Observation and modelling of ion cyclotron range of frequencies waves in the mode conversion region of Alcator C-Mod
Observation and modelling of ion cyclotron range of frequencies waves in the mode conversion region of Alcator C-Mod
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DOI：
10.1088/0741-3335/47/8/005
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发表时间：
2005-08
影响因子：
2.2
通讯作者：
Y. Lin;S. Wukitch;A. Parisot;J. Wright;N. Basse;P. Bonoli;E. Edlund;L. Lin;M. Porkolab;G. Schilling;P. Phillips
中科院分区：
文献类型：
--
作者：
Y. Lin;S. Wukitch;A. Parisot;J. Wright;N. Basse;P. Bonoli;E. Edlund;L. Lin;M. Porkolab;G. Schilling;P. Phillips
在Alcator C-Mod的模式转换区观测到了快磁声波、模式转换离子回旋波（MC ICW）和模式转换离子伯恩斯坦波（MC IBW），并明确地识别出了它们的存在。在B 0 = 5.4T（fRF = 50 MHz）和B 0 = 8 T（fRF = 78 MHz）的D（3 He）等离子体中，研究了模式转换位置和Bpol/Btot。通过相位对比成像（PCI）系统测量RF波。实验观察的结果进行了比较，从一个合成的PCI诊断的基础上全波代码TORIC。在RF波的空间结构上，观测和建模之间取得了很好的一致性。当模式转换层离轴时，观察到MC ICW和MC IBW。在5.4T近轴模式转换放电中，实验观察到了MC波的双峰空间结构，并用合成PCI再现了这种双峰空间结构。这种结构是MC ICW的上下不对称性的指示。在8 T近轴模式转换放电中，我们首次在Alcator C-Mod中明确观察到IBW占主导地位的MC。
The fast magnetosonic wave, mode converted ion cyclotron wave (MC ICW) and mode converted ion Bernstein wave (MC IBW) have all been observed and unambiguously identified in the mode conversion region of Alcator C-Mod. The influences of the species mix, mode conversion location and Bpol/Btot have been studied in D(3He) plasmas at B0 ∼ 5.4 T (fRF = 50 MHz) and B0 ∼ 8 T (fRF = 78 MHz). The RF waves were measured by a phase contrast imaging (PCI) system. The experimental observation is compared with the result from a synthetic PCI diagnostic based upon the full wave code TORIC. Good agreement between the observation and modelling has been obtained on the spatial structure of the RF waves. When the mode conversion layer was off axis, both MC ICW and MC IBW were observed. In 5.4 T near-axis mode conversion discharges, the double hump spatial structure of the MC waves was observed experimentally and reproduced by the synthetic PCI. Such a structure is an indication of the up–down asymmetry of the MC ICW. In 8 T near-axis mode conversion discharges, we had the first definitive observation of IBW dominated MC in Alcator C-Mod.