Observation of Blobs and Holes in the Boundary Plasma of EAST Tokamak

Intermittent convective transport at the edge and in the scrape-off layer (SOL) of EAST was investigated by using fast reciprocating Langmuir probe. Holes, as part of plasma structures, were detected for the first time inside the shear layer. The amplitude probability distribution function of the turbulence is strongly skewed, with positive skewed events (“blobs”) prevailing in the SOL region and negative skewed events (“holes”) dominant inside the shear layer. The statistical properties coincide with previous observations from JET
Nuclear Fusion 49 (2009) 092002.. The generation mechanism of blobs and holes is also discussed. In addition burst structure and dynamics character of them are also presented.