Experimental characterization of multiscale and multifield turbulence as a critical gradient threshold is surpassed in the DIII-D tokamaka)
Experimental characterization of multiscale and multifield turbulence as a critical gradient threshold is surpassed in the DIII-D tokamaka)
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DOI：
10.1063/1.4807123
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发表时间：
2013-05
影响因子：
2.2
通讯作者：
J. Hillesheim;J. Deboo;W. Peebles;T. Carter;Gang Wang;T. Rhodes;L. Schmitz;G. McKee;Zheng Yan;G. Staebler;K. Burrell;E. Doyle;C. Holland;C. Petty;Sterling P. Smith;A. White;L. Zeng
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文献类型：
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作者：
J. Hillesheim;J. Deboo;W. Peebles;T. Carter;Gang Wang;T. Rhodes;L. Schmitz;G. McKee;Zheng Yan;G. Staebler;K. Burrell;E. Doyle;C. Holland;C. Petty;Sterling P. Smith;A. White;L. Zeng
在DIII-D托卡马克实验中观察到长波长（kθρs <$0.4）电子温度涨落的临界梯度[J. L. Luxon，Nucl. Fusion 42，614（2002）]，其中低于阈值LTe-1=|特|/Te电子温度波动是恒定的，并且在它们之上稳步增加。在临界梯度以上，由功率平衡推断的电子热通量也迅速增加。临界梯度是由线性不稳定性引起的湍流的预测属性，并且被认为与传输刚度有关。本文的结果首次直接、系统地证明了托卡马克湍流测量中的临界梯度行为。实验是通过改变电子回旋加热的沉积位置来进行的，以在L模式等离子体中局部扫描r/a = 0.6的LTe−1;旋转也通过改变中性束注入的动量输入来改变。用相关电子循环测量了温度波动。
A critical gradient for long wavelength (kθρs≲0.4) electron temperature fluctuations has been observed in an experiment in the DIII-D tokamak [J. L. Luxon, Nucl. Fusion 42, 614 (2002)], where below a threshold value of LTe−1=|∇Te|/Te electron temperature fluctuations are constant and above they steadily increase. Above the critical gradient, the electron heat flux inferred by power balance also increases rapidly. Critical gradients are a predicted attribute of turbulence arising from linear instabilities and are thought to be related to transport stiffness. The presented results are the first direct, systematic demonstration of critical gradient behavior in turbulence measurements in a tokamak. The experiment was performed by changing the deposition location of electron cyclotron heating shot-to-shot to locally scan LTe−1 at r/a = 0.6 in L-mode plasmas; rotation was also varied by changing the momentum input from neutral beam injection. Temperature fluctuations were measured with a correlation electron cy...