Effect of core pressure gradient just inside the top of the pedestal on the energy loss due to the edge localized mode in JT-60U

Hayashi, Nobuhiko; Oyama, Naoyuki; Takizuka, Tomonori; Aiba, Nobuyuki; Ozeki, Takahisa

The effect of core pressure gradient just inside the top of the pedestal on the energy loss due to type-I edge localized modes (ELMs) has been studied. The analysis of the experimental data from JT-60U shows that the ELM energy loss increases with the pressure gradient inside the pedestal. The dependence of ELM energy loss on the pressure gradient inside the pedestal is similar to that predicted by the integrated code TOPICS-IB. The stability of linear ideal MHD modes is analyzed by using experimental profiles. It is found that the steep core pressure gradient inside the pedestal broadens inward eigenfunction profiles of unstable modes. The TOPICS-IB simulation predicted that this broadening can enhance the ELM energy loss.