Effects of the parallel acceleration on heavy impurity transport in turbulent tokamak plasmas

Abstract A process specific to the dynamics of heavy impurities in turbulent tokamak plasmas is found and analyzed. We show that parallel stochastic acceleration strongly coupled perpendicular transport generates a radial pinch velocity. The interaction produced with hidden drifts, quasi-coherent component motion consists pair average velocities opposite directions. breaks this symmetry yields velocity can be inward or outward direction. generated three-dimensional turbulence, presence poloidal It significant only for heavy, high Z ions. tungsten ions analyzed frame minimal test particle model mechanism. use semi-analytical method numerical simulations. scaling laws diffusion coefficient are order drive clear physical image these non-linear effects. conclude by accelerated rather strong impurities.