Multiple turbulent plasma states in the H-mode transition on JT-60U

Multiple turbulent plasma states in the edge transport barriers (ETBs) formation are studied on JT-60U. Following a slow L-H transition, which causes significant reduction in the ion thermal transport in the pedestal towards the neoclassical level with a weak negative Er value, a clear and fast changes in the particle transport in association was found with the change in the Er towards a strong negative value at the later H-phase. It has also been suggested that there is a clear difference in responses between ion and electron transports due to the change in the inhomogeneity in the Er. This observation suggests the presence of multiple types of turbulent fluctuations in the H-mode plasma state, which affects the ion energy and other channels of transport differently. The nonlinear dynamics that induce electric field bifurcation is also analysed. These analyses contribute to understanding of the L-H transition condition.