Study of turbulence modulation and core density peaking with CO 2 laser collective scattering diagnostics in EAST tokamak

We report experiments designed to help us understand the interaction between electron-scale turbulence and plasma poloidal flow in tokamaks. Multiple electron-scale turbulence (for 0.8 <= k theta rho s <= 4/ne <(0.5) >) can be obtained. We note that the intensity of turbulence and the core density peaking factor show a negative correlation, while the poloidal rotation speed is inversely proportional to the intensity of electron-scale turbulence. The correlation between turbulence and plasma flow is found to be closely related to the density peaking factor. The quasi-linear theory of electron-scale turbulence-driven intrinsic poloidal rotation is adopted, and it shows that plasma flow may exhaust the free energy of turbulence through Reynolds stress. Besides, by comparing the plasma flow shear and spatial cross-correlation of turbulence we observed that the spatial structure of turbulence at k theta=12cm-1k theta=22cm-1More