Temporal and spatial responses of temperature, density and rotation to electron cyclotron heating in JT-60U
Temporal and spatial responses of temperature, density and rotation to electron cyclotron heating in JT-60U
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JT-60U 中温度、密度和旋转对电子回旋加速器加热的时空响应
DOI：
10.1088/0029-5515/53/8/083022
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发表时间：
2013
期刊：
影响因子：
3.3
通讯作者：
M. Yoshida
中科院分区：
文献类型：
--
作者：
成田絵美;本多充;林伸彦;et al.;M. Yoshida
在JT-60 U上研究了具有相对尖峰Ti分布的正剪切H模等离子体和内输运势垒（ITB）等离子体中电子通道（电子密度ne和电子温度Te）和离子通道（离子温度Ti和环向旋转速度V φ）对中心电子回旋加热（ECH）的时空响应.离子温度随着电子电荷的增加而降低，而电子电荷的增加是在核心区电子温度增加之后。在H模等离子体中，Ti变化的时间尺度为30-60 ms，半径几乎不变。在ITB等离子体中，ITB脚周围的时间尺度较短，ITB脚内部的时间尺度变长。实验测量的因果关系表明，在T i的减少是一致的离子温度梯度临界梯度降低。通过与线性陀螺稳定性分析的比较，也验证了这一点。在H模式和ITB等离子体中，电子热扩散率随着ECH而增加，与离子热扩散率的增加相关。具有相对平坦的n e轮廓的电子密度不随ECH而降低。另一方面，具有峰值的n e轮廓的电子密度随着ECH而减小。的n-e分布的平坦化后，观察到的核心区域中的电子温度的增加。的时间尺度的变化，在NE是约200-350毫秒。线性gyrokinetic稳定性分析意味着被困的电子模式，这增加了向外的粒子通量的增长率，在ECH变得更加明显。在H模等离子体中，利用小转矩输入（BAL-NBI），识别了ECH的逆内禀旋转。逆内禀旋转是在电子温度增加后产生的，并且与EC沉积周围的ECH的电子温度的变化相关。观察到反内旋的径向区域比电子温度随ECH变化的径向区域宽。环向旋转速度变化的时间尺度在ECH沉积附近约为90-200 ms，并且比Te和Ti变化的时间尺度长。
The temporal and spatial responses of electron channels (the electron density, n e, and the electron temperature, T e) and ion channels (the ion temperature, T i, and the toroidal rotation velocity, V φ) to central electron cyclotron heating (ECH) have been investigated in positive shear H-mode plasmas with a relatively peaked T i profile and internal transport barrier (ITB) plasmas on JT-60U. Ion temperature decreases with ECH after the increase in the electron temperature in the core region. The time scale of the change in T i is≈ 30–60 ms in H-mode plasmas and almost constant in radius. In ITB plasmas, the time scale is shorter around the ITB foot and becomes longer inside the ITB foot. The experimentally measured causality indicates that the decrease in T i is consistent with the ion temperature gradient critical gradient reduction. This is also verified through a comparison with linear gyrokinetic stability analyses. The electron heat diffusivity increases with ECH in both H-mode and ITB plasmas, correlating to the increase in the ion heat diffusivity. Electron density with a relatively flat n e profile does not decrease with ECH. On the other hand, the electron density with a peaked n e profile decreases with ECH. The flattening of the n e profile is observed after the increase in the electron temperature in the core region. The time scale of the change in n e is about 200–350 ms. Linear gyrokinetic stability analyses imply that the growth rate of the trapped electron modes, which increase outward particle flux, becomes more pronounced during ECH. The counter intrinsic rotation with ECH is identified on H-mode plasmas with a small torque input (BAL-NBI). The counter intrinsic rotation is generated after the increase in the electron temperature and correlates to the change in the electron temperature with ECH around the EC deposition. The radial region where the counter intrinsic rotation is observed is wider than the radial region where the electron temperature varies with ECH. The time scale of the change in the toroidal rotation velocity is about 90–200 ms around the ECH deposition and longer than the time scale of the change in T e and T i.