TY - JOUR
AU - Parker, Scott
AB - Abstract: The derivation of an intermediate-scale gyrokinetic-electron theory in nonuniform tokamak plasmas [Chen H. 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 zonal flow 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 zonal flow 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 zonal flows regulate intermediate-scale electron heat flux transport to levels in the predicted range.
TI - Zonal Flow Excitation in Electron-Scale Turbulence
JF - Physics
DO - 10.48550/arXiv.2211.02140
DA - 2022-11-03
UR - https://www.deepdyve.com/lp/arxiv-cornell-university/zonal-flow-excitation-in-electron-scale-turbulence-rzjBUpjQUE
VL - 2022
IS - 2211
DP - DeepDyve
ER -