Rigon G, Albertazzi B, Pikuz T, Mabey P, Bouffetier V, Ozaki N, Vinci T, Barbato F, Falize E, Inubushi Y, Kamimura N, Katagiri K, Makarov S, Manuel M J-E, Miyanishi K, Pikuz S, Poujade O, Sueda K, Togashi T, Umeda Y, Yabashi M, Yabuuchi T, Gregori G, Kodama R, Casner A, Koenig M
LULI, CNRS, CEA, École Polytechnique, UPMC, Univ Paris 06: Sorbonne Universités, Institut Polytechnique de Paris, F-91128 Palaiseau cedex, France.
Institute for Open and Transdisciplinary Research Initiative, Osaka University, Osaka, Japan.
Nat Commun. 2021 May 11;12(1):2679. doi: 10.1038/s41467-021-22891-w.
Turbulence is ubiquitous in the universe and in fluid dynamics. It influences a wide range of high energy density systems, from inertial confinement fusion to astrophysical-object evolution. Understanding this phenomenon is crucial, however, due to limitations in experimental and numerical methods in plasma systems, a complete description of the turbulent spectrum is still lacking. Here, we present the measurement of a turbulent spectrum down to micron scale in a laser-plasma experiment. We use an experimental platform, which couples a high power optical laser, an x-ray free-electron laser and a lithium fluoride crystal, to study the dynamics of a plasma flow with micrometric resolution (~1μm) over a large field of view (>1 mm). After the evolution of a Rayleigh-Taylor unstable system, we obtain spectra, which are overall consistent with existing turbulent theory, but present unexpected features. This work paves the way towards a better understanding of numerous systems, as it allows the direct comparison of experimental results, theory and numerical simulations.
湍流在宇宙和流体动力学中无处不在。它影响着从惯性约束聚变到天体物理对象演化等广泛的高能量密度系统。然而，由于等离子体系统中实验和数值方法的局限性，对湍流频谱进行完整描述仍然欠缺，因此了解这一现象至关重要。在此，我们展示了在激光等离子体实验中对直至微米尺度的湍流频谱的测量。我们使用了一个实验平台，该平台将高功率光学激光、X射线自由电子激光和氟化锂晶体相结合，以在大视场（>1毫米）上以微米级分辨率（约1μm）研究等离子体流的动力学。在瑞利 - 泰勒不稳定系统演化之后，我们获得了频谱，这些频谱总体上与现有湍流理论一致，但呈现出意想不到的特征。这项工作为更好地理解众多系统铺平了道路，因为它允许对实验结果、理论和数值模拟进行直接比较。
