2D Doppler backscattering using synthetic aperture microwave imaging of MAST edge plasmas
Abstract 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...
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Online Access: | http://dx.doi.org/10.1088/0029-5515/56/2/026013 http://stacks.iop.org/0029-5515/56/i=2/a=026013/pdf http://stacks.iop.org/0029-5515/56/i=2/a=026013?key=crossref.bf20f9fa0cbba8ecdaf8d1f7ebcd8caf https://iopscience.iop.org/article/10.1088/0029-5515/56/2/026013 https://iopscience.iop.org/article/10.1088/0029-5515/56/2/026013/pdf |
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crioppubl:10.1088/0029-5515/56/2/026013 2024-06-02T08:14:03+00:00 2D Doppler backscattering using synthetic aperture microwave imaging of MAST edge plasmas Thomas, D.A. Brunner, K.J. Freethy, S.J. Huang, B.K. Shevchenko, V.F. Vann, R.G.L. Euratom research and training programme Engineering and Physical Sciences Research Council Research Councils UK 2016 http://dx.doi.org/10.1088/0029-5515/56/2/026013 http://stacks.iop.org/0029-5515/56/i=2/a=026013/pdf http://stacks.iop.org/0029-5515/56/i=2/a=026013?key=crossref.bf20f9fa0cbba8ecdaf8d1f7ebcd8caf https://iopscience.iop.org/article/10.1088/0029-5515/56/2/026013 https://iopscience.iop.org/article/10.1088/0029-5515/56/2/026013/pdf unknown IOP Publishing http://creativecommons.org/licenses/by/3.0/ https://iopscience.iop.org/info/page/text-and-data-mining Nuclear Fusion volume 56, issue 2, page 026013 ISSN 0029-5515 1741-4326 journal-article 2016 crioppubl https://doi.org/10.1088/0029-5515/56/2/026013 2024-05-07T14:02:09Z Abstract 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. Article in Journal/Newspaper sami IOP Publishing Nuclear Fusion 56 2 026013 |
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IOP Publishing |
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unknown |
description |
Abstract 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. |
author2 |
Euratom research and training programme Engineering and Physical Sciences Research Council Research Councils UK |
format |
Article in Journal/Newspaper |
author |
Thomas, D.A. Brunner, K.J. Freethy, S.J. Huang, B.K. Shevchenko, V.F. Vann, R.G.L. |
spellingShingle |
Thomas, D.A. Brunner, K.J. Freethy, S.J. Huang, B.K. Shevchenko, V.F. Vann, R.G.L. 2D Doppler backscattering using synthetic aperture microwave imaging of MAST edge plasmas |
author_facet |
Thomas, D.A. Brunner, K.J. Freethy, S.J. Huang, B.K. Shevchenko, V.F. Vann, R.G.L. |
author_sort |
Thomas, D.A. |
title |
2D Doppler backscattering using synthetic aperture microwave imaging of MAST edge plasmas |
title_short |
2D Doppler backscattering using synthetic aperture microwave imaging of MAST edge plasmas |
title_full |
2D Doppler backscattering using synthetic aperture microwave imaging of MAST edge plasmas |
title_fullStr |
2D Doppler backscattering using synthetic aperture microwave imaging of MAST edge plasmas |
title_full_unstemmed |
2D Doppler backscattering using synthetic aperture microwave imaging of MAST edge plasmas |
title_sort |
2d doppler backscattering using synthetic aperture microwave imaging of mast edge plasmas |
publisher |
IOP Publishing |
publishDate |
2016 |
url |
http://dx.doi.org/10.1088/0029-5515/56/2/026013 http://stacks.iop.org/0029-5515/56/i=2/a=026013/pdf http://stacks.iop.org/0029-5515/56/i=2/a=026013?key=crossref.bf20f9fa0cbba8ecdaf8d1f7ebcd8caf https://iopscience.iop.org/article/10.1088/0029-5515/56/2/026013 https://iopscience.iop.org/article/10.1088/0029-5515/56/2/026013/pdf |
genre |
sami |
genre_facet |
sami |
op_source |
Nuclear Fusion volume 56, issue 2, page 026013 ISSN 0029-5515 1741-4326 |
op_rights |
http://creativecommons.org/licenses/by/3.0/ https://iopscience.iop.org/info/page/text-and-data-mining |
op_doi |
https://doi.org/10.1088/0029-5515/56/2/026013 |
container_title |
Nuclear Fusion |
container_volume |
56 |
container_issue |
2 |
container_start_page |
026013 |
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1800737747503153152 |