ELM propagation and fluctuations characteristics in H- and L-mode SOL plasmas on JT-60U

Asakura, Nobuyuki; Ono, Noriyasu*; Kawashima, Hisato; Miyoshi, Hideaki*; Matsunaga, Go; Oyama, Naoyuki; Takamura, Shuichi*; Uesugi, Yoshihiko*; Takechi, Manabu; Nakano, Tomohide; et al.

Proceedings of 21st IAEA Fusion Energy Conference (FEC 2006) (CD-ROM), 8 Pages, 2007/03

http://www-naweb.iaea.org/napc/physics/FEC/FEC2006/html/node414.htm#82494

Radial transport of the SOL plasma was recently studied in order to understand heat and particle loading to the first wall and the SOL formation mechanism. Fast propagation of the ELM plasma and fluctuation properties in H- and L-modes were determined at low-field-side (LFS) SOL using reciprocating Mach probes in JT-60U. Large and short peaks were found in ELM plasma flux, which was regularly enhanced after each ELM event. Transport dynamics of the first large peak was determined, i.e. it propagated to near the first wall with the fast velocity of 1.3-2.5 km/s. Statistical analysis of a probability distribution function was applied to describe intermittent (non-diffusion) transport in SOL plasma fluctuations. It was found that the positive bursty events appeared in a wide SOL region, where the flow reversal of the SOL plasma was observed. Influences of the radial transport of the convective blobby plasma on the SOL formation and the flow reversal were investigated.