Article

Abstract

• The derivation of an intermediate-scale gyrokinetic-electron theory in nonuniform tokamak plasmas (Chen et al 2021 Nucl. Fusion 61 066017) has shown that a Navier–Stokes type nonlinearity couples electron-temperature-gradient (ETG) modes and zonal flow (ZF) modes with wavelengths much shorter than the ion gyroradius but much longer than the electron gyroradius. This intermediate-scale ETG-ZF coupling is typically stronger than the Hasegawa–Mima type nonlinearity characteristic of the fluid approximation and is predicted to lead to relevant ZF generation and ETG mode regulation. Electron-scale, continuum, gyrokinetic simulation results are presented here which include both single-mode ETG and full-spectrum ETG turbulence. The ZF generation due to single ETG modes is investigated and the single-mode intermediate-scale results are found to be in agreement with theory. The full-spectrum results are then presented and explained qualitatively in terms of the single-mode results. It is found that the ETG-driven ZFs regulate intermediate-scale electron heat flux transport to levels in the predicted range.

   

Creator

• Tirkas, Stefan
• Jenko, Frank
• Parker, Scott E
• Chen, Haotian
• Merlo, Gabiele

Date Issued

• 2023

Academic Affiliation

• Physics

Journal Title

• Nuclear Fusion

Journal Issue/Number

• 2

Journal Volume

• 63

Last Modified

• 2024-11-07

Resource Type

• Article

Rights Statement

• In Copyright

DOI

•  https://doi.org/10.1088/1741-4326/acab15

ISSN

• 1741-4326

Language

• English [eng]

License

• Creative Commons BY Attribution 4.0 International

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