The Plasma Equations

Abstract

In contrast to the preceding chapters, which considered the microscopic behavior of particles, this chapter will deal with the motion of the various plasma components (electrons, ions, neutrals) on a macroscopic scale under the influence of external as well as internal forces. Since this treatment will be restricted to thermal plasmas, which can be conveniently generated by electric arcs or high-power RF discharges, temperature is the most important parameter. Thus, the derivation of the plasma equations (for current, momentum, mass, and heat flow) will be based on thermodynamics and irreversible thermodynamics. This particular approach provides a straightforward survey of the various effects that govern the behavior of such plasmas, although it leaves the absolute values of the coefficients (e.g., the friction coefficient of the diffusion coefficient) open. These values will be derived from kinetic theory.