Turbulent momentum pinch of diamagnetic flows in a tokamak

Abstract

The diamagnetic flow due to the radial pressure and temperature gradients and the E × B flow due to the radial electric field induce different turbulent momentum fluxes in a tokamak. As a result, when the diamagnetic and E × B flows cancel giving zero net toroidal rotation, there will still be finite momentum transport. This may be particularly important near the plasma–wall boundary where a strong pressure drop is established and the two types of flows are similar in size and opposite in direction. The different momentum fluxes in this region can give significant intrinsic rotation peaking in the core with scaling and values similar to those observed in high confinement mode plasmas.