Hillesheim J C, DeBoo J C, Peebles W A, Carter T A, Wang G, Rhodes T L, Schmitz L, McKee G R, Yan Z, Staebler G M, Burrell K H, Doyle E J, Holland C, Petty C C, Smith S P, White A E, Zeng L
Department of Physics and Astronomy, University of California at Los Angeles, Los Angeles, California 90024-1547, USA.
General Atomics, San Diego, California 92186-5608, USA.
Phys Rev Lett. 2013 Jan 25;110(4):045003. doi: 10.1103/PhysRevLett.110.045003. Epub 2013 Jan 23.
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.
在一项针对受限高温等离子体核心局部测量的湍流量进行的系统、受控实验中，首次观测到了一个临界梯度阈值。在DIII-D托卡马克装置的一项实验中，当改变L(T(e))(-1)=|∇T(e)|/T(e)和环向旋转时，长波长(k(θ)ρ(s)≲0.4)电子温度涨落在L(T(e))(-1)中呈现出一个阈值：低于该阈值时，它们变化很小；高于该阈值时，它们则稳步增加。δT(e)/T(e)的增加与电子热通量和输运刚度的增加同时出现。观测结果对旋转不敏感。累积的证据有力地支持了将实验观测到的阈值与∇T(e)驱动的俘获电子模湍流相识别。
