Year: 2024
Type: article
Abstract: Recent experimental findings on limit-cycle-oscillations indicate that the nonlinear driving of the turbulent poloidal Reynolds stress to zonal flows (ZFs) is not a significant factor in the toroidal geometry, sparking fundamental controversial issues within the fusion community. By using the global nonlinear gyrokinetic simulations, we propose a unified mesoscale picture of nonlinear driving of ZFs in the ion-temperature-gradient turbulence. ZFs are nonlinearly driven by the turbulent energy flux and the turbulent poloidal Reynolds stress. The turbulent energy flux is not shielded by the toroidal geometry effect in nonlinearly driving ZFs. The turbulent poloidal Reynolds stress is not shielded on the time scale shorter than the ion bounce period; however, on the time scale longer than the ion bounce period, the turbulent poloidal Reynolds stress is indeed shielded by the toroidal geometry effect.
Source: Nuclear Fusion
Authors: Zihao Wang, Shaojie Wang
Institution: University of Science and Technology of China
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,470
Award: G1689871981
OpenAlex ID: W4404592543