Dynamics of energetic particle driven modes and MHD modes in wall-stabilized high beta plasmas on JT-60U and DIII-D

Matsunaga, Go; Okabayashi, Michio*; Aiba, Nobuyuki; Boedo, J. A.*; Ferron, J. R.*; Hanson, J. M.*; Hao, G. Z.*; Heidbrink, W. W.*; Holcomb, C. T.*; In, Y.*; Jackson, G. L.*; Liu, Y. Q.*; Luce, T. C.*; Mckee, G. R.*; Osborne, T. H.*; Pace, D. C.*; Shinohara, Koji; Snyder, P. B.*; Solomon, W. M.*; Strait, E. J.*; Turnbull, A. D.*; Van Zeeland, M. A.*; Watkins, J. G.*; Zeng, L.*; DIII-D Team*; JT-60 Team

In the wall-stabilized high- plasmas in JT-60U and DIII-D, interactions between energetic particle (EP) driven modes and MHD modes such as edge localized modes (ELMs) have been observed. The ELM triggering by EP driven modes (EPdMs) occurs when the repetition frequency of the EPdMs is higher than that of the ELM. The EPdMs have strong waveform distortion that is composed of higher toroidal harmonics. In particular, EP behavior seems to be sensitive to the waveform distortion, thus, waveform distortion can rapidly increase EP transport to edge. According to statistical analysis, the ELM triggering by the EPdMs infrequently occurs just after the ELM crash. Transported EPs by the EPdMs are thought to contribute to change the edge stability.