Resonant collisional transport
Abstract
A variational principle is derived, based on a minimum of entropy production rate. It allows recovering most results of collisional transport boosted by resonances. This note starts with a general introduction to collisional transport enhancement by resonant processes, dubbed as "banana-plateau regime" in neoclassical theory. It then explains how a general variational principle can be constructed, which describes accurately collisional transport processes. This methodology is then used in an axisymmetric tokamak for a single ion species. Usual results for the ion poloidal velocity and heat conductivity are recovered. Electron physics is then implemented. Particle flux and parallel current are computed, with evidence of particle (Ware) pinch and "bootstrap" current, on top of corrections on the Spitzer resistivity. The collisional electron heat diffusivity is also predicted. Finally, 3D (non-axisymmetric) effects are included and illustrated with the effect of magnetic field ripple in tokamaks. Sections labelled with a star "*" can be skipped on first reading. The symbol is used here with the meaning of an estimate, i.e. numerical factors are kept-conversely the symbol ∼ labels a scaling-hence numerical factors are removed.
Domains
Physics [physics]
Origin : Files produced by the author(s)
licence : CC BY NC ND - Attribution - NonCommercial - NoDerivatives
licence : CC BY NC ND - Attribution - NonCommercial - NoDerivatives