Experimental and simulation analysis of Weakly Coherent Modes in I-mode discharges on EAST

• DOI: 10.1088/1741-4326/ad4b3f
• Publication Date: 2024-05-14T22:25:03Z
• Authors: Y.J. Liu; Z.X. Liu; T.Y. Xia; T. Zhang; A.D. Liu; J. Liu; C.C. Deng; K.X. Ye; K.N. Geng; G.S. Li; F.F. Long; J.Y. Li; P.C. Li; K.N. Yang; Q. Zang; A. Ti; H.L. Zhao; H.Q. Liu; H. Li; J.L. Xie; T. Lan; W.Z. Mao; C. Zhou; W.X. Ding; G. Zhuang; W.D. Liu; G.Q. Li; X. Gao
• Keywords: Wavenumber

Abstract This paper reports the recent observation of a weakly coherent mode (WCM) within conventional reflectometer on EAST and successfully determines its poloidal wavenumber range. During transition from L-mode to I-mode, line-averaged density remains nearly unchanged while significant change is observed in electron cyclotron emission (ECE) signals at boundary. The difference between for two channels edge increased, coinciding with appearance WCM simultaneous rise boundary temperature. Further investigation unveiled modulating role temperature ring oscillation (ETRO) (Liu et al 2020 Nucl. Fusion 60 126016) high-frequency fluctuations. Statistical results unveil an inverse relationship centeral frequency q 95 . Simulation provide additional insights, demonstrating that simulated ‘WCM’ fluctuations aligns experimental data terms center frequency. Additionally, radial distribution closely corresponds regions strongest gradients. Finally, through cross-correlation analysis fluctuations, following phase range was observed: <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi>α</mml:mi> <mml:mover> <mml:mi>T</mml:mi> <mml:mo>~</mml:mo> </mml:mover> </mml:mrow> <mml:mi>e</mml:mi> </mml:msub> <mml:mo>&gt;</mml:mo> <mml:mi>n</mml:mi> <mml:mi>i</mml:mi> <mml:mo>∼</mml:mo> <mml:mi>ϕ</mml:mi> </mml:math>