First evidence of the role of zonal flows for the L-H transition at marginal input power in the EAST tokamak.
First evidence of the role of zonal flows for the L-H transition at marginal input power in the EAST tokamak.
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DOI：
10.1103/physrevlett.107.125001
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发表时间：
2011-09
影响因子：
8.6
通讯作者：
Gang Xu;B. Wan;Huiqian Wang;Houyang Guo;Houyang Guo;H. Zhao;A. Liu;Volker Naulin;Patrick H Diamond;G. Tynan;Min Xu;R. Chen;M. Jiang;P. Liu;Ning Yan;Wei Zhang;L. Wang;Shaocheng Liu;Siye Ding
中科院分区：
文献类型：
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作者：
Gang Xu;B. Wan;Huiqian Wang;Houyang Guo;Houyang Guo;H. Zhao;A. Liu;Volker Naulin;Patrick H Diamond;G. Tynan;Min Xu;R. Chen;M. Jiang;P. Liu;Ning Yan;Wei Zhang;L. Wang;Shaocheng Liu;Siye Ding
在EAST托卡马克装置上，利用两个环形分离的往复探针，首次观测到了频率小于4kHz的准周期Er振荡，其频率远低于测地线声学模的频率，且在低-高约束模跃迁前后，边缘湍流都有调制。在L-H跃迁之前，Er振荡经常演变成间歇性的负Er尖峰。低频Er振荡，以及Er尖峰，是强烈相关的连续性驱动的雷诺应力，从而提供了第一个证据的纬向流的作用在L-H过渡在边际输入功率。这些新发现不仅揭示了L-H跃迁的物理机制，而且对ITER在L-H跃迁阈值功率附近的运行具有重要意义。
A quasiperiodic Er oscillation at a frequency of <4 kHz, much lower than the geodesic-acoustic-mode frequency, with a modulation in edge turbulence preceding and following the low-to-high (L-H) confinement mode transition, has been observed for the first time in the EAST tokamak, using two toroidally separated reciprocating probes. Just prior to the L-H transition, the Er oscillation often evolves into intermittent negative Er spikes. The low-frequency Er oscillation, as well as the Er spikes, is strongly correlated with the turbulence-driven Reynolds stress, thus providing first evidence of the role of the zonal flows in the L-H transition at marginal input power. These new findings not only shed light on the underlying physics mechanism for the L-H transition, but also have significant implications for ITER operations close to the L-H transition threshold power.