ELECTRON MAGNETOHYDRODYNAMICS

Electron magnetohydrodynamics is a new branch of theoretical plasma physics with many applications to problems of pulsed plasmas and controlled magnetic fusion, astrophysics and physics of solids. EMH is the multicomponent MHD theory reduced, in the limit of short space and time scales and/or strong fields and high currents, to a form of electron hydrodynamics on a background of immovable ions. It is, in essence, hydrodynamic theory based on quasi-neutrality, the Hall effect and negligible ion motion. Many well-known MHD effects should be revised within the framework of EMH. Diamagnetic properties of quasi-steady plasma based on MHD theory are transformed into paramagnetism. In particular, instead of field diffusion, the result is magnetic field penetration into a conducting medium in the form of a shock wave. The ''classical'' skin problem with an oscillating field as a boundary condition has a nonclassical solution, demonstrating detection instead of the skin effect. Some new classes of instabilities have to be taken into account. These instabilities are faster than those resulting from MHD; hence, they are more effective in magnetic field reconnection and enhanced thermal conductivity. Nontrivial electron streams become possible in thin films, modifying their screen properties. In both Z-pinch and plasma diode, EMH dynamics result in some specific resistance of universal form. EMH effects are responsible for all aspects of plasma switching in the conductivity phase.