title: Zonal flow dynamics and control of turbulent transport in stellarators.
abstract: The relation between magnetic geometry and the level of ion-temperature-gradient (ITG) driven turbulence in stellarators is explored through gyrokinetic theory and direct linear and nonlinear simulations. It is found that the ITG radial heat flux is sensitive to details of the magnetic configuration that can be understood in terms of the linear behavior of zonal flows. The results throw light on the question of how the optimization of neoclassical confinement is related to the reduction of turbulence.
authors.affiliation: Max-Planck-Institut für Plasmaphysik, Teilinstitut Greifswald, Wendelsteinstrasse 1, D-17491 Greifswald, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Xanthopoulos
authors.forename: A
authors.initials: A
authors.lastname: Mischchenko
authors.forename: P
authors.initials: P
authors.lastname: Helander
authors.forename: H
authors.initials: H
authors.lastname: Sugama
authors.forename: T-H
authors.initials: TH
authors.lastname: Watanabe