Plasma Physics and Magnetohydrodynamics

Abstract

In this chapter we take up wave propagation in an electromagnetically conducting fluid which we call a plasma. Conduction occurs when there are free electrons or other charged particles (ions) that can move under the action of applied forces. We need a fluid (liquid or gas) for the mass motion of these charged particles, since in a solid the electrons are bound and thus suffer a smaller motion on a macro scale so that there is practically no mass motion. However, in a solid the electrons can move on an atomic scale within the lattice structure; thus there are dynamic effects, such as the Hall effect, which are observed when external fields are applied. These fields cause stresses to occur in the lattice structure. We do not consider the effect of external fields on the electromagnetic properties of solids, but we concentrate on fluids or plasmas. For a plasma, the effect of an external field on electrons and other charged particles is to produce bulk motion of the fluid and other dynamic effects associated with the reaction of plasmas to oscillating electromagnetic fields. We are therefore concerned with the fluid dynamics of a fluid medium containing charged particles. The equations of fluid dynamics must contain the electromagnetic properties of the fluid as expressed by Maxwell’s equations.