Author(s): DING Baogang, WU Jun, FAN Weiwei, WU Tongyu, ZHOU Yan, YIN Zejie, State Key Laboratory of Particle Detection and Electronics, University of Science and Technology of China, Department of Modern Physics, University of Science and Technology of China, Shanghai Radio Equipment Institute, Southwestern Institute of Physics
Pages: 1092-1096
Year: 2015 Issue:  12
Journal: Plasma Science and Technology
Keyword:  RDSA; phase difference; real-time; electron density; Faraday rotation angle;
Abstract: Electron density and Faraday rotation angle are important physical parameters in nuclear fusion research.To measure them simultaneously,the three-wave polarimeter/interferometer diagnostic system is applied.Both the final probe output signal and the reference signal contain three frequency components.The time-varying phase difference curve of each frequency component can be measured by the Real-time Dynamic Spectrum Analysis(RDSA)method based on Field-Programmable Gate Array(FPGA).The phase difference precision is better than 0.1° and the real-time feedback delay is less than 1 ms,which satisfy the requirements of HL-2A.