Regulation of electron temperature gradient turbulence by zonal flows driven by trapped electron modes
Regulation of electron temperature gradient turbulence by zonal flows driven by trapped electron modes
复制标题
DOI：
10.1063/1.4875740
复制
发表时间：
2014-05-01
影响因子：
2.2
通讯作者：
Tsuji-Iio, S.
中科院分区：
文献类型：
--
作者：
Asahi, Y.;Ishizawa, A.;Tsuji-Iio, S.
用回转动力学模拟方法研究了电子温度梯度(ETG)模引起的湍流输运。研究发现，ETG湍流可以由捕获电子模驱动的中尺度纬向流来调节，而捕获电子模的增长速率比ETG模的增长速率小得多。径向波长位于离子和电子香蕉宽度之间的纬向流不被捕获的离子或电子屏蔽，因此它们有效地被TEM驱动。结果还表明，瞬变电磁驱动纬向流的E×B切变率大于或相当于长波ETG模和TEM的增长率，它们对纬向流激发前的湍流输送有主要贡献。(C)2014 AIP出版有限责任公司。
Turbulent transport caused by electron temperature gradient (ETG) modes was investigated by means of gyrokinetic simulations. It was found that the ETG turbulence can be regulated by meso-scale zonal flows driven by trapped electron modes (TEMs), which are excited with much smaller growth rates than those of ETG modes. The zonal flows of which radial wavelengths are in between the ion and the electron banana widths are not shielded by trapped ions nor electrons, and hence they are effectively driven by the TEMs. It was also shown that an E x B shearing rate of the TEM-driven zonal flows is larger than or comparable to the growth rates of long-wavelength ETG modes and TEMs, which make a main contribution to the turbulent transport before excitation of the zonal flows. (C) 2014 AIP Publishing LLC.