Reverse-sheared Alfvén eigenmodes(RSAEs) have been observed by using an interferometer and ECE diagnostics in NBI heated ELMy H-mode plasma on EAST tokamak. A typical feature of these modes is a fast frequency sweeping upward from ～80 kHz to ～110 kHz in hundred milliseconds during which the plasma temperature, density and rotation keeps no change. Only core channels of the interferometer can observe these modes, implying a core localized mode. The ECE measurement further showed that these modes located at aboutρ?=?0.37–0.46, just around the position of q_(min)with ρ?～?0.4. These core localized modes are very weak in the magnetic fluctuations measured by mirnov probes mounted at the machine vacuum vessel. A multiple frequency fluctuation component, seemingly the so-called ‘grand cascades', was also clearly observed on the ECE signal at ρ?=?0.46. During the phase, a transient internal transport barrier(ITB) in ion temperature and toroidal rotation was observed and the ITB foot was just close to the position of q_(min). A modulation of RSAE frequency by ELM event was observed and this modulation could be attributed to rotation decrease or q_(min)increase due to ELM. Further study of these modes in EAST can provide valuable constraints for the q profile measurement and will be important for the long pulse operation.
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