The role of plasma elongation on the linear damping of zonal flows

Autor: Ph. Ghendrih, T. M. Tran, Ben F. McMillan, Guilhem Dif-Pradalier, Virginie Grandgirard, Alberto Bottino, Yanick Sarazin, Laurent Villard, S. Jolliet, Paolo Angelino, Xavier Garbet
Jazyk: angličtina
Rok vydání: 2008
Předmět:
Zdroj: Physics of Plasmas
Physics of Plasmas, v.15 (2008)
Popis: Drift wave turbulence is known to self-organize to form axisymmetric macroscopic flows. The basic mechanism for macroscopic flow generation is called inverse energy cascade. Essentially, it is an energy transfer from the short wavelengths to the long wavelengths in the turbulent spectrum due to nonlinear interactions. A class of macroscopic flows, the poloidally symmetric zonal flows, is widely recognized as a key constituent in nearly all cases and regimes of microturbulence, also because of the realization that zonal flows are a critical agent of self-regulation for turbulent transport. In tokamaks and other toroidal magnetic confinement systems, axisymmetric flows exist in two branches, a zero frequency branch and a finite frequency branch, named Geodesic Acoustic Modes (GAMs). The finite frequency is due to the geodesic curvature of the magnetic field. There is a growing body of evidence that suggests strong GAM activity in most devices. Theoretical investigation of the GAMs is still an open field of ...
Databáze: OpenAIRE