Turbulent edge transport in the Princeton Beta Experiment‐Modified high confinement mode
Turbulent edge transport in the Princeton Beta Experiment‐Modified high confinement mode
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DOI：
10.1063/1.870916
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发表时间：
1994-10
影响因子：
2.2
通讯作者：
G. Tynan;L. Schmitz;L. Blush;J. Boedo;R. Conn;R. Doerner;R. Lehmer;R. Moyer;H. Kugel;R. Bell;S. Kaye;M. Okabayashi;S. Sesnic;Y. Sun
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文献类型：
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作者：
G. Tynan;L. Schmitz;L. Blush;J. Boedo;R. Conn;R. Doerner;R. Lehmer;R. Moyer;H. Kugel;R. Bell;S. Kaye;M. Okabayashi;S. Sesnic;Y. Sun
报道了首次探测中性光束诱导的高约束模式(H模)中的边缘湍流和输运。在H模中直接观测到一个很强的负径向电场。在低禁闭模式到高禁闭模式(L-H)的跃迁过程中，归一化离子饱和能级和浮动势涨落能级被瞬时抑制，然后恢复到接近低模(L模式)的能级。平均极向波数和极向波数谱宽减小，脉动密度与势能的相关性减小。在H模中观察到局域为强径向电场的大幅度相干振荡，但不引起输运。在H型模式下，有效湍流扩散系数在最后一个闭合通量面内和刮除层内减小了一个数量级。并将计算结果与速度剪切稳定化抑制湍流的启发式模型进行了比较。
The first probe measurements of edge turbulence and transport in a neutral beam induced high confinement mode (H‐mode) are reported. A strong negative radial electric field is directly observed in H‐mode. A transient suppression of normalized ion saturation and floating potential fluctuation levels occurs at the low confinement mode to high confinement mode (L–H) transition, followed by a recovery to near low mode (L‐mode) levels. The average poloidal wave number and the poloidal wave‐number spectral width are decreased, and the correlation between fluctuating density and potential is reduced. A large‐amplitude coherent oscillation, localized to the strong radial electric field region, is observed in H‐mode but does not cause transport. In H‐mode the effective turbulent diffusion coefficient is reduced by an order of magnitude inside the last closed flux surface and in the scrape‐off layer. The results are compared with a heuristic model of turbulence suppression by velocity‐shear stabilization.