ON NON-MARKOVIAN RELATIVE DIFFUSION OF STOCHASTIC MAGNETIC LINES

In this paper we study some aspects related to the spatial relative di ffusion of the magnetic-field lines. The nonlinear integral equation f or the Lagrangian correlation is transformed into a system of two ordi nary differential equations and solved numerically. The system of line ar integro-differential equations for the moments is analysed numerica lly for different values of the alpha-parameter (which is proportional to the ratio of parallel and perpendicular correlation lengths). A cr itical value for alpha (alpha(crit) = 0.3251) is obtained in a shearle ss stochastic magnetic-field model. For alpha > alpha(crit) the rate o f damping of the anisotropy becomes complex, that means an oscillatory behaviour for the correlations and anisotropies. For alpha < alpha(cr it) we find the well known behaviour described in the literature for a lpha much less than 1.