The impact of electromagnetic effects on macroscopic dynamics of blobs in hot low-β ( β < m e / m i) edge plasma of fusion devices is analyzed. The physical model governing filament dynamics is presented. The qualitative analysis of the blob motion in electrostatic and electromagnetic regimes is performed. The scalings for the plasma potential and filament advection velocity are obtained along with the estimates of plasma parameters, for which the physics of Alfven waves and skin effect can have an impact on the filament motion. It is shown that required edge/scrape-off layer conditions can be found in modern tokamaks. Analytical expressions for the distributions of the parallel current and electrostatic potential in a blob, containing electrostatic and electromagnetic contributions, are derived. It is demonstrated that in sufficiently hot, weakly resistive plasma the electromagnetic effects can lead to noticeable variations of the potential along the magnetic field lines distorting the blob propagation pattern in contrast to the electrostatic case. Results of the theoretical analysis are compared with results of 3D BOUT++ modeling, which show that in the electromagnetic limit, the macroscopic motion of blobs can exhibit ballooning features due to the emission of Alfven waves, absent in electrostatic simulations. It is concluded that, at least in the near scrape-off layer region of fusion devices, electromagnetic models of plasma dynamics may be appropriate for the analysis of blob motion instead of electrostatic ones.

中文翻译：

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电磁效应对聚变装置热低β边缘等离子体中斑点宏观动力学的影响

分析了电磁效应对聚变装置热低β（β<me/mi）边缘等离子体中斑点宏观动力学的影响。介绍了控制灯丝动力学的物理模型。对静电和电磁区域中的斑点运动进行了定性分析。等离子体电位和灯丝平流速度的标度与等离子体参数的估计一起获得，对于这些参数，阿尔文波的物理特性和趋肤效应会对灯丝运动产生影响。结果表明，在现代托卡马克装置中可以找到所需的边缘/刮削层条件。导出了包含静电和电磁贡献的 blob 中并联电流和静电势分布的解析表达式。证明在足够热的情况下，在弱电阻等离子体中，与静电情况相比，电磁效应会导致沿磁场线的电势发生显着变化，从而扭曲斑点传播模式。将理论分析的结果与 3D BOUT++ 建模的结果进行比较，结果表明，在电磁极限下，由于阿尔文波的发射，斑点的宏观运动可以表现出膨胀特征，而静电模拟中则没有。得出的结论是，至少在聚变装置的接近刮削层区域，等离子体动力学的电磁模型可能适用于分析斑点运动而不是静电模型。