Speaker
Dr
Yuan Yao
(Institute of Plasma Physics, Chinese Academy of Sciences)
Description
The far-infrared laser-based HCN interferometer and POlarimeter/INTerferometer (POINT) system are important diagnostics for plasma density measurement on EAST tokamak. Both HCN and POINT provide high spatial and temporal resolution of electron density measurement and used for plasma density feedback control. The density is calculated by measuring the real-time phase difference between the reference beams and the probe beams. For long-pulse operations on EAST, the calculation of density has to meet the requirement of Real-Time and high precision.
In this paper, a Phasemeter for far-infrared laser-based interferometers will be introduced. The FPGA-based Phasemeter leverages fast ADCs to obtain the three-frequency signal from VDI planar-diode Mixers, and realizes digital filters and an FFT algorithm in FPGA to provide real-time, high precision electron density output. The implementation of the Phasemeter will be helpful for the future plasma real-time feedback control in long-pulse discharge.
Primary author
Dr
Yuan Yao
(Institute of Plasma Physics, Chinese Academy of Sciences)
Co-authors
Prof.
Haiqing Liu
(ASIPP)
Hui Lian
(University of Science and Technology of China)
Mr
Weiming Li
(University of Science and Technology of China)
Prof.
Yinxian Jie
(ASIPP)
Mr
Zhiyong Zou
(University of Science and Technology of China)
