Two-Dimensional Spatial Structure of Plasma Turbulence in L MD-U

Introduction Recent progress in theoretical and experimental works on plasma turbulence has indicated that the micro turbulence tends to form spatiotemporal structures, which can either enhance or suppress the turbulent transport[1]. The structure formation in turbulent plasma, thus, is considered to be one of the most important issues to be clarified in the study of turbulence transport. The weak to strong turbulence transition is produced in the LMD-U device by controlling the strength and shape of the magnetic field and/or neutral pressure[2, 3]. To clarify the turbulence transition mechanism, an understanding of each state, i.e. the weak and strong turbulent state, is essential. For this purpose, this paper presents 2-dimensional structures of the electrostatic fluctuations observed in the weak turbulent plasmas.