Zonal flow excitation in electron-scale tokamak turbulence
Zonal flow excitation in electron-scale tokamak turbulence
复制标题
电子级托卡马克湍流中的层流激发
DOI：
10.1088/1741-4326/acab15
复制
发表时间：
2022
期刊：
影响因子：
3.3
通讯作者：
S. Parker
中科院分区：
文献类型：
--
作者：
Stefan Tirkas;Haotian Chen;G. Merlo;F. Jenko;S. Parker
非均匀托卡马克等离子体中尺度回旋动力学电子理论的推导（Chen et al . 2021）。核聚变61 066017)表明，Navier-Stokes型非线性耦合电子-温度梯度（ETG）模式和纬向流（ZF）模式，其波长远短于离子的陀螺半径，但远长于电子的陀螺半径。这种中等尺度的ETG-ZF耦合通常比流体近似的Hasegawa-Mima型非线性特性更强，预计将导致相关的ZF产生和ETG模式调节。本文给出了包括单模ETG和全谱ETG湍流在内的电子尺度、连续体、陀螺动力学模拟结果。研究了单模ETG产生的ZF，发现单模的中尺度结果与理论一致。然后给出全谱结果，并用单模结果定性地解释。发现etg驱动的ZFs将中尺度电子热通量输运调节到预测范围内的水平。
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.