Measurement of small island characteristics using high resolution ECE and CER at DIII-D

IF 2.1 2区物理与天体物理 Q2 PHYSICS, FLUIDS & PLASMAS

Plasma Physics and Controlled Fusion Pub Date : 2024-09-09 DOI:10.1088/1361-6587/ad75b8

J Yang, E D Fredrickson, Q Hu, M Podestà, J W Berkery, L Bardóczi, R J La Haye, O Sauter, M Austin, E Strait and C Chrystal

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Abstract

The measurements using the high resolution electron cyclotron emission radiometry and the charge exchange and recombination spectroscopy are processed using analytic formulas to allow for the detection of islands as small as 1.9 cm. In contrast to large, saturated magnetic islands which are relatively well understood to be governed by the loss of bootstrap current inside the island, small islands are less well understood due to the difficulty of their accurate measurement in tokamaks. Here, ‘small’ islands are islands comparable in size to the ion banana width, which can be as small as 0.8 cm at DIII-D. The new measurement methods allow for the detection of small island widths when the predicted increase of mode frequency to match the Doppler shifted ion diamagnetic frequency is observed. Therefore, for the first time, the mode frequency increase can be unambiguously associated to the acceleration of the magnetic island propagation. Such association allows for a further development and validation of the much-debated theory of ion polarization currents, which is thought to govern the small island growth.

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利用 DIII-D 高分辨率欧洲经委会和欧洲辐射计测量小岛屿特性

利用高分辨率电子回旋发射辐射测量法和电荷交换与重组光谱法进行的测量是通过分析公式处理的，从而能够探测到小至 1.9 厘米的磁岛。与大型饱和磁岛相比，人们对磁岛内部自举电流损耗的了解相对较多，而对小岛的了解则较少，因为在托卡马克中很难对其进行精确测量。在这里，"小岛 "是指大小与离子蕉宽度相当的岛屿，在 DIII-D 中可以小到 0.8 厘米。新的测量方法可以在观测到与多普勒偏移离子二磁频率相匹配的模式频率预测增加时，检测到小的岛宽度。因此，第一次可以明确地将模式频率的增加与磁岛传播的加速联系起来。这种关联使人们能够进一步发展和验证备受争议的离子极化电流理论，该理论被认为是控制磁岛增长的因素。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Plasma Physics and Controlled Fusion 物理-物理：核物理

CiteScore

4.50

自引率

13.60%

发文量

224

审稿时长

4.5 months

期刊介绍： Plasma Physics and Controlled Fusion covers all aspects of the physics of hot, highly ionised plasmas. This includes results of current experimental and theoretical research on all aspects of the physics of high-temperature plasmas and of controlled nuclear fusion, including the basic phenomena in highly-ionised gases in the laboratory, in the ionosphere and in space, in magnetic-confinement and inertial-confinement fusion as well as related diagnostic methods. Papers with a technological emphasis, for example in such topics as plasma control, fusion technology and diagnostics, are welcomed when the plasma physics is an integral part of the paper or when the technology is unique to plasma applications or new to the field of plasma physics. Papers on dusty plasma physics are welcome when there is a clear relevance to fusion.