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An assessment of nitrogen concentrations from spectroscopic measurements in the JET and ASDEX upgrade divertor

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An assessment of nitrogen concentrations from spectroscopic measurements in the JET and ASDEX upgrade divertor. / The EUROfusion MST1 Team ; ASDEX Upgrade Team; JET contributors.

In: Nuclear Materials and Energy, Vol. 18, 01.01.2019, p. 147-152.

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Harvard

The EUROfusion MST1 Team , ASDEX Upgrade Team & JET contributors 2019, 'An assessment of nitrogen concentrations from spectroscopic measurements in the JET and ASDEX upgrade divertor', Nuclear Materials and Energy, vol. 18, pp. 147-152. https://doi.org/10.1016/j.nme.2018.12.012

APA

The EUROfusion MST1 Team , ASDEX Upgrade Team, & JET contributors (2019). An assessment of nitrogen concentrations from spectroscopic measurements in the JET and ASDEX upgrade divertor. Nuclear Materials and Energy, 18, 147-152. https://doi.org/10.1016/j.nme.2018.12.012

Vancouver

The EUROfusion MST1 Team , ASDEX Upgrade Team, JET contributors. An assessment of nitrogen concentrations from spectroscopic measurements in the JET and ASDEX upgrade divertor. Nuclear Materials and Energy. 2019 Jan 1;18:147-152. https://doi.org/10.1016/j.nme.2018.12.012

Author

The EUROfusion MST1 Team ; ASDEX Upgrade Team ; JET contributors. / An assessment of nitrogen concentrations from spectroscopic measurements in the JET and ASDEX upgrade divertor. In: Nuclear Materials and Energy. 2019 ; Vol. 18. pp. 147-152.

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@article{058d14e803d049d7a0ae6ca14471da6b,
title = "An assessment of nitrogen concentrations from spectroscopic measurements in the JET and ASDEX upgrade divertor",
abstract = "The impurity concentration in the tokamak divertor plasma is a necessary input for predictive scaling of divertor detachment, however direct measurements from existing tokamaks in different divertor plasma conditions are limited. To address this, we have applied a recently developed spectroscopic N II line ratio technique for measuring the N concentration in the divertor to a range of H-mode and L-mode plasma from the ASDEX Upgrade and JET tokamaks, respectively. The results from both devices show that as the power crossing the separatrix, Psep, is increased under otherwise similar core conditions (e.g. density), a higher N concentration is required to achieve the same detachment state. For example, the N concentrations at the start of detachment increase from ≈ 2{\%} to ≈ 9{\%} as Psep is increased from ≈ 2.5 MW to ≈ 7 MW. These results tentatively agree with scaling law predictions (e.g. Goldston et al.) motivating a further study examining the parameters which affect the N concentration required to reach detachment. Finally, the N concentrations from spectroscopy and the ratio of D and N gas valve fluxes agree within experimental uncertainty only when the vessel surfaces are fully-loaded with N.",
keywords = "Concentration, Divertor, Impurity, Nitrogen, Spectroscopy, Tokamak",
author = "{The EUROfusion MST1 Team} and {ASDEX Upgrade Team} and {JET contributors} and Henderson, {S. S.} and M. Bernert and S. Brezinsek and M. Carr and M. Cavedon and R. Dux and Gahle, {D. S.} and J. Harrison and A. Kallenbach and B. Lipschultz and B. Lomanowski and A. Meigs and M. O'Mullane and F. Reimold and Reinke, {M. L.} and S. Wiesen",
note = "{\circledC} 2018 Published by Elsevier Ltd.",
year = "2019",
month = "1",
day = "1",
doi = "10.1016/j.nme.2018.12.012",
language = "English",
volume = "18",
pages = "147--152",
journal = "Nuclear Materials and Energy",
issn = "2352-1791",
publisher = "Elsevier",

}

RIS (suitable for import to EndNote) - Download

TY - JOUR

T1 - An assessment of nitrogen concentrations from spectroscopic measurements in the JET and ASDEX upgrade divertor

AU - The EUROfusion MST1 Team

AU - ASDEX Upgrade Team

AU - JET contributors

AU - Henderson, S. S.

AU - Bernert, M.

AU - Brezinsek, S.

AU - Carr, M.

AU - Cavedon, M.

AU - Dux, R.

AU - Gahle, D. S.

AU - Harrison, J.

AU - Kallenbach, A.

AU - Lipschultz, B.

AU - Lomanowski, B.

AU - Meigs, A.

AU - O'Mullane, M.

AU - Reimold, F.

AU - Reinke, M. L.

AU - Wiesen, S.

N1 - © 2018 Published by Elsevier Ltd.

PY - 2019/1/1

Y1 - 2019/1/1

N2 - The impurity concentration in the tokamak divertor plasma is a necessary input for predictive scaling of divertor detachment, however direct measurements from existing tokamaks in different divertor plasma conditions are limited. To address this, we have applied a recently developed spectroscopic N II line ratio technique for measuring the N concentration in the divertor to a range of H-mode and L-mode plasma from the ASDEX Upgrade and JET tokamaks, respectively. The results from both devices show that as the power crossing the separatrix, Psep, is increased under otherwise similar core conditions (e.g. density), a higher N concentration is required to achieve the same detachment state. For example, the N concentrations at the start of detachment increase from ≈ 2% to ≈ 9% as Psep is increased from ≈ 2.5 MW to ≈ 7 MW. These results tentatively agree with scaling law predictions (e.g. Goldston et al.) motivating a further study examining the parameters which affect the N concentration required to reach detachment. Finally, the N concentrations from spectroscopy and the ratio of D and N gas valve fluxes agree within experimental uncertainty only when the vessel surfaces are fully-loaded with N.

AB - The impurity concentration in the tokamak divertor plasma is a necessary input for predictive scaling of divertor detachment, however direct measurements from existing tokamaks in different divertor plasma conditions are limited. To address this, we have applied a recently developed spectroscopic N II line ratio technique for measuring the N concentration in the divertor to a range of H-mode and L-mode plasma from the ASDEX Upgrade and JET tokamaks, respectively. The results from both devices show that as the power crossing the separatrix, Psep, is increased under otherwise similar core conditions (e.g. density), a higher N concentration is required to achieve the same detachment state. For example, the N concentrations at the start of detachment increase from ≈ 2% to ≈ 9% as Psep is increased from ≈ 2.5 MW to ≈ 7 MW. These results tentatively agree with scaling law predictions (e.g. Goldston et al.) motivating a further study examining the parameters which affect the N concentration required to reach detachment. Finally, the N concentrations from spectroscopy and the ratio of D and N gas valve fluxes agree within experimental uncertainty only when the vessel surfaces are fully-loaded with N.

KW - Concentration

KW - Divertor

KW - Impurity

KW - Nitrogen

KW - Spectroscopy

KW - Tokamak

UR - http://www.scopus.com/inward/record.url?scp=85058630263&partnerID=8YFLogxK

U2 - 10.1016/j.nme.2018.12.012

DO - 10.1016/j.nme.2018.12.012

M3 - Article

VL - 18

SP - 147

EP - 152

JO - Nuclear Materials and Energy

JF - Nuclear Materials and Energy

SN - 2352-1791

ER -