Bootstrap current and viscous forces in D-T plasmas

Recently, a Chapman-Enskog-like approach has been developed by treating the kinetic and eight fluid (density n(rvec x,t), temperature T (rvec x,t), momentum m rvec V(rvec x,t) and heat flux rvec q(rvec x,t)) equations consistently. Coulomb collisions of multiple ion species are allowed in a density, momentum and energy conserving collision operator model. Using this formalism, the flux-surface-averaged parallel viscous stress forces left-angle rvec B · rvec ∇ · Πparallel right-angle and left-angle rvec B · rvec ∇ · Θparallel right-angle are calculated by taking a proper untrapped particle flow moment of the bounce-averaged Chapman-Enskog-like version of the drift-kinetic equation. The collisional forces including trapped particle effects are evaluated from the lowest subsidiary order (in ν/ωb, ν = collision frequency, ωb = bounce frequency) kinetic solution. The effects of similar mass multiple ion species on the bootstrap current in a tokamak plasma are presented. 1 ref