Anomalous, quasilinear, and percolative regimes for magnetic-field-line transport in axially symmetric turbulence

We studied a magnetic turbulence axisymmetric around the unperturbed magnet ic field for cases having different ratios l(parallel to)/l(perpendicular t o). We find, in addition to the fact that a higher fluctuation level delta B/B-0 makes the system more stochastic, that by increasing the ratio l(para llel to)/l(perpendicular to), at fixed delta B/B-0, the stochasticity incre ases. It appears that the different transport regimes can be organized in t erms of the Kubo number R = (delta B/B-0)(l(parallel to)/l(perpendicular to )). The simulation results are compared with the two analytical limits, tha t is the percolative limit and the quasilinear limit. When R much less than 1 weak chaos, closed magnetic surfaces, and anomalous transport regimes ar e found. When R approximate to 1 the diffusion regime is Gaussian, and the quasilinear scaling of the diffusion coefficient D(perpendicular to)similar to(delta B/B-0)(2) is recovered. Finally, for R much greater than 1 the pe rcolation sealing of the diffusion coefficient D(perpendicular to)similar t o(delta B/B-0)(0.7) is obtained.