Shearing effects on density burst propagation in SOL plasmas

SOL turbulence is characterised by intermittent ballistic transport of density fronts. The interaction of such density structures with velocity shear layers is found to yield shearing effects over scales that are comparable to those of the fronts. Enhanced diffusion transport governed by the thinning of the radial extent of the density structure governs the decay of such a structure over a Dupree time. Velocity shear layers extending poloidally over a fraction of the poloidal wave length can also exhibit a stopping capability due to the collapse of the radial velocity within the shear layer. The penetration of the density structure within such a barrier is of the order of five hybrid Larmor radius.