par Petrisor, Iulian;Negrea, Marian;Weyssow, Boris 
Référence Physica Scripta, 75, page (1-12)
Publication Publié, 2007
Référence Physica Scripta, 75, page (1-12)
Publication Publié, 2007
Article révisé par les pairs
| Résumé : | The electron diffusion induced by a two-dimensional electrostatic turbulence, in a sheared slab approximation of the toroidal magnetic geometry, is studied firstly using the decorrelation trajectory method (DCT), secondly by direct numerical simulation. The former semi-analytical method allows us to go beyond the Corrsin approximation, thus allowing for a non-classical analysis of the particle trapping phenomenon. The DCT results are compared to the transport properties of the electrons obtained by numerical simulations assuming an isotropic spectrum of electrostatic drift type turbulence that is Gaussian for small wavevectors and power-law k-3 for large wavevectors. The 'radial' and the 'poloidal' running and asymptotic diffusion coefficients of thermal electrons are obtained for physically relevant parameter values. The existence of enhanced diffusion in the poloidal direction is observed in the presence of magnetic shear. The agreement between the semi-analytical method and the purely numerical method is pointed out. © 2006 The Royal Swedish Academy of Sciences. |
