Spatio-temporal structure of the edge radial electric field during H-mode in JT-60U
Spatio-temporal structure of the edge radial electric field during H-mode in JT-60U
复制标题
JT-60U H模式边缘径向电场时空结构
DOI：
10.1088/0029-5515/51/5/053009
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发表时间：
2011
期刊：
影响因子：
3.3
通讯作者：
T. Kurki
中科院分区：
文献类型：
--
作者：
K. Kamiya;Y. Sakamoto;G. Matsunaga;A. Kojima;H. Urano;N. Oyama;Y. Koide;Y. Kamada;K. Ida;T. Kurki
高空间和高时间分辨率的电荷交换复合光谱测量使JT-60U托卡马克外围区域的径向电场(Er)的评估成为可能，具有更好的信噪比。在密度很低(~lt；1×1019 m−3)的L模相中，在离子温度(Ti)升高之前，Er的梯度(或相当于极向旋转的Vθ)开始增加。当r/a>；0.94区的Er值开始变为负值，下降到−40 Kv m−1(类似于Vϕ)时，同一区域的钛剖面的陡化加速。尽管Vϕ的数值比Vθ的数值小得多，但它对剪切的贡献可能是显著的：而对于r/a⩾0.90Vϕ变得越来越负；对于r/a和lt；0.90时它同时变得越来越正。在无ELM H模相的后期，观察到边缘ER值在弱负和强负之间的清晰分叉，基本相同的约束性质对应于两个截然不同的E×B剪切率。“正常的”Elmy H模只有在分叉之后才会发生。结果表明，能量约束的改善并不一定与湍流的E×B剪切抑制有关。
Charge exchange recombination spectroscopy measurements with high spatial and temporal resolution have made the evaluation of the radial electric field (Er) in the JT-60U tokamak peripheral region possible with a better signal-to-noise ratio. In a very low density (<1 × 1019 m−3) L-mode phase, the gradient in Er (or, equivalently, in poloidal rotation, Vθ) was found to start increasing prior to an increase in the ion temperature (Ti). As the Er values in the region r/a > 0.94 started to become negative, down to −40 kV m−1 (similar to Vϕ), the steepening of the Ti profile in the same region accelerated. Even though the numerical value of Vϕ was considerably smaller than that of Vθ, its contribution to shear could be significant: while for r/a ⩾ 0.90 Vϕ became increasingly negative; it simultaneously became increasingly positive for r/a < 0.90. Clean bifurcations in the edge Er values between weak negative and strong negative ones were observed in the later ELM-free H-mode phase, with essentially the same confinement properties corresponding to two very different E × B shearing rates. The ‘normal’ ELMy H-mode took place only after the bifurcations. The results indicate that energy confinement improvement may not necessarily be connected to E × B shear suppression of turbulence.
减少 JFT-2M HRS H 模式等离子体中的偏滤器热负荷、等离子体形状效应和径向电场结构
DOI：
--
发表时间：
2006
期刊：
Nuclear Fusion 46
影响因子：
--
作者：
神谷健作;大山直幸;三浦幸俊;他
通讯作者：
他