A 16-channel electron cyclotron emission （ECE） radiometer has been employed to observe the （m, n） = （2, 1） magnetic island structure on HT-7 tokamak, where m and n represent the poloidal and toroidal mode number...A 16-channel electron cyclotron emission （ECE） radiometer has been employed to observe the （m, n） = （2, 1） magnetic island structure on HT-7 tokamak, where m and n represent the poloidal and toroidal mode number respectively. The results indicate that the island width is about 7 cm when the magnetic island is saturated during the m/n = 2/1 mode. The location of resonance surface can be determined by plotting the contour of ECE relative fluctuation. This method could be applied to the HT-7 and EAST campaigns in the future for the research of neoclassical tearing modes （NTMs）.展开更多
ECE imaging （electron cyclotron emission imaging） is an important diagnostic which can give 2D imaging of temperature fluctuation in the core of tokamak. A method based on ECE imaging is introduced which can give th...ECE imaging （electron cyclotron emission imaging） is an important diagnostic which can give 2D imaging of temperature fluctuation in the core of tokamak. A method based on ECE imaging is introduced which can give the information of the position of magnetic axis and the structure of internal magnetic surface for EAST tokamak. The EFIT equilibrium reconstruction is not reliable due to the absence of important core diagnostic at the initial phase for EAST, so the information given by ECE imaging could help to improve the accuracy of EFIT equilibrium reconstruction.展开更多
The width of a magnetic island is an important parameter for the quantitative analysis of magnetohydrodynamic-related physics. An electron cyclotron emission radiometer(ECE) is a powerful tool that can be used to obta...The width of a magnetic island is an important parameter for the quantitative analysis of magnetohydrodynamic-related physics. An electron cyclotron emission radiometer(ECE) is a powerful tool that can be used to obtain this width, which can usually be determined from the flat temperature distribution at the O-point phase or the maxima temperature perturbation. An improved method to estimate the width of a magnetic island is proposed in this paper, and it is independent of calibration. With this method and the existing 24-channel ECE system, the width of a rotation magnetic island can be estimated. Additionally, by filtering the fluctuation ECE signal, the evolution of the magnetic island can be obtained. The results of this method are consistent with those of the integrated magnetic probe signals, which represent the relative change of the magnetic island.展开更多
Accurate detection of a magnetic island in real time is one of the important issues for the tearing mode（TM） and neoclassical tearing mode（NTM） control.This paper presents a real-time detection system for the magn...Accurate detection of a magnetic island in real time is one of the important issues for the tearing mode（TM） and neoclassical tearing mode（NTM） control.This paper presents a real-time detection system for the magnetic island of NTM control in the EAST Plasma Control System（PCS）.Diagnosis is based on magnetic periodic perturbation and electron temperature fluctuation caused by the magnetic island.Therefore,a Mirnov measurement has been selected to calculate the island＇s parameters,such as island width,frequency of island rotation,and toroidal number.The electron cyclotron emission（ECE） system can detect the island position,which is calculated by two fast detection algorithms called correlation analysis and Hilbert transform.For future NTM control,real-time equilibrium reconstruction（rt-EFIT） is needed to locate the rational q-surface where the island is detected.This fast detection system is able to detect an island within 3 ms.It can be integrated into PCS to provide effective parameters of the island for NTM control by using EC resonance heating（ECRH） in the next experiment of EAST.展开更多
基金supported by the National Magnetic Confinement Fusion Science Program of China (Nos.2010GB106000 and 2010GB106001)
文摘A 16-channel electron cyclotron emission （ECE） radiometer has been employed to observe the （m, n） = （2, 1） magnetic island structure on HT-7 tokamak, where m and n represent the poloidal and toroidal mode number respectively. The results indicate that the island width is about 7 cm when the magnetic island is saturated during the m/n = 2/1 mode. The location of resonance surface can be determined by plotting the contour of ECE relative fluctuation. This method could be applied to the HT-7 and EAST campaigns in the future for the research of neoclassical tearing modes （NTMs）.
基金supported by National Natural Science Foundation of China(Nos.11205197,10335060)the National Basic Research Program of China(No.2008CB717800)+3 种基金Grants from the Ministry of Education and the Chinese Academy of Sciencesthe CAS-JSPS Core University Program in Plasma and Nuclear Fusionthe PRC-US Fusion Cooperation Program(Plasma Physics,Project A-5)the Office of Fusion Energy Science,U.S.Department of Energy
文摘ECE imaging （electron cyclotron emission imaging） is an important diagnostic which can give 2D imaging of temperature fluctuation in the core of tokamak. A method based on ECE imaging is introduced which can give the information of the position of magnetic axis and the structure of internal magnetic surface for EAST tokamak. The EFIT equilibrium reconstruction is not reliable due to the absence of important core diagnostic at the initial phase for EAST, so the information given by ECE imaging could help to improve the accuracy of EFIT equilibrium reconstruction.
基金supported by the National Magnetic Confinement Fusion Program of China (Nos. 2015GB120003 and 2014GB108001)
文摘The width of a magnetic island is an important parameter for the quantitative analysis of magnetohydrodynamic-related physics. An electron cyclotron emission radiometer(ECE) is a powerful tool that can be used to obtain this width, which can usually be determined from the flat temperature distribution at the O-point phase or the maxima temperature perturbation. An improved method to estimate the width of a magnetic island is proposed in this paper, and it is independent of calibration. With this method and the existing 24-channel ECE system, the width of a rotation magnetic island can be estimated. Additionally, by filtering the fluctuation ECE signal, the evolution of the magnetic island can be obtained. The results of this method are consistent with those of the integrated magnetic probe signals, which represent the relative change of the magnetic island.
基金supported by the National Magnetic Confinement Fusion Science Program of China(Nos.2014GB103000,2012GB103000,and2012GB103002)National Natural Science Foundation of China(No.11205200)
文摘Accurate detection of a magnetic island in real time is one of the important issues for the tearing mode（TM） and neoclassical tearing mode（NTM） control.This paper presents a real-time detection system for the magnetic island of NTM control in the EAST Plasma Control System（PCS）.Diagnosis is based on magnetic periodic perturbation and electron temperature fluctuation caused by the magnetic island.Therefore,a Mirnov measurement has been selected to calculate the island＇s parameters,such as island width,frequency of island rotation,and toroidal number.The electron cyclotron emission（ECE） system can detect the island position,which is calculated by two fast detection algorithms called correlation analysis and Hilbert transform.For future NTM control,real-time equilibrium reconstruction（rt-EFIT） is needed to locate the rational q-surface where the island is detected.This fast detection system is able to detect an island within 3 ms.It can be integrated into PCS to provide effective parameters of the island for NTM control by using EC resonance heating（ECRH） in the next experiment of EAST.
