An upgraded electron cyclotron emission imaging (ECEI) system consisting of newoptics lenses with necessary electronics for receiving and processing signals for two dimension(2D) ECEI diagnostics was installed on EAST. Hyperboloid lens were adopted in the new systemto optimize the spatial resolutions. The mixers array of sixteen elements measured the plasmaelectron cyclotron emission at eight frequencies simultaneously, and the profiles of the electrontemperature and its fluctuation in an area of 20 cm (vertical) × 6 cm (horizontal) could then beanalyzed. Evolution of sawtooth precursor and crash in EAST was observed.
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