The physics of E × B shear, zonal flows and streamers in tokamak edge turbulence
The role of E × B flow shear in reducing turbulent transport in the edge region of a tokamak is investigated using 3D non-linear global simulations. Transport reduction is found to be due to both a decrease of fluctuation amplitudes as well as a change in their relative phase. A scaling of the turbulent diffusivity with E × B flow shear has been deduced from these simulations. This scaling agrees with recent experimental observations as well as analytical models. Moreover these simulations allow us to examine the dynamics of anisotropic secondary flows such as zonal flows and streamers. These flows are found to regulate intermittent transport observed in flux driven simulations.
Bibliographic Reference: An article published in: Contributions to Plasma Physics, Volume 42, Issue 2-4, (2002), pp.362-371
Availability: This article can be accessed online by subscribers, and can be ordered online by non-subscribers, at: http://dx.doi.org/10.1002/1521-3986%28200204%2942:2/4
Record Number: 200316020 / Last updated on: 2003-03-06
Original language: en
Available languages: en