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Improved accuracy a...
Improved accuracy and robustness of electron density profiles from JET’s X-mode frequency-modulated continuous-wave reflectometers
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- Morales, R. B. (author)
- UKAEA (United Kingdom Atomic Energy Authority), Culham Campus, Abingdon, Oxfordshire OX14 3DB, United Kingdom, Abingdon
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- Salmi, A. (author)
- VTT, P.O. Box 1000, FI-02044 VTT Espoo, Finland, P.O. Box 1000, VTT Espoo
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- Abreu, P. (author)
- IPFN, Instituto Superior Técnico da Universidade de Lisboa, 1049-001 Lisboa, Portugal
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- Amador, C. H.S. (author)
- Federal University of Technology—Parana (UTFPR), Department of Natural Sciences, Cornélio Procópio, Brazil
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- Appel, L. (author)
- UKAEA (United Kingdom Atomic Energy Authority), Culham Campus, Abingdon, Oxfordshire OX14 3DB, United Kingdom, Abingdon
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- Carman, P. (author)
- UKAEA (United Kingdom Atomic Energy Authority), Culham Campus, Abingdon, Oxfordshire OX14 3DB, United Kingdom, Abingdon
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- Fessey, J. (author)
- UKAEA (United Kingdom Atomic Energy Authority), Culham Campus, Abingdon, Oxfordshire OX14 3DB, United Kingdom, Abingdon
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- Flanagan, J. (author)
- UKAEA (United Kingdom Atomic Energy Authority), Culham Campus, Abingdon, Oxfordshire OX14 3DB, United Kingdom, Abingdon
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- Fontana, M. (author)
- UKAEA (United Kingdom Atomic Energy Authority), Culham Campus, Abingdon, Oxfordshire OX14 3DB, United Kingdom, Abingdon
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- Frassinetti, Lorenzo (author)
- KTH,Elektromagnetism och fusionsfysik
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- Giroud, C. (author)
- UKAEA (United Kingdom Atomic Energy Authority), Culham Campus, Abingdon, Oxfordshire OX14 3DB, United Kingdom, Abingdon
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- Hacquin, S. (author)
- IRFM, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
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- Heuraux, S. (author)
- IJL, University of Lorraine, UMR 7198 CNRS, BP 50840, 54011 Nancy Cedex, France, BP 50840
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- Meneses, L. (author)
- ITER Organization, Route de Vinon, CS 90 046, 13067 Saint-Paul-Lez-Durance, France, Route de Vinon, CS 90 046
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- Ronchi, G. (author)
- Oak Ridge National Laboratory, Oak Ridge, Tennessee, Tennessee 37830, USA
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- Sabot, R. (author)
- IRFM, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
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- Silva, A. (author)
- IPFN, Instituto Superior Técnico da Universidade de Lisboa, 1049-001 Lisboa, Portugal
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- Sirinelli, A. (author)
- ITER Organization, Route de Vinon, CS 90 046, 13067 Saint-Paul-Lez-Durance, France, Route de Vinon, CS 90 046
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- Szepesi, G. (author)
- UKAEA (United Kingdom Atomic Energy Authority), Culham Campus, Abingdon, Oxfordshire OX14 3DB, United Kingdom, Abingdon
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- Taylor, D. (author)
- UKAEA (United Kingdom Atomic Energy Authority), Culham Campus, Abingdon, Oxfordshire OX14 3DB, United Kingdom, Abingdon
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- Terranova, D. (author)
- Consorzio RFX and ISTP-CNR, Corso Stati Uniti 4, 35127 Padova, Italy, Corso Stati Uniti 4
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UKAEA (United Kingdom Atomic Energy Authority), Culham Campus, Abingdon, Oxfordshire OX14 3DB, United Kingdom, Abingdon VTT, PO. Box 1000, FI-02044 VTT Espoo, Finland, P.O. Box 1000, VTT Espoo (creator_code:org_t)
- AIP Publishing, 2024
- 2024
- English.
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In: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 95:4
- Related links:
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https://doi.org/10.1...
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https://urn.kb.se/re...
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Abstract
Subject headings
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- JET’s frequency-modulated continuous wave (FMCW) reflectometers have been operating well with the current design since 2005, and density profiles have been automatically calculated intershot since then. However, the calculated profiles had long suffered from several shortcomings: poor agreement with other diagnostics, sometimes inappropriately moving radially by several centimeters, elevated levels of radial jitter, and persistent wriggles (strong unphysical oscillations). In this research, several techniques are applied to the reflectometry data analysis, and the shortcomings are significantly improved. Starting with improving the equilibrium reconstruction that estimates the background magnetic field, adding a ripple correction in the reconstructed magnetic field profile, and adding new inner-wall reflection positions estimated through ray-tracing, these changes not only improve the agreement of reconstructed profiles to other diagnostics but also solve density profile wriggles that were present during band transitions. Other smaller but also persistent wriggles were also suppressed by applying a localized correction to the measured beat frequency where persistent oscillations are present. Finally, the burst analysis method, as introduced by Varela et al. [Nucl. Fusion 46 S693 (2006)], has been implemented to extract the beat frequency from stacked spectrograms. Due to the strong suppression of spurious reflections, the radial jitter that sometimes would span several centimeters has been strongly reduced. The stacking of spectrograms has also been shown to be very useful for stacking recurring events, like small gas puff modulations, and extracting transport coefficients that would otherwise be below the noise level.
Subject headings
- NATURVETENSKAP -- Fysik (hsv//swe)
- NATURAL SCIENCES -- Physical Sciences (hsv//eng)
Publication and Content Type
- ref (subject category)
- art (subject category)
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- By the author/editor
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Morales, R. B.
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Salmi, A.
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Abreu, P.
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Amador, C. H.S.
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Appel, L.
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Carman, P.
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show more...
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Fessey, J.
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Flanagan, J.
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Fontana, M.
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Frassinetti, Lor ...
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Giroud, C.
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Hacquin, S.
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Heuraux, S.
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Meneses, L.
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Ronchi, G.
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Sabot, R.
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Silva, A.
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Sirinelli, A.
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Szepesi, G.
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Taylor, D.
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Terranova, D.
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- About the subject
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- NATURAL SCIENCES
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NATURAL SCIENCES
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and Physical Science ...
- Articles in the publication
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Review of Scient ...
- By the university
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Royal Institute of Technology