Accumulation of spectral energy in 2D fluid turbulence and generation of zonal flows in magnetized plasma

Michael Shats
Senior Fellow, Plasma Research Laboratory
Research School of Physical Sciences and Engineering
The Australian National University

Abstract

Michael Shats, Hua Xia and Horst Punzmann

A similarity between spectral condensation in 2D fluid turbulence and
generation of zonal flows in toroidally confined plasma is supported by
recent experimental results. Systematic studies of spectral condensation of
turbulence are performed in the electromagnetically driven quasi-2D
turbulence in thin layers of electrolyte. When turbulence is placed in the
square boundary the inverse energy cascade leads in some cases to the
accumulation of the turbulent energy at the scale determined by the box
size. This is manifested as the self-organization of turbulence into a
coherent flow. The evolution of the turbulence spectra is very similar to
the modification of  spectra in the Hasegawa-Mima-type turbulence in
toroidal plasma measured in the toroidal heliac during the L-H confinement
transitions. The universality of self-organization in these two systems is discussed.