Toroidal plasma rotation in the TCV tokamak
Toroidal plasma rotation in the TCV tokamak
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DOI：
10.1088/0741-3335/48/5/012
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发表时间：
2006-05
影响因子：
2.2
通讯作者：
A. Scarabosio;A. Bortolon;B. Duval;A. Karpushov;A. Pochelon
中科院分区：
文献类型：
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作者：
A. Scarabosio;A. Bortolon;B. Duval;A. Karpushov;A. Pochelon
首次测量了无外动量注入的TCV欧姆L模等离子体中的环向旋转。完全剥离的碳物质的环向速度分布通过活性电荷交换蒸发光谱法测量，其时间分辨率通常为90 ms，空间分辨率为2.5 cm，约为等离子体半径的1/10。所观察到的碳的速度是氘的抗磁漂移速度的顺序和氘的热速度的1/5。它的方向与等离子体电流的电子反磁环向漂移方向相反。当反转等离子体电流时，曲线反转。角速度分布是平坦的，或中空的，在反转半径内，并向等离子体边缘准线性地减小。通过在TCV容器内垂直移动等离子体磁轴，获得了高分辨率的等离子体边缘速度分布。这样的实验证实，接近限制器，静止旋转速度接近零或稍微正（并流定向）。这表明角动量不是从等离子体边缘驱动的。最大碳速度的比例为v，Max [km s−1] = −12.5Ti/Ip [eV/kA]，适用于密度和边缘安全系数值的显著范围。与新经典理论的比较表明，TCV等离子体的旋转主要是由径向电场驱动的，而环向电场的贡献可以忽略不计。新经典小环转动理论在定量和定性上都与实验观测不一致。另一个经验方程的角动量通量，能够重现反演半径以外的测量固定的配置文件，提出。
The first toroidal rotation measurements in TCV ohmic L-mode plasmas with no external momentum injection are presented. The toroidal velocity profile of the fully stripped carbon species is measured by active Charge eXchange Recombination Spectroscopy with a temporal resolution of typically 90 ms and a spatial resolution of 2.5 cm, about 1/10 of the plasma radius. The observed carbon velocity is of the order of the deuterium diamagnetic drift velocity and up to 1/5 of the deuterium thermal velocity. It is directed opposite to plasma current in the electron diamagnetic toroidal drift direction. The profile reverses when reversing the plasma current. The angular velocity profile is flat, or hollow, inside the sawtooth inversion radius and decreases quasi linearly towards the plasma edge. By vertically shifting the plasma magnetic axis within the TCV vessel the plasma edge velocity profile was measured with high resolution. Such experiments confirm that, close to the limiter, the stationary rotation velocity is close to zero or somewhat positive (co-current directed). This suggests that the angular momentum is not driven from the plasma edge. The maximum carbon velocity scales as vϕ,Max [km s−1] = −12.5Ti/Ip [eV/kA] for a significant range of densities and values of the edge safety factor. Comparison with neoclassical predictions show that the TCV plasma rotation is mainly driven by radial electric fields, with a negligible contribution from the toroidal electric fields. The neoclassical theory of small toroidal rotation quantitatively and qualitatively disagrees with the experimental observation. An alternative empirical equation for the angular momentum flux, able to reproduce the measured stationary profile outside the inversion radius, is proposed.