Experimental study of quasi-coherent mode using EAST tangential CO 2 laser collective scattering diagnostic in far-forward mode
Experimental study of quasi-coherent mode using EAST tangential CO 2 laser collective scattering diagnostic in far-forward mode
复制标题
远前模式EAST切向CO 2 激光集体散射诊断准相干模式实验研究
DOI：
10.1063/1.5049209
复制
发表时间：
2019
影响因子：
2.2
通讯作者：
吴国将
中科院分区：
文献类型：
--
作者：
孙鹏军;李亚东;任扬;张晓东;吴国将
在实验先进超导托卡马克（EAST）装置上，利用切向CO2激光集体散射诊断技术，在高等离子体电子密度下，在增强D a /小边缘局域模（ELM）和无ELM H模阶段，测量了准相干模（QCM）。仅用本振CO2激光散射的实验结果证明了在远场模式下用散射诊断法测量QCM是可行的。驱动QCM密度涨落（k？< 3厘米？1）和磁场涨落的关系表明QCM是一种电磁模。QCM的典型频率为f？26.5kHz.散射信号和Mirnov信号的组合分析表明，QCM具有环形模数n？17并且沿着实验室坐标系中的电子抗磁漂移速度方向旋转。对Mirnov信号和反射计信号的分析支持QCM位于边缘基座区的观点。QCM功率与D-a信号和基座密度梯度有关。详细地比较了EAST QCM和C-Mod准相干模。
A quasi-coherent mode (QCM) was measured by the tangential CO 2 laser collective scattering diagnostic at high plasma electron.density during both enhanced D a /small edge-localized mode (ELM) and ELM-free H mode phases in Experimental Advanced.Superconducting Tokamak (EAST). Experimental results from only local oscillator CO 2 laser scattering prove that the QCM is.measured by the scattering diagnostic in the far-forward mode. The driven QCM density fluctuation (k ? < 3 cm ?1 ) and magnetic.fluctuation suggest that the QCM is an electromagnetic mode. The typical frequency of the QCM is f?26.5kHz. A combination.analysis of scattering signals and Mirnov signals suggests that the QCM has toroidal mode number n?17 and rotates along with.the electron diamagnetic drift velocity direction in the lab frame. The analysis of Mirnov and reflectometer signals supports that.the QCM locates in the edge pedestal region. The QCM power has been found to be related to both the D a signal and the pedestal.density gradient. A comparison of the EAST QCM and C-Mod quasi-coherent mode has been given in detail.