A closure scheme for modeling rf modifications to the fluid equations

A procedure to include the effects of externally applied rf sources in a comprehensive fluid model is outlined. The fluid equations are derived from moments of a kinetic equation that includes the effects of an rf source. In general, this source produces additional terms in each of the fluid equations. A complete derivation requires the specification of the closure moments; calculations for the stress tensors and heat fluxes that are altered by the presence of the rf are required. By treating the rf induced modification as producing a small distortion away from the background Maxwellian distribution function, a procedure for calculating the closure moments can be formulated. Using a Chapman–Enskog-like procedure, a kinetic equation for the kinetic distortion can be derived that includes the rf-induced contributions to the fluid equations as sources.