Interaction between neoclassical effects and ion temperature gradient turbulence in gradient- and flux-driven gyrokinetic simulations
Artikel i vetenskaplig tidskrift, 2016

Neoclassical and turbulent transport in tokamaks has been studied extensively over the past decades, but their possible interaction remains largely an open question. The two are only truly independent if the length scales governing each of them are sufficiently separate, i.e., if the ratio ρ∗ between ion gyroradius and the pressure gradient scale length is small. This is not the case in particularly interesting regions such as transport barriers. Global simulations of a collisional ion-temperature-gradient-driven microturbulence performed with the nonlinear global gyrokinetic code Gene are presented. In particular, comparisons are made between systems with and without neoclassical effects. In fixed-gradient simulations, the modified radial electric field is shown to alter the zonal flow pattern such that a significant increase in turbulent transport is observed for ρ1/300. Furthermore, the dependency of the flux on the collisionality changes. In simulations with fixed power input, we find that the presence of neoclassical effects decreases the frequency and amplitude of intermittent turbulent transport bursts (avalanches) and thus plays an important role for the self-organisation behaviour.

Författare

Michael Oberparleiter

Chalmers, Rymd- och geovetenskap, Plasmafysik och fusionsenergi

F. Jenko

University of California

Daniel Told

University of California

Hauke Doerk

Max Planck-institutet

Frank Jenko

Max Planck-institutet

Physics of Plasmas

1070-664X (ISSN) 1089-7674 (eISSN)

Vol. 23 4 042509

Styrkeområden

Energi

Fundament

Grundläggande vetenskaper

Ämneskategorier

Annan fysik

Fusion, plasma och rymdfysik

DOI

10.1063/1.4947200

Mer information

Senast uppdaterat

2018-02-28