  The stochastic advection of low energy deuterium ions is studied in a three
dimensional realistic turbulence model in conditions relevant for current
tokamak fusion experiments. The diffusion coefficients are calculated starting
from the test particles trajectories in the framework of the semi-analitical
statistical model called the Decorrelation Trajectory Method. We show that
trajectory trapping determined by the space correlation of the velocity field
is the main cause for anomalous diffusion and we obtain the transport regimes
corresponding to different values of the parameters of the turbulence model and
a trapping condition in the limit of frozen turbulence. Depending on the value
of the parameters of the model, the interaction between turbulence and magnetic
drifts leads to both an increase (with transport in the poloidal direction
increasing up to an order of magnitude) and a decrease of the particle
transport.
