Global Gyrokinetic Simulation of Tokamak Edge Pedestal Instabilities
Weigang Wan, Scott E. Parker, Yang Chen, Zheng Yan, Richard J., Groebner, and Philip B. Snyder
TL;DR
This paper uses global electromagnetic gyrokinetic simulations to analyze edge pedestal instabilities in tokamaks, revealing how magnetic shear and collisions influence the stability of kinetic ballooning and peeling-ballooning modes.
Contribution
It demonstrates the existence of near-threshold conditions for KBM and KPBM modes in the edge pedestal and shows how magnetic shear reduction stabilizes KPBM while slightly destabilizing KBM.
Findings
Magnetic shear reduction stabilizes KPBM.
Collisions lower the KBM critical beta and increase growth rate.
Near-threshold conditions exist for both modes in DIII-D H-mode discharges.
Abstract
Global electromagnetic gyrokinetic simulations show the existence of near threshold conditions for both a high- kinetic ballooning mode (KBM) and an intermediate- kinetic version of peeling-ballooning mode (KPBM) in the edge pedestal of two DIII-D H-mode discharges. When the magnetic shear is reduced in a narrow region of steep pressure gradient, the KPBM is significantly stabilized, while the KBM is weakly destabilized and hence becomes the most-unstable mode. Collisions decrease the KBM's critical and increase the growth rate.
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.