Theory of nonlocal transport for small perturbations in a plasma

A system of electron-transport equations for small perturbations in a plasm a, which is suitable for an arbitrary relation between the electron mean fr ee path and the density gradient length, is formulated. Electron-electron c ollisions are treated on the basis of the exact Landau collision integral, making it possible to obtain expressions for the potential elements of the Fourier components of electron fluxes, generalized forces, and all the tran sport coefficients in a plasma with an arbitrary ion charge for the first t ime. The transport coefficients found, viz., the electrical conductivity, t he thermal diffusivity, the thermoelectric coefficient, and the ion convect ion coefficients, permit the quantitative description of an extensive list of small-scale processes in a completely ionized plasma. The suppression of heat transport and the damping of ion-sound waves in a current-free plasma over the entire range of spatial scales of the perturbations from the high -collisionality limit to the collisionless limit are examined as applicatio ns of the theory developed. (C) 1998 American Institute of Physics. [S1063- 7761(98)01011-7].