Preliminary measurements of the edge magnetic field pitch from 2-D Doppler backscattering in MAST and NSTX-U (invited)

Vann, R. G. L.; Brunner, K. J.; Ellis, R.; Taylor, G.; Thomas, D. A.

doi:10.1063/1.4962253

Title: Preliminary measurements of the edge magnetic field pitch from 2-D Doppler backscattering in MAST and NSTX-U (invited)

Abstract

The Synthetic Aperture Microwave Imaging (SAMI) system is a novel diagnostic consisting of an array of 8 independently phased antennas. At any one time, SAMI operates at one of the 16 frequencies in the range 10-34.5 GHz. The imaging beam is steered in software post-shot to create a picture of the entire emission surface. In SAMI’s active probing mode of operation, the plasma edge is illuminated with a monochromatic source and SAMI reconstructs an image of the Doppler back-scattered (DBS) signal. By assuming that density fluctuations are extended along magnetic field lines, and knowing that the strongest back-scattered signals are directed perpendicular to the density fluctuations, SAMI’s 2-D DBS imaging capability can be used to measure the pitch of the edge magnetic field. In this paper, we present preliminary pitch angle measurements obtained by SAMI on the Mega Amp Spherical Tokamak (MAST) at Culham Centre for Fusion Energy and on the National Spherical Torus Experiment Upgrade at Princeton Plasma Physics Laboratory. Lastly, the results demonstrate encouraging agreement between SAMI and other independent measurements.

Authors:

Vann, R. G. L. ^[1];

^[2]; Ellis, R. ^[3];

^[3]; Thomas, D. A. ^[4]

Univ. of York, York (United Kingdom)
Durham Univ., Durham (United Kingdom)
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Univ. of York, York (United Kingdom); Culham Science Centre, Abingdon (United Kingdom). Culhma Centre for Fusion Energy

Publication Date:: Tue Sep 13 00:00:00 EDT 2016

Research Org.:: Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

Sponsoring Org.:: USDOE

OSTI Identifier:: 1328862

Report Number(s):: 5263
Journal ID: ISSN 0034-6748; RSINAK; TRN: US1601853

Grant/Contract Number:: AC02-09CH11466

Resource Type:: Accepted Manuscript

Journal Name:: Review of Scientific Instruments

Additional Journal Information:: Journal Volume: 87; Journal Issue: 11; Journal ID: ISSN 0034-6748

Publisher:: American Institute of Physics (AIP)

Country of Publication:: United States

Language:: English

Subject:: 46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; antennas; Doppler effect; H mode; current density; plasma diagnostics

Citation Formats


                    Vann, R. G. L., Brunner, K. J., Ellis, R., Taylor, G., and Thomas, D. A. Preliminary measurements of the edge magnetic field pitch from 2-D Doppler backscattering in MAST and NSTX-U (invited).  United States: N. p., 2016. 
Web.  doi:10.1063/1.4962253.

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                    Vann, R. G. L., Brunner, K. J., Ellis, R., Taylor, G., & Thomas, D. A. Preliminary measurements of the edge magnetic field pitch from 2-D Doppler backscattering in MAST and NSTX-U (invited).  United States.  https://doi.org/10.1063/1.4962253

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                    Vann, R. G. L., Brunner, K. J., Ellis, R., Taylor, G., and Thomas, D. A. Tue .  
"Preliminary measurements of the edge magnetic field pitch from 2-D Doppler backscattering in MAST and NSTX-U (invited)".  United States.  https://doi.org/10.1063/1.4962253.  https://www.osti.gov/servlets/purl/1328862.

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@article{osti_1328862,

  title        = {Preliminary measurements of the edge magnetic field pitch from 2-D Doppler backscattering in MAST and NSTX-U (invited)},

  author       = {Vann, R. G. L. and Brunner, K. J. and Ellis, R. and Taylor, G. and Thomas, D. A.},

  abstractNote = {The Synthetic Aperture Microwave Imaging (SAMI) system is a novel diagnostic consisting of an array of 8 independently phased antennas. At any one time, SAMI operates at one of the 16 frequencies in the range 10-34.5 GHz. The imaging beam is steered in software post-shot to create a picture of the entire emission surface. In SAMI’s active probing mode of operation, the plasma edge is illuminated with a monochromatic source and SAMI reconstructs an image of the Doppler back-scattered (DBS) signal. By assuming that density fluctuations are extended along magnetic field lines, and knowing that the strongest back-scattered signals are directed perpendicular to the density fluctuations, SAMI’s 2-D DBS imaging capability can be used to measure the pitch of the edge magnetic field. In this paper, we present preliminary pitch angle measurements obtained by SAMI on the Mega Amp Spherical Tokamak (MAST) at Culham Centre for Fusion Energy and on the National Spherical Torus Experiment Upgrade at Princeton Plasma Physics Laboratory. Lastly, the results demonstrate encouraging agreement between SAMI and other independent measurements.},

  doi          = {10.1063/1.4962253},

  journal      = {Review of Scientific Instruments},

  number       = 11,

  volume       = 87,

  place        = {United States},

  year         = {Tue Sep 13 00:00:00 EDT 2016},

  month        = {Tue Sep 13 00:00:00 EDT 2016}

}

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Works referenced in this record:

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Zohm, H.
Plasma Physics and Controlled Fusion, Vol. 38, Issue 2
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A 130 point Nd:YAG Thomson scattering diagnostic on MAST
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Radial resolution enhancement of the NSTX Thomson scattering diagnostic
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Asymmetries in the motional Stark effect emission on the DIII-D tokamak
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Victor, B. S.; Holcomb, C. T.; Allen, S. L.
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A new beam emission polarimetry diagnostic for measuring the magnetic field line angle at the plasma edge of ASDEX Upgrade
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Viezzer, E.; Dux, R.; Dunne, M. G.
Review of Scientific Instruments, Vol. 87, Issue 11
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Full-wave feasibility study of anti-radar diagnostic of magnetic field based on O-X mode conversion and oblique reflectometry imaging
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Meneghini, Orso; Volpe, Francesco A.
Review of Scientific Instruments, Vol. 87, Issue 11
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Theoretical and experimental investigation of the phase-runaway in microwave reflectometry
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2D Doppler backscattering using synthetic aperture microwave imaging of MAST edge plasmas
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Synthetic aperture microwave imaging with active probing for fusion plasma diagnostics
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Shevchenko, V. F.; Vann, R. G. L.; Freethy, S. J.
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Optimization of Wide Field Interferometric Arrays via Simulated Annealing of a Beam Efficiency Function
journal, November 2012

Freethy, S. J.; Shevchenko, V. F.; Vann, R. G. L.
IEEE Transactions on Antennas and Propagation, Vol. 60, Issue 11
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FPGA-based embedded Linux technology in fusion: The MAST microwave imaging system
journal, December 2012

Huang, B. K.; Vann, R. G. L.; Freethy, S.
Fusion Engineering and Design, Vol. 87, Issue 12
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Modifications to the synthetic aperture microwave imaging diagnostic
journal, September 2016

Brunner, K. J.; Chorley, J. C.; Dipper, N. A.
Review of Scientific Instruments, Vol. 87, Issue 11
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GPU-Based Data Processing for 2-D Microwave Imaging on MAST
journal, May 2016

Chorley, J. C.; Akers, R. J.; Brunner, K. J.
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Overview of MAST results
journal, June 2015

Chapman, I. T.; Adamek, J.; Akers, R. J.
Nuclear Fusion, Vol. 55, Issue 10
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Lensless passive and active microwave imaging on MAST
journal, November 2013

Freethy, S. J.; Huang, B. K.; Shevchenko, V. F.
Plasma Physics and Controlled Fusion, Vol. 55, Issue 12
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Electron Kinetics Inferred from Observations of Microwave Bursts During Edge Localized Modes in the Mega-Amp Spherical Tokamak
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Freethy, S. J.; McClements, K. G.; Chapman, S. C.
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Works referencing / citing this record:

Scenario development during commissioning operations on the National Spherical Torus Experiment Upgrade
journal, February 2018

Battaglia, D. J.; Boyer, M. D.; Gerhardt, S.
Nuclear Fusion, Vol. 58, Issue 4
DOI: 10.1088/1741-4326/aaa6e0

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Title: Preliminary measurements of the edge magnetic field pitch from 2-D Doppler backscattering in MAST and NSTX-U (invited)

Abstract

Citation Formats

Edge localized modes (ELMs) journal, February 1996

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Asymmetries in the motional Stark effect emission on the DIII-D tokamak journal, August 2016

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Edge localized modes (ELMs)
journal, February 1996

A 130 point Nd:YAG Thomson scattering diagnostic on MAST
journal, October 2010

Radial resolution enhancement of the NSTX Thomson scattering diagnostic
journal, October 2012

Asymmetries in the motional Stark effect emission on the DIII-D tokamak
journal, August 2016

A new beam emission polarimetry diagnostic for measuring the magnetic field line angle at the plasma edge of ASDEX Upgrade
journal, August 2016

Full-wave feasibility study of anti-radar diagnostic of magnetic field based on O-X mode conversion and oblique reflectometry imaging
journal, August 2016

The Synthesis of Large Radio Telescopes
journal, March 1960

The 5-km Radio Telescope at Cambridge
journal, October 1972

Theoretical and experimental investigation of the phase-runaway in microwave reflectometry
journal, November 1998

2D Doppler backscattering using synthetic aperture microwave imaging of MAST edge plasmas
journal, January 2016

Synthetic aperture microwave imaging with active probing for fusion plasma diagnostics
journal, October 2012

Optimization of Wide Field Interferometric Arrays via Simulated Annealing of a Beam Efficiency Function
journal, November 2012

FPGA-based embedded Linux technology in fusion: The MAST microwave imaging system
journal, December 2012

Modifications to the synthetic aperture microwave imaging diagnostic
journal, September 2016

GPU-Based Data Processing for 2-D Microwave Imaging on MAST
journal, May 2016

Overview of MAST results
journal, June 2015

Lensless passive and active microwave imaging on MAST
journal, November 2013

Electron Kinetics Inferred from Observations of Microwave Bursts During Edge Localized Modes in the Mega-Amp Spherical Tokamak
journal, March 2015

Overview of the physics and engineering design of NSTX upgrade
journal, July 2012

Scenario development during commissioning operations on the National Spherical Torus Experiment Upgrade
journal, February 2018