Effects of equilibrium radial electric field on ion temperature gradient instability in the scrape-off layer of a field-reversed configuration
Effects of equilibrium radial electric field on ion temperature gradient instability in the scrape-off layer of a field-reversed configuration
复制标题
平衡径向电场对场反转结构刮除层离子温度梯度不稳定性的影响
DOI：
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发表时间：
2021
影响因子：
2.2
通讯作者：
T. Tajima
中科院分区：
文献类型：
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作者：
W. Wang;J. Bao;X. Wei;Z. Lin;G. Choi;S. Dettrick;A. Kuley;C. Lau;P. Liu;T. Tajima
利用回旋粒子模拟方法研究了平衡径向电场对场反转结构的刮除层（SOL）中离子温度梯度（ITG）不稳定性的线性和非线性影响.绝热电子的线性模拟发现，E×B流剪切降低了生长速率，并导致环面上模结构的径向倾斜。非线性模拟发现，E×B流剪切通过减小湍流强度和涡尺寸，显著降低了ITG饱和振幅和SOL中的离子热输运。湍流强度是由流体涡动旋转决定的，这是单一环形模数的SOL ITG不稳定性的主要饱和机制。另一方面，平行波粒解相关是SOL ITG湍流输运的主导机制。以引导中心径向偏移量为特征长度尺度，以涡流翻转时间为特征时间尺度的随机游走模型，很好地拟合了E×B流切变对离子热导率的标度。
Linear and nonlinear effects of the equilibrium radial electric field on the ion temperature gradient (ITG) instability in the scrape-off layer (SOL) of a field-reversed configuration have been studied using gyrokinetic particle simulations for a single toroidal mode. Linear simulations with adiabatic electrons find that the E×B flow shear reduces the growth rate and causes a radial tilting of the mode structure on the toroidal plane. Nonlinear simulations find that the E×B flow shear significantly decreases ITG saturation amplitude and ion heat transport in the SOL by reducing both turbulence intensity and eddy size. The turbulence intensity is determined by fluid eddy rotation, which is the dominant saturation mechanism for the SOL ITG instability with a single toroidal mode number. On the other hand, parallel wave-particle decorrelation is the dominant mechanism for the SOL ITG turbulent transport. A random walk model using the guiding center radial excursion as the characteristic length scale and the eddy turnover time as the characteristic time scale fits very well to the scaling of ion heat conductivity with the E×B flow shear.
影响因子：
2.2
作者：
P. Abdoul;D. Dickinson;C. Roach;H. Wilson
通讯作者：
P. Abdoul;D. Dickinson;C. Roach;H. Wilson