Non-dimensional transport study on ELMy H-mode plasmas in JT-60U

Non-dimensional transport studies have been carried out for NBI heated ELMy II-mode plasmas in JT-60U. In a high-delta (triangularity) case, both the electron thermal diffusivity, chi (e), and the ion thermal diffusivity, chi (i), show gyroBohm-like diffusion, chi (e)/chi (Bohm), chi (i)/chi Bohm proportional to (rho*)(0.7-0.9) where rho* is the normalized Larmor radius. The dependence of the energy confinement on the normalized collision frequency, v*, was also studied. The weak nu* dependence of the energy confinement time, tau (E)/tau (Bohm) proportional to (1/nu*)(similar to0.3), was also obtained in the high-delta case. On the assumption of the same nu* dependence of tau (E)/tau (Bohm), the rho* dependence of chi* in the low-delta case is compatible with the high-delta vase. When the ELM activity is strong enough to affect the global energy confinement, however, the ion energy confinement was significantly degraded, although the electron energy confinement still follows the gyroBohm-like diffusion.