Edge-coherent-mode nature of the small edge localized modes in Experimental Advanced Superconducting Tokamak
Edge-coherent-mode nature of the small edge localized modes in Experimental Advanced Superconducting Tokamak
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DOI：
10.1063/1.4896237
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发表时间：
2014-09
影响因子：
2.2
通讯作者：
Huiqian Wang;Gang Xu;Houyang Y Guo;B. Wan;L. Wang;Rende Chen;S. Ding;N. Yan;X. Gong;Shaocheng Liu;L. Shao;Longwei Chen;Wei Zhang;Y. Liang;G. Hu;Y. Liu;Yingying Li;N. Zhao
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文献类型：
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作者：
Huiqian Wang;Gang Xu;Houyang Y Guo;B. Wan;L. Wang;Rende Chen;S. Ding;N. Yan;X. Gong;Shaocheng Liu;L. Shao;Longwei Chen;Wei Zhang;Y. Liang;G. Hu;Y. Liu;Yingying Li;N. Zhao
在实验先进超导托卡马克装置上，采用低杂波电流驱动和离子回旋共振加热加锂壁调节，实现了高频低能损耗小边缘局域模（ELMs）的高约束区。小ELMs通常伴随着准相干模式在30 kHz左右的频率，检测到的朗缪尔探针附近的分界线。相干模在实验室坐标系中沿电子抗磁漂移方向传播，极向波长λθ <$14 cm，对应于高的极向和环向模数（m > 60，n > 12），具有不同于传统ELMs的弱磁扰动。这种相干模式，携带高温高密度的类超导等离子体，驱动相当大的运输从基座区域到刮落层朝向偏滤器区域。小ELMs和准相干模的共存有利于长脉冲H模的维持，而不会产生明显的约束退化。
High-confinement regime with high-frequency and low-energy-loss small edge localized modes (ELMs) was achieved in Experimental Advanced Superconducting Tokamak by using the lower hybrid current drive and ion cyclotron resonance heating with lithium wall conditioning. The small ELMs are usually accompanied with a quasi-coherent mode at frequency around 30 kHz, as detected by the Langmuir probes near the separatrix. The coherent mode, with weak magnetic perturbations different from the precursor of conventional ELMs, propagates in the electron diamagnetic drift direction in the lab frame with the poloidal wavelength λθ ∼ 14 cm, corresponding to both high poloidal and toroidal mode numbers (m > 60 and n > 12). This coherent mode, carrying high-temperature high-density filament-like plasma, drives considerable transport from the pedestal region into the scrape-off layer towards divertor region. The co-existence of small ELMs and quasi-coherent modes is beneficial for the sustainment of long pulse H-mode regime without significant confinement degradation.