Measurement of Turbulence Propagation Velocity Using Doppler Reflectometer on HL-2A Tokamak

Wei-wen, Xiao; Ding, X.T.; Liu, Zetian; Lianghua, Yao; Sun, Hong‐Bo; Duan, X.R.; Longwen, Yan; Qi, Yang

doi:10.1088/1009-0630/10/4/01

Cited by 27 publications

(7 citation statements)

References 13 publications

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“…No Doppler peak is visible in the spectra as obtained on single horn DBS experiments [2,4,5,6,7,8,9,22,10] due to imperfect sideband suppression.…”

Section: Data Analysis Techniquesmentioning

confidence: 90%

“…DBS experiments have been used to measure the perpendicular velocity profiles of turbulence structurures and turbulence amplitude on ASDEX Upgrade (AUG) [2], DIII-D [3], W7-AS [4,5], EAST [6], HL-2A [7], LHD [8], L-2M [9] and MAST [10]. Turbulence velocity profiles are of interest as radial velocity shear has been shown to influence the stability properties of drift-type instabilities, for example [11].…”

Section: Introductionmentioning

confidence: 99%

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Observations of 2D Doppler backscattering on MAST

Thomas,

Brunner,

Freethy

et al. 2015

Preprint

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The Synthetic Aperture Microwave Imaging (SAMI) diagnostic has conducted proof-of-principle 2D Doppler backscattering (DBS) experiments on MAST. SAMI actively probes the plasma edge using a wide (±40°vertical and horizontal) and tuneable (10-35.5 GHz) beam. The Doppler backscattered signal is digitised in vector form using an array of eight Vivaldi PCB antennas. This allows the receiving array to be focused in any direction within the field of view simultaneously to an angular range of 6-24°FWHM at 10-34.5 GHz. This capability is unique to SAMI and is an entirely novel way of conducting DBS experiments. In this paper the feasibility of conducting 2D DBS experiments is explored. Initial measurements of phenomena observed on conventional DBS experiments are presented; such as momentum injection from neutral beams and an abrupt change in power and turbulence velocity coinciding with the onset of Hmode. In addition, being able to carry out 2D DBS imaging allows a measurement of magnetic pitch angle to be made; preliminary results are presented. Capabilities gained through steering a beam using a phased array and the limitations of this technique are discussed.

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“…No Doppler peak is visible in the spectra as obtained on single horn DBS experiments [2,4,5,6,7,8,9,22,10] due to imperfect sideband suppression.…”

Section: Data Analysis Techniquesmentioning

confidence: 90%

Section: Introductionmentioning

confidence: 99%

Observations of 2D Doppler backscattering on MAST

Thomas,

Brunner,

Freethy

et al. 2015

Preprint

View full text Add to dashboard Cite

show abstract

“…Three frequency modulation continuous wave (FMCW) reflectometers and two amplitude modulation (AM) reflectometers are developed to measure the density profiles from low field side in the horizontal plane [31][32][33][34]. Two sweeping DBS reflectometers and four by four fixed-frequency DBS reflectometers are developed to measure the profiles of the plasma rotation and turbulence [15,35,36].…”

Section: Overview Of Microwave Diagnostics On Hl-2amentioning

confidence: 99%

“…The basic requirements of the DBS measurement are the quadrature phase measurement and the tilt antenna system with respect to the normal cut-off surface. For the purpose of principle verification, two homodyne O-mode fixed-frequency reflectometers were used for DBS measurement in 2008 [35]. The changes of the power spectra caused by turbulence rotation have been observed with Ohmic and ECRH heating.…”

Section: Doppler Backward Scattering Reflectometermentioning

confidence: 99%

Progress of microwave diagnostics development on the HL-2A tokamak

Shi

Zhong

Jiang

2018

Plasma Sci. Technol.

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Sets of powerful microwave diagnostic systems have been developed on the HL-2A tokamak, including 18 subsystems with high spatial and temporal resolutions. These systems have been applied in the HL-2A tokamak experiments to investigate the core plasma transport, turbulence, MHD, energetic particle physics and so on. In this paper, the microwave diagnostics and their applications are reviewed. Some new technologies, including GHz sampling digital correlation electron cyclotron emission (DCECE), multi-channel correlation reflectometers, and solid state terahertz interferometers, are also presented in the paper.

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“…DBS experiments have been used to measure the perpendicular velocity profiles of turbulence structurures and turbulence amplitude at ASDEX Upgrade (AUG) [2], DIII-D [3], W7-AS [4,5], EAST [6], HL-2A [7], LHD [8], L-2M [9] and MAST [10]. Turbulence velocity profiles are of interest as radial velocity shear has been shown to influence the stability properties of drift-type instabilities, for example [11].…”

Section: Introductionmentioning

confidence: 99%

2D Doppler backscattering using synthetic aperture microwave imaging of MAST edge plasmas

et al. 2016

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Doppler backscattering (DBS) is already established as a powerful diagnostic; its extension to 2D enables imaging of turbulence characteristics from an extended region of the cut-off surface. The Synthetic Aperture Microwave Imaging (SAMI) diagnostic has conducted proof-of-principle 2D DBS experiments of MAST edge plasma. SAMI actively probes the plasma edge using a wide (±40° vertical and horizontal) and tuneable (10–34.5 GHz) beam. The Doppler backscattered signal is digitised in vector form using an array of eight Vivaldi PCB antennas. This allows the receiving array to be focused in any direction within the field of view simultaneously to an angular range of 6–24° FWHM at 10–34.5 GHz. This capability is unique to SAMI and is a novel way of conducting DBS experiments. In this paper the feasibility of conducting 2D DBS experiments is explored. Initial observations of phenomena previously measured by conventional DBS experiments are presented; such as momentum injection from neutral beams and an abrupt change in power and turbulence velocity coinciding with the onset of H-mode. In addition, being able to carry out 2D DBS imaging allows a measurement of magnetic pitch angle to be made; preliminary results are presented. Capabilities gained through steering a beam using a phased array and the limitations of this technique are discussed.

show abstract

Measurement of Turbulence Propagation Velocity Using Doppler Reflectometer on HL-2A Tokamak

Cited by 27 publications

References 13 publications

Observations of 2D Doppler backscattering on MAST

Observations of 2D Doppler backscattering on MAST

Progress of microwave diagnostics development on the HL-2A tokamak

2D Doppler backscattering using synthetic aperture microwave imaging of MAST edge plasmas

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