Vortex-induced diffusivity in reversed field pinch plasmas

• Coherent structures identified in two reversed field pinch experiments are interpreted as a dynamic balance of dipolar and monopolar vortices growing and evolving under the effect of the ExB flow shear. For the first time their contribution to the anomalous transport has been estimated in fusion related plasmas, showing that they can account for up to 50% of the total plasma diffusivity. The experimental findings indicate that the diffusion coefficient associated with the coherent structures depends on the relative population of the two types of vortices and is minimum when the two populations are equal. An interpretative model is proposed to explain this feature.

Ämnesord

NATURVETENSKAP  -- Fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences (hsv//eng)

Nyckelord

electrostatic turbulence

coherent structures

edge turbulence

velocity shear

transport

tokamak

intermittency

dynamics

vortices

flows

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)