Accurate and stable measurements of edge density fluctuation with high spatio-temporal resolution have been achieved by the lithium beam emission spectroscopy(Li-BES)diagnostic on experimental and advanced superconducting tokamak(EAST).The new narrower band interference filter exhibits good ability to suppress background emission signal even under strong lithium coating of the tokamak.The raw data measured by channels at different spatial locations in avalanche photo diode camera with high chopping frequency show good consistency.Based on the detected experimental data,detailed information of density profile and fluctuation structures is obtained.A clear edge coherent mode in the auto-power spectrum is observed in pedestal region,which is regarded as the dominant factor for the strong pedestal density fluctuation amplitude.The cross-power spectrum analysis further excludes the additional effects of common-mode noises and non-local perturbation,demonstrating that the detected fluctuation is only caused by local density fluctuation.The normalized radial and poloidal wave-number spectra can specify the quantitative changes of radial wavenumber(kr)and poloidal wavenumber(kθ)during the pedestal density fluctuation phase.This new Li-BES system,which can provide more accurate experimental data,allows further studies of edge density fluctuation and complex transport process on EAST.

Donggui WU;Guanghai HU;S ZOLETNIK;Guosheng XU;Siye DING;Jianbin LIU;Linming SHAO;Yifeng WANG;Ran CHEN;Ning YAN;Yan CHAO;Ping WANG;D DUNAI;G ANDA;Liang CHEN;Liang WANG

Institute of Plasma Physics,Hefei Institutes of Physical Science,Chinese Academy of Sciences,Hefei 230031,People's Republic of China;University of Science and Technology of China,Hefei 230026,People's Republic of China;Centre for Energy Research,Budapest 1121,Hungary;Institute of Energy,Hefei Comprehensive National Science Center,Hefei 230031,People's Republic of China

等离子体科学和技术（英文版）

[1]Donggui WU;Guanghai HU;S ZOLETNIK;Guosheng XU;Siye DING;Jianbin LIU;Linming SHAO;Yifeng WANG;Ran CHEN;Ning YAN;Yan CHAO;Ping WANG;D DUNAI;G ANDA;Liang CHEN;Liang WANG-.Plasma edge density fluctuation measurements via lithium beam emission spectroscopy on EAST)[J].等离子体科学和技术（英文版）,2022(05):94-101

chopping

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