character is studied. These instabilities are driven by the electron velocity gradient in a collisionless electron plasma moving against a background of immobile neutralizing ions in an inhomogeneous magnetic field. As the angle between the perturbations and the magnetic field lines is varied, perturbations change from the tearing type (parallel propagation) to the bending type (perpendicular propagation). (C) 1999 American Institute of Physics. [S1070-664X(99)01406-8].