The role of magnetic shear for zonal flow generation
J. Anderson, H. Nordman
TL;DR
This paper analytically investigates how magnetic shear influences the generation of zonal flows by ITG and TE mode turbulence in tokamaks, revealing that negative magnetic shear enhances ZF growth, especially for TE modes.
Contribution
It provides a new analytical understanding of the magnetic shear's impact on zonal flow generation, highlighting the significance of electron magnetic drifts in TE mode turbulence.
Findings
Large ZF levels occur in regions of negative magnetic shear.
TE mode driven ZF growth scales strongly with magnetic shear.
Bounce averaging of electron magnetic drifts explains the scaling behavior.
Abstract
The role of magnetic shear for zonal flow generation by ion-temperature-gradient (ITG-) and trapped electron (TE-) mode turbulence is studied analytically using fluid descriptions. The scaling of the zonal flow (ZF) growth rate with magnetic shear is examined and compared with linear growth rates for typical tokamak parameter values. The results indicate that large levels of ZF are obtained in regions of negative magnetic shear, in particular for ZF driven by TE mode turbulence. The strong magnetic shear scaling obtained for TE mode driven zonal flows originates from the bounce average of the electron magnetic drifts.
Peer Reviews
No public reviews on file for this paper yet. If you reviewed it on a platform where reviews are public (OpenReview, ICLR, NeurIPS, ICML), you can paste yours below so the community can read it here.
Videos
No videos yet. Explain this paper in a talk, walkthrough, or lecture? Add one.