Improved weighted sum estimation of total radiated power at W7-X

As magnetic confinement devices move toward higher fusion powers, moderating the heat load to the plasma-facing components becomes increasingly challenging. Efficient power dissipation can be achieved through control of the plasma radiation. However, defining a reliable proxy for the total radiated...

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Main Authors: G. Partesotti, F. Reimold, A. Tsikouras, D. Zhang, G. Kawamura, B.J. Peterson, the W7-X Team
Format: Article
Language:English
Published: IOP Publishing 2024-01-01
Series:Nuclear Fusion
Subjects:
Online Access:https://doi.org/10.1088/1741-4326/ad9488
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author G. Partesotti
F. Reimold
A. Tsikouras
D. Zhang
G. Kawamura
B.J. Peterson
the W7-X Team
author_facet G. Partesotti
F. Reimold
A. Tsikouras
D. Zhang
G. Kawamura
B.J. Peterson
the W7-X Team
author_sort G. Partesotti
collection DOAJ
description As magnetic confinement devices move toward higher fusion powers, moderating the heat load to the plasma-facing components becomes increasingly challenging. Efficient power dissipation can be achieved through control of the plasma radiation. However, defining a reliable proxy for the total radiated power is particularly challenging for non-axisymmetric devices such as stellarators. To address this problem, the radiated power can be estimated through a sum of the individual line-integrated bolometer measurements with weights properly calculated to account for the three-dimensional magnetic geometry. The present contribution aims to apply this weighted sum approach to Wendelstein 7-X (W7-X) and quantitatively validate it. First, we generate synthetic radiated power phantoms with characteristic W7-X radiation features to derive a set of optimized line-of-sight weights. Then, we test the weights on mock-ups and EMC3-EIRENE radiation patterns, including acquisition and analysis errors such as random noise fluctuations, camera misalignments, and field errors. Compared to other methods, the optimized weighted sum technique exhibited the best performance in all the presented synthetic test cases. When applied to experimental bolometer data, the optimized weights provided a proxy that is both reliable and real-time capable. Further validation is foreseen for the next experimental campaign.
format Article
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institution Kabale University
issn 0029-5515
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publishDate 2024-01-01
publisher IOP Publishing
record_format Article
series Nuclear Fusion
spelling doaj-art-8532892ee88e4c20af9fd9eb41717eea2024-11-29T15:33:48ZengIOP PublishingNuclear Fusion0029-55152024-01-0165101603510.1088/1741-4326/ad9488Improved weighted sum estimation of total radiated power at W7-XG. Partesotti0https://orcid.org/0009-0008-9465-7885F. Reimold1https://orcid.org/0000-0003-4251-7924A. Tsikouras2https://orcid.org/0009-0008-9677-3302D. Zhang3https://orcid.org/0000-0002-5800-4907G. Kawamura4https://orcid.org/0000-0002-9117-5898B.J. Peterson5https://orcid.org/0009-0002-8230-0121the W7-X TeamMax-Planck-Institut für Plasmaphysik , Greifswald, GermanyMax-Planck-Institut für Plasmaphysik , Greifswald, GermanyMax-Planck-Institut für Plasmaphysik , Greifswald, GermanyMax-Planck-Institut für Plasmaphysik , Greifswald, GermanyNational Institute for Fusion Science , Toki, Japan; National Institutes for Quantum Science and Technology , Rokkasho, JapanNational Institute for Fusion Science , Toki, JapanAs magnetic confinement devices move toward higher fusion powers, moderating the heat load to the plasma-facing components becomes increasingly challenging. Efficient power dissipation can be achieved through control of the plasma radiation. However, defining a reliable proxy for the total radiated power is particularly challenging for non-axisymmetric devices such as stellarators. To address this problem, the radiated power can be estimated through a sum of the individual line-integrated bolometer measurements with weights properly calculated to account for the three-dimensional magnetic geometry. The present contribution aims to apply this weighted sum approach to Wendelstein 7-X (W7-X) and quantitatively validate it. First, we generate synthetic radiated power phantoms with characteristic W7-X radiation features to derive a set of optimized line-of-sight weights. Then, we test the weights on mock-ups and EMC3-EIRENE radiation patterns, including acquisition and analysis errors such as random noise fluctuations, camera misalignments, and field errors. Compared to other methods, the optimized weighted sum technique exhibited the best performance in all the presented synthetic test cases. When applied to experimental bolometer data, the optimized weights provided a proxy that is both reliable and real-time capable. Further validation is foreseen for the next experimental campaign.https://doi.org/10.1088/1741-4326/ad9488plasmaradiationbolometerpowerstellarator
spellingShingle G. Partesotti
F. Reimold
A. Tsikouras
D. Zhang
G. Kawamura
B.J. Peterson
the W7-X Team
Improved weighted sum estimation of total radiated power at W7-X
Nuclear Fusion
plasma
radiation
bolometer
power
stellarator
title Improved weighted sum estimation of total radiated power at W7-X
title_full Improved weighted sum estimation of total radiated power at W7-X
title_fullStr Improved weighted sum estimation of total radiated power at W7-X
title_full_unstemmed Improved weighted sum estimation of total radiated power at W7-X
title_short Improved weighted sum estimation of total radiated power at W7-X
title_sort improved weighted sum estimation of total radiated power at w7 x
topic plasma
radiation
bolometer
power
stellarator
url https://doi.org/10.1088/1741-4326/ad9488
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AT dzhang improvedweightedsumestimationoftotalradiatedpoweratw7x
AT gkawamura improvedweightedsumestimationoftotalradiatedpoweratw7x
AT bjpeterson improvedweightedsumestimationoftotalradiatedpoweratw7x
AT thew7xteam improvedweightedsumestimationoftotalradiatedpoweratw7x