Plasma turbulence is investigated using unprecedented high-resolution ion velocity distribution measurements by the Magnetospheric Multiscale mission (MMS) in the Earth’s magnetosheath. This novel observation of a highly structured particle distribution suggests a cascadelike process in velocity space. Complex velocity space structure is investigated using a three-dimensional Hermite transform, revealing, for the first time in observational data, a power-law distribution of moments. In analogy to hydrodynamics, a Kolmogorov approach leads directly to a range of predictions for this phase-space transport. The scaling theory is found to be in agreement with observations. The combined use of state-of-the-art MMS data sets, novel implementation of a Hermite transform method, and scaling theory of the velocity cascade opens new pathways to the understanding of plasma turbulence and the crucial velocity space features that lead to dissipation in plasmas.

中文翻译：

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等离子体速度-空间级联的磁层多尺度观测：厄米表示和理论

利用磁悬浮层多尺度任务（MMS）在地球磁石场中利用空前的高分辨率离子速度分布测量研究了等离子体湍流。这种对高度结构化的粒子分布的新颖观察表明，在速度空间中有一个级联过程。使用三维Hermite变换研究了复杂的速度空间结构，首次在观测数据中揭示了矩的幂律分布。与流体动力学类似，Kolmogorov方法直接导致了对该相空间传输的一系列预测。发现缩放理论与观察结果一致。结合使用最新的MMS数据集，Hermite转换方法的新颖实现，