ABSTRACT
Since Eqs. (2.12) and (2.16) which describe the energy transport are rather cumbersome, these processes in plasmas are, generally speaking, far more diverse and complicated than the transport of charged particles. From die preceding Chapters it follows that a great number of problems exists, in which die particle transport can be analyzed at the uniform or prescribed partial temperatures. In contrast, the particle fluxes which accompany the energy transport, are, as a rule, considerable. Also significant is the redistribution of the partial densities in the course of relaxation of the temperature inhomogeneity. Accordingly, the problems of the influence of the self-consistent electromagnetic fields on the energy transport are intricate, and even rough attempts to classify the mechanisms of this influence, especially in magnetic field, are practically absent. The situation is simplified by the fact that in the weakly ionized plasmas the main part of the internal energy is connected with the neutral component, and the balance of the neutral temperature TN can be analyzed in the traditional manner. The energy exchange between the heavy particles (neutrals and ions) occurs practically during die collision time vw'‘. It makes it senseless to distinguish between TN and the partial ion temperatures. On the other hand, since in most of the applications we meet non-equilibrium plasmas, the situations when the electron temperature (mean energy) considerably deviates from Tn, are rather typical. Consequently, the most interesting problem concerns the partial electron energy transport These processes play an important role if die energy sources and sinks are spatially non-uniform, with the characteristic scale L which is small with respect to the electron energy relaxation length A,(eE), Eq. (2.20). In this case the electron thermal conductivity dominates. During the energy relaxation time (btNvt/^-Sttveiy l
the electron thermal conductivity levels off the electron temperature Te over the scale )S*\ In the opposite case L » X ^ the local electron energy balance prevails, and the energy transport processes are unimportant.
