Observation of a critical gradient threshold for electron temperature fluctuations in the DIII-D Tokamak.
Observation of a critical gradient threshold for electron temperature fluctuations in the DIII-D Tokamak.
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DOI：
10.1103/physrevlett.110.045003
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发表时间：
2012-10
影响因子：
8.6
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
在一项系统的、受控的实验中，首次观察到临界梯度阈值，该实验针对受限高温等离子体核心中局部测量的湍流量。在 DIII-D 托卡马克实验中，L(T(e))(-1) = |∇T(e)|/T(e) 和环形旋转发生变化，长波长 (k(θ)ρ(s) ≲ 0.4) 电子温度波动在 L(T(e))(-1) 中表现出阈值：低于，它们变化很小；上面，它们稳步增加。 δT(e)/T(e) 的增加与电子热通量和传输刚度的增加同时发生。观察结果对旋转不敏感。积累的证据有力地证明了通过 ∇T(e) 驱动的俘获电子模式湍流实验观察到的阈值的识别。
A critical gradient threshold has been observed for the first time in a systematic, controlled experiment for a locally measured turbulent quantity in the core of a confined high-temperature plasma. In an experiment in the DIII-D tokamak where L(T(e))(-1) = |∇T(e)|/T(e) and toroidal rotation were varied, long wavelength (k(θ)ρ(s) ≲ 0.4) electron temperature fluctuations exhibit a threshold in L(T(e))(-1): below, they change little; above, they steadily increase. The increase in δT(e)/T(e) is concurrent with increased electron heat flux and transport stiffness. Observations were insensitive to rotation. Accumulated evidence strongly enforces the identification of the experimentally observed threshold with ∇T(e)-driven trapped electron mode turbulence.