Interaction of coherent structures known as blobs in the scrape-off layer of magnetic confinement fusion devices is investigated. Isolated and interacting seeded blobs as well as full plasma turbulence are studied with a two dimensional fluid code. The features of the blobs (size, amplitude, position) are determined with a blob tracking algorithm, which identifies them as coherent structures above a chosen density threshold and compared to a conventional center of mass approach. The agreement of these two methods is shown to be affected by the parameters of the blob tracking algorithm. The benchmarked approach is then extended to a population of interacting plasma blobs with statistically distributed amplitudes, sizes and initial positions for different levels of intermittency. As expected, for decreasing intermittency, we observe an increasing number of blobs deviating from size-velocity scaling laws of perfectly isolated blobs. This is found to be caused by the interaction of blobs with the electrostatic potential of one another, leading to higher average blob velocities. The degree of variation from the picture of perfectly isolated blobs is quantified as a function of the average waiting time of the seeded blobs.

中文翻译：

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二维刮削层模拟中的斑点相互作用

研究了磁约束聚变装置的刮除层中称为斑点的相干结构的相互作用。使用二维流体代码研究孤立和相互作用的种子斑点以及完整的等离子体湍流。斑点的特征（大小、幅度、位置）由斑点跟踪算法确定，该算法将它们识别为高于所选密度阈值的相干结构，并与传统的质心方法进行比较。这两种方法的一致性被证明受 blob 跟踪算法参数的影响。然后将基准方法扩展到具有统计分布的振幅、大小和初始位置的不同间歇性水平的相互作用等离子体团的群体。正如预期的那样，为了减少间歇性，我们观察到越来越多的 blob 偏离了完全孤立 blob 的大小速度缩放定律。发现这是由斑点与彼此的静电势相互作用引起的，从而导致更高的平均斑点速度。完全隔离的斑点图片的变化程度被量化为种子斑点的平均等待时间的函数。