Generalization of collisional fluid theory to long mean-free-path and relativistic motion

The influence of collisions on a magnetized plasma at arbitrary collisionality is modeled by fluid equations that include the self-consistent moments of the collision operator. A key feature of the derivation is its basis in Lorentz-invariant equations, using the most general form of the energy-momentum tensor in a magnetized plasma. The collisional limit of the resulting description is shown to agree qualitatively with well-known short mean-free-path equations. In particular it reproduces exactly the correct symmetry of the transport matrix. Previously the long mean-free-path limit has been shown to reproduce collisionless physics more accurately than other collisionless fluid models. (C) 2002 American Institute of Physics.