Phase Diagram of Plasma Turbulence Structures

在磁场和充气压力的大范围工作参数下，我们表征了磁化等离子体中的湍流结构，并绘制了九州大学LMD-U等离子体状态相图。我们用多通道探针阵列观测了密度涨落谱。在充气压力和磁场的扫描空间中，发现了不同类型的光谱和分叉现象。此外，还分析了在分叉态之间的转变过程中的动力学。我们将频谱类型作为等离子体湍流特定状态的指标，并通过特征低频模式的幅度和总的双相干来量化这种状态。这项研究是非平衡体系相图展开的一个具体例子。

We characterized structures of turbulence in magnetized plasma for a wide range of operational parameters of magnetic field and filling gas pressure and made a phase diagram of plasma states in LMD-U at Kyushu University. We observed density fluctuation spectra with a multi-channel probe array. Different types of spectra and bifurcation phenomena were found in the scanned space of filling gas pressure and magnetic field. Furthermore, the dynamics during transitions between bifurcated states were analyzed. We considered the type of spectrum as an index of the specific state of plasma turbulence and quantified the state by amplitude and total bi-coherence of characteristic low frequency modes. This research is one concrete example of an expansion of the phase diagram in a non-equilibrium system.