Real-time signal processing system based on FPGA for motional Stark effect diagnostic on EAST

doi:10.1063/5.0040814

	Real-time signal processing system based on FPGA for motional Stark effect diagnostic on EAST
	Liu, D. M.1; Yang, X. H.1; Fu, J.2; Liu, L. C.1; Lyu, B.2
刊名	REVIEW OF SCIENTIFIC INSTRUMENTS
	2021-05-01
卷号	92
ISSN号	0034-6748
DOI	10.1063/5.0040814
通讯作者	Liu, L. C.(liu-liangcheng@hfut.edu.cn)
英文摘要	The plasma current density profile plays a key role in the development of a high poloidal beta scenario, which is essential for long-pulse and high-performance plasma operation on a tokamak. Based on the polarimetry technique, a Motional Stark Effect (MSE) diagnostic has been built on the Experimental Advanced Superconducting Tokamak. To be prepared for real-time (RT) feedback control of the plasma current density profile in the future, a RT signal processing system has been developed. The RT signal processing system is composed of three functional modules: analog-to-digital conversion (ADC) module, polarization information extraction module, and digital-to-analog conversion (DAC) module. The final objective of this system is to acquire the polarization information of the MSE. Based on the field-programmable gate array unit, fast Fourier transformation is adopted to process the Photoelastic Modulator (PEM) digital signal, which was converted from a PEM signal via the ADC module. By means of frequency spectrum separation, the components around double modulating frequencies are restored through inverse fast Fourier transformation. Furthermore, the two amplitudes of their corresponding components can be obtained through a digital harmonic analyzer technique. Afterward, the ratio of the two amplitudes is calculated by arc tangent so that the polarization angle is obtained. Finally, the information of this polarization angle is converted into a voltage signal by the DAC module and then output in RT. The test results based on the RT signal processing system are in good agreement with those based on the phase lock-in amplifiers. The working cycle of this system is shorter than 10 ms, which meets the requirements of the MSE diagnostic as a RT controller. The algorithm of RT signal processing and the relevant technology applied for building this system are presented in the main body of this paper in detail. Published under license by AIP Publishing.
资助项目	National Key Research and Development Project of China[2017YFE0301105] ; National Natural Science Foundation of China[12075280] ; National Natural Science Foundation of China[11975276] ; Anhui Provincial Natural Science Foundation of China[2008085J04]
WOS研究方向	Instruments & Instrumentation ; Physics
语种	英语
出版者	AIP Publishing
WOS记录号	WOS:000692113800001
资助机构	National Key Research and Development Project of China ; National Natural Science Foundation of China ; Anhui Provincial Natural Science Foundation of China
内容类型	期刊论文
源URL	[http://ir.hfcas.ac.cn:8080/handle/334002/125225]
专题	中国科学院合肥物质科学研究院
通讯作者	Liu, L. C.
作者单位	1.Hefei Univ Technol, Sch Elect Engn & Automat, Hefei 230009, Anhui, Peoples R China 2.Chinese Acad Sci, Inst Plasma Phys, Hefei 230031, Anhui, Peoples R China
推荐引用方式 GB/T 7714	Liu, D. M.,Yang, X. H.,Fu, J.,et al. Real-time signal processing system based on FPGA for motional Stark effect diagnostic on EAST[J]. REVIEW OF SCIENTIFIC INSTRUMENTS,2021,92.
APA	Liu, D. M.,Yang, X. H.,Fu, J.,Liu, L. C.,&Lyu, B..(2021).Real-time signal processing system based on FPGA for motional Stark effect diagnostic on EAST.REVIEW OF SCIENTIFIC INSTRUMENTS,92.
MLA	Liu, D. M.,et al."Real-time signal processing system based on FPGA for motional Stark effect diagnostic on EAST".REVIEW OF SCIENTIFIC INSTRUMENTS 92(2021).