Dynamic between toroidal Alfvén eigenmode evolution and turbulence suppression under RMP on EAST

Since Alfve ́n activity and turbulence are ubiquitous in magnetically confined plasma, it is important to understand the possible roles of Alfve ́n activity on the nonlinear evolution of turbulence. Designed experiments in low collisionality are dedicated to studying the dynamic between turbulence and toroidal Alfvén eigenmodes (TAEs), and assessing the the multi-scale physics on the long-term scale behavior of fusion plasma. In TAEs (f\ ~\ 200\ kHz, n\ =\ 1) mitigation experiments under RMP (n_{upper}=2 and n_{lower}=3), there is a long-term (~500 ms) quasi-stationary state after RMP rapidly reduces the TAEs amplitude four times. Turbulence suppression and low-frequency zonal flows (LFZF) generation are observed in the period. Similar experiments show that energetic particles (EPs) may act an mediator of the cross-scale interactions and are beneficial for turbulence suppression and LFZF generation. Besides, the synchronous couplings of turbulence and TAEs, TAEs and LFZF are observed. The dynamic between turbulence and TAEs provides an idea for synchronous control of TAEs and turbulence. And the resulting EPs confinement improvement and T_e/T_i increase are favorable for plasma performance.