An intelligent identification method of the edge coherent mode in EAST

Abstract Edge Coherent Mode (ECM), a newly observed edge plasma behaviour in the Experimental Advanced Superconducting Tokamak (EAST), exhibits the potential for a new plasma-confinement regime for long-pulse discharge in future fusion devices. However, due to its intrinsically complex properties, e.g., inconstant shape, appearing area and occasionally overlapping with the broad spectrum turbulence, the intelligent identification of ECM turns out to be very challenging. In the present work, we propose an efficient and intelligent method to identify ECM in EAST by analyzing the row information points of the spectrogram, which is based on a two-step analysis: firstly, we estimate the difference of information points between adjacent rows as the horizontal feature of the analyzed spectrogram with ECM appearing. Secondly, the time interval of ECM is estimated as the vertical feature of the spectrogram. Such a method has been tested for 2000 different spectrograms and the correct rate of identification is 93.49%. The present work is expected to enhance the efficiency of data analysis in EAST with huge data base acquired from each discharge.