An experimental investigation of blob behaviors in lower hybrid wave dominant heating scenarios on EAST

Systematic measurements on scrape-off layer (SOL) blob behaviors have been performed by lithium beam emission spectroscopy on EAST in lower hybrid wave (LHW) heating dominant low confinement (L-mode) discharges. With the application of LHW, blob fluctuation amplitude and associated blob radial transport flux are profoundly suppressed. The reductions of the blob amplitude and transport flux are concomitant with the increase of SOL poloidal velocity and E r × B flow shear. Meanwhile, the blob eddy is strongly tilted and the radial correlation length is reduced. All the measurements point toward the important influences of the LHW induced Doppler shift effect and E r × B flow shear on the suppression of blobs and low frequency turbulence.Systematic measurements on scrape-off layer (SOL) blob behaviors have been performed by lithium beam emission spectroscopy on EAST in lower hybrid wave (LHW) heating dominant low confinement (L-mode) discharges. With the application of LHW, blob fluctuation amplitude and associated blob radial transport flux are profoundly suppressed. The reductions of the blob amplitude and transport flux are concomitant with the increase of SOL poloidal velocity and E r × B flow shear. Meanwhile, the blob eddy is strongly tilted and the radial correlation length is reduced. All the measurements point toward the important influences of the LHW induced Doppler shift effect and E r × B flow shear on the suppression of blobs and low frequency turbulence.