Effects of toroidal rotation on electron heat transport via changes in inertial force and impurity density
Effects of toroidal rotation on electron heat transport via changes in inertial force and impurity density
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DOI：
10.1088/1361-6587/aa5e02
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发表时间：
2017-03
影响因子：
2.2
通讯作者：
E. Narita;M. Honda;M. Yoshida;N. Hayashi;H. Urano;S. Ide
中科院分区：
文献类型：
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作者：
E. Narita;M. Honda;M. Yoshida;N. Hayashi;H. Urano;S. Ide
两种类型的JT-60 U放电进行了研究，重点是环形旋转：在一种放电中，其特征在于存在内部传输势垒（ITB），核心区域中的电子热传输受到环形旋转方向的影响，而在另一种放电中，其是没有ITB的常规H模式等离子体，没有观察到环向旋转方向和电子热传输之间的明显相关性。在这两种放电中，杂质密度也被发现与旋转速度分布一起变化。用磁通管回旋动力学程序，我们发现在这些放电中，旋转速度分布和杂质密度的变化对电子热输运的影响是不同的。包括这些影响解释了实验中观察到的趋势。首先，关于通过惯性力影响热传输的旋转速度分布，热传输对旋转方向的依赖性根据旋转速度的梯度而改变。接着，杂质密度的增加使离子温度梯度模式稳定，但可使俘获电子模式不稳定。因此，它被发现，在这些放电中的杂质密度对电子热输运的影响的差异可以归因于在主导的不稳定性的差异。
Two types of JT-60U discharges are studied with an emphasis on toroidal rotation: in one discharge, which is characterized by the existence of an internal transport barrier (ITB), electron heat transport in the core region is affected by the toroidal rotation direction, while in the other discharge, which is a conventional H-mode plasma without an ITB, the clear correlation between the toroidal rotation direction and electron heat transport is not observed. In both discharges, the impurity density is also found to vary together with the rotation velocity profile. With a flux-tube gyrokinetic code, we have found that the effects of the changes in the rotation velocity profile and the impurity density on electron heat transport are different between these discharges. Including the effects explains the tendency observed in the experiments. First, regarding the rotation velocity profile, which influences heat transport through the inertial force, the dependence of heat transport on the rotation direction changes, according to the gradient of the rotation velocity. Next, an increase in the impurity density stabilizes the ion temperature gradient mode, but can destabilize the trapped electron mode. Therefore, it is found that the difference in the impact of the impurity density on electron heat transport in these discharges can be attributed to the difference in the dominant instability.