Far-infrared(FIR)interferometer is widely used to measure the electron density in the magnetically confined fusion plasma devices.A new FIR laser interferometer with a total of 13 channels(8 horizontal channels and 5 ...Far-infrared(FIR)interferometer is widely used to measure the electron density in the magnetically confined fusion plasma devices.A new FIR laser interferometer with a total of 13 channels(8 horizontal channels and 5 oblique channels)is under development on the HL-3tokamak by using the formic-acid laser(HCOOH,f=694 GHz).In order to investigate the boundary electron density activity during the divertor discharge,three horizontal interferometry channels located at Z=-97,-76,76.5 cm have been successfully developed on HL-3 in 2023,and put into operation in recent experimental campaign,with a time resolution of<1.0μs and lineintegrated electron density resolution of~7.0×10^(16) m^(-2).This paper mainly focuses on the optical design of the three-channel interferometry system,as well as optical elements and recent experimental result on HL-3.展开更多
A synchronous demodulation system is proposed and deployed for CO_2 dispersion interferometer on HL-2 A,which aims at high plasma density measurements and real-time feedback control.In order to make sure that the demo...A synchronous demodulation system is proposed and deployed for CO_2 dispersion interferometer on HL-2 A,which aims at high plasma density measurements and real-time feedback control.In order to make sure that the demodulator and the interferometer signal are synchronous in phase,a phase adjustment（PA） method has been developed for the demodulation system.The method takes advantages of the field programmable gate array parallel and pipeline process capabilities to carry out high performance and low latency PA.Some experimental results presented show that the PA method is crucial to the synchronous demodulation system and reliable to follow the fast change of the electron density.The system can measure the lineintegrated density with a high precision of 2.0？×10^（18）m^（-2）.展开更多
基金supported by the National Magnetic Confinement Fusion Science Program of China(Nos.2019YFE03020004,2018YFE0304102 and 2019YFE03020002)the Department of Science and Technology of Sichuan Province(No.2020YJ0463)。
文摘Far-infrared(FIR)interferometer is widely used to measure the electron density in the magnetically confined fusion plasma devices.A new FIR laser interferometer with a total of 13 channels(8 horizontal channels and 5 oblique channels)is under development on the HL-3tokamak by using the formic-acid laser(HCOOH,f=694 GHz).In order to investigate the boundary electron density activity during the divertor discharge,three horizontal interferometry channels located at Z=-97,-76,76.5 cm have been successfully developed on HL-3 in 2023,and put into operation in recent experimental campaign,with a time resolution of<1.0μs and lineintegrated electron density resolution of~7.0×10^(16) m^(-2).This paper mainly focuses on the optical design of the three-channel interferometry system,as well as optical elements and recent experimental result on HL-3.
基金supported by the National Magnetic Confinement Fusion Science Program of China (Nos.2014GB109001 and 2013GB104003)National Natural Science Foundation of China (Grant Nos.11375195,11505053,and 11575184)
文摘A synchronous demodulation system is proposed and deployed for CO_2 dispersion interferometer on HL-2 A,which aims at high plasma density measurements and real-time feedback control.In order to make sure that the demodulator and the interferometer signal are synchronous in phase,a phase adjustment（PA） method has been developed for the demodulation system.The method takes advantages of the field programmable gate array parallel and pipeline process capabilities to carry out high performance and low latency PA.Some experimental results presented show that the PA method is crucial to the synchronous demodulation system and reliable to follow the fast change of the electron density.The system can measure the lineintegrated density with a high precision of 2.0？×10^（18）m^（-2）.
