The Impact of the current density profile on heat transport and pedestal structure in JT-60U

Urano, Hajime; Sakamoto, Yoshiteru; Suzuki, Takahiro; Fujita, Takaaki; Kamiya, Kensaku; Isayama, Akihiko; Kamada, Yutaka; Takenaga, Hidenobu; Oyama, Naoyuki; Matsunaga, Go; Ide, Shunsuke; Idomura, Yasuhiro   ; JT-60 Team

H-modes operated at higher with the current ramp down have shown higher energy confinement with higher density in JT-60U. The -factor evaluated for the core plasma depends strongly on with the relation of for the case without sawtooth activities. Center peaked profiles of electron density and electron temperature are obtained in high H-modes. The pedestal pressure is not significantly changed. The enhanced energy confinement in high H-modes is attributed to the core improvement with the peaked profiles of electron density and temperature. The electron heat diffusivity is reduced at the plasma core in high case, resulting in the center peaked profile while the profiles are approximately unchanged.