Effect of island overlap on edge localized mode suppression by resonant magnetic perturbations in DIII-D
Effect of island overlap on edge localized mode suppression by resonant magnetic perturbations in DIII-D
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DOI：
10.1063/1.2901064
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发表时间：
2008-05
影响因子：
2.2
通讯作者：
M. Fenstermacher;T. Evans;T. Osborne;M. Schaffer;M. Aldan;J. Degrassie;P. Gohil;I. Joseph;R. M
中科院分区：
文献类型：
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作者：
M. Fenstermacher;T. Evans;T. Osborne;M. Schaffer;M. Aldan;J. Degrassie;P. Gohil;I. Joseph;R. M
[J]。L. Luxon等人，核。聚变43,1813(2003)]实验表明，微扰线圈在边缘等离子体中诱导的磁岛重叠程度与具有类似iter的电子座碰撞νe* ~ 0.1、磁面形状和低边缘安全系数（q95≈3.6）的等离子体中i型边缘局域模式（elm）的完全抑制之间存在相关性。在固定幅值n=3的共振磁扰动（RMP）下，仅在边缘安全系数（q95）的有限窗口内获得ELM抑制，该窗口与所施加螺旋场的谐振分量最大化相一致。通过增加n=3 RMP强度，或通过添加n=1扰动来“填补”边缘等离子体岛屿之间的间隙，可以在q95的增加范围内获得ELM抑制。基于排除等离子体响应的RMP模分量的真空计算，i型ELMs的抑制与具有奇里科夫参数>1.0的磁岛边缘区域的最小宽度相关。
Recent DIII-D [J. L. Luxon et al., Nucl. Fusion 43, 1813 (2003)] experiments show a correlation between the extent of overlap of magnetic islands induced in the edge plasma by perturbation coils and complete suppression of Type-I edge localized modes (ELMs) in plasmas with ITER-like electron pedestal collisionality νe*∼0.1, flux surface shape and low edge safety factor (q95≈3.6). With fixed amplitude n=3 resonant magnetic perturbation (RMP), ELM suppression is obtained only in a finite window in the edge safety factor (q95) consistent with maximizing the resonant component of the applied helical field. ELM suppression is obtained over an increasing range of q95 by either increasing the n=3 RMP strength, or by adding n=1 perturbations to “fill in” gaps between islands across the edge plasma. The suppression of Type-I ELMs correlates with a minimum width of the edge region having magnetic islands with Chirikov parameter >1.0, based on vacuum calculations of RMP mode components excluding the plasma response ...