Study of Striated Heat Flux on EAST Divertor Plates Induced by LHW Using Infrared Camera

An upgraded infrared (IR) imaging system which provides a wide field of view (FOV) has been installed on the Experimental Advanced Superconducting Tokamak (EAST) to monitor the surface temperatures on plasma facing components. Modified magnetic topology induced by lower hybrid wave (LHW) can lead to the formation of striated heat flux (SHF) on divertor plates which can be clearly observed by IR camera. In this paper, LHW power modulation is applied to analyze the appearance of SHF. It is also demonstrated that deuterium (D) pellet injection and supersonic molecular beam injection (SMBI) can to some extent reduce the heat flux on the outer strike point (OSP), but enhance the SHF on lower outer plates (LOP) of divertor. This may provide an optional approach to actively control the distribution of heat flux on diveror plates, which can protect materials from long duration high-heat flux.