Three-dimensional fluid simulations of a simple magnetized toroidal plasma

Three-dimensional fluid simulations are performed in a simple magnetized toroidal plasma, in which vertical and toroidal magnetic fields create helicoidal magnetic field lines that terminate on the torus vessel. The simulations are carried out in the three-dimensional flux tube that wraps around the torus and are able to describe both interchange and drift-wave dynamics. The presence of different turbulence regimes is pointed out; in particular, it is shown that turbulence can be quenched by either a sufficiently large plasma source, or a sufficiently small vertical field, or a sufficiently high parallel resistivity. The simulations considered herein reveal that interchange turbulence dominates over the drift-wave dynamics. Considering the experimental observations, we finally discuss the limitations of the present model.