Study on divertor heat flux under n = 3 and n = 4 resonant magnetic perturbations using infrared thermography diagnostic in EAST

Abstract

Resonant magnetic perturbations (RMPs) with high toroidal mode number n are considered for controlling edge-localized modes (ELMs) and divertor heat flux in future ITER H-mode operations. In this paper, characteristics of divertor heat flux under high-n RMPs (n = 3 and 4) in H-mode plasma are investigated using newly upgraded infrared thermography diagnostic in EAST. Additional splitting strike point (SSP) accompanying with ELM suppression is observed under both RMPs with n = 3 and n = 4, the SSP in heat flux profile agrees qualitatively with the modeled magnetic footprint. Although RMPs suppress ELMs, they increase the stationary heat flux during ELM suppression. The dependence of heat flux on during ELM suppression is preliminarily investigated, and further splitting in the original strike point is observed at during ELM suppression. In terms of ELM pulses, the presence of RMPs shows little influence on transient heat flux distribution.