Coherent modes and turbulences observations with multi-channel Doppler reflectometer on experimental advanced superconducting tokamak

摘要

With a newly installed 5-channel W-band Doppler reflectometer (DR) in EAST tokamak, many interesting coherence modes and turbulences have been observed. In this paper, the tearing mode (TM), a novel inter-edge localized mode (ELM) electromagnetic mode, and the eigenmode geodesic acoustic mode (GAM) accompanied by a broadband quasi-coherent mode (QCM) during H-mode stage have been reported. The TM could be directly observed in both density fluctuation and perpendicular velocity fluctuation at the DR channel localized in the magnetic island region; moreover, many high-order TM frequency harmonics, dual turbulence peaks inside and outside the island separatrix, and strong flow shear across the island separatrix could also be observed. A high-frequency (