Impurity transport studies at Wendelstein 7-X by means of x-ray imaging spectrometer measurements

Research output: Contribution to journalJournal article – Annual report year: 2019Researchpeer-review

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Impurity transport studies at Wendelstein 7-X by means of x-ray imaging spectrometer measurements. / Langenberg, A.; Warmer, F.; Fuchert, G.; Marchuk, O.; Dinklage, A.; Wegner, Th; Alonso, J.A.; Bozhenkov, S.; Brunner, K. J.; Burhenn, R.; Buttenschön, B.; Drews, P.; Geiger, B.; Grulke, Olaf; Hirsch, M.; Höfel, U.; Hollfeld, K.P.; Killer, C.; Knauer, J.; Krings, T.; Kunkel, F.; Neuner, U.; Offermanns, G.; Pablant, N.A.; Pasch, E.; Rahbarnia, K.; Satheeswaran, G.; Schilling, J.; Schweer, B; Thomsen, H.; Traverso, P.; Wolf, R.C.

In: Plasma Physics and Controlled Fusion, Vol. 61, No. 1, 014030, 2019.

Research output: Contribution to journalJournal article – Annual report year: 2019Researchpeer-review

Harvard

Langenberg, A, Warmer, F, Fuchert, G, Marchuk, O, Dinklage, A, Wegner, T, Alonso, JA, Bozhenkov, S, Brunner, KJ, Burhenn, R, Buttenschön, B, Drews, P, Geiger, B, Grulke, O, Hirsch, M, Höfel, U, Hollfeld, KP, Killer, C, Knauer, J, Krings, T, Kunkel, F, Neuner, U, Offermanns, G, Pablant, NA, Pasch, E, Rahbarnia, K, Satheeswaran, G, Schilling, J, Schweer, B, Thomsen, H, Traverso, P & Wolf, RC 2019, 'Impurity transport studies at Wendelstein 7-X by means of x-ray imaging spectrometer measurements', Plasma Physics and Controlled Fusion, vol. 61, no. 1, 014030. https://doi.org/10.1088/1361-6587/aaeb74

APA

Langenberg, A., Warmer, F., Fuchert, G., Marchuk, O., Dinklage, A., Wegner, T., ... Wolf, R. C. (2019). Impurity transport studies at Wendelstein 7-X by means of x-ray imaging spectrometer measurements. Plasma Physics and Controlled Fusion, 61(1), [014030]. https://doi.org/10.1088/1361-6587/aaeb74

CBE

Langenberg A, Warmer F, Fuchert G, Marchuk O, Dinklage A, Wegner T, Alonso JA, Bozhenkov S, Brunner KJ, Burhenn R, Buttenschön B, Drews P, Geiger B, Grulke O, Hirsch M, Höfel U, Hollfeld KP, Killer C, Knauer J, Krings T, Kunkel F, Neuner U, Offermanns G, Pablant NA, Pasch E, Rahbarnia K, Satheeswaran G, Schilling J, Schweer B, Thomsen H, Traverso P, Wolf RC. 2019. Impurity transport studies at Wendelstein 7-X by means of x-ray imaging spectrometer measurements. Plasma Physics and Controlled Fusion. 61(1). https://doi.org/10.1088/1361-6587/aaeb74

MLA

Vancouver

Author

Langenberg, A. ; Warmer, F. ; Fuchert, G. ; Marchuk, O. ; Dinklage, A. ; Wegner, Th ; Alonso, J.A. ; Bozhenkov, S. ; Brunner, K. J. ; Burhenn, R. ; Buttenschön, B. ; Drews, P. ; Geiger, B. ; Grulke, Olaf ; Hirsch, M. ; Höfel, U. ; Hollfeld, K.P. ; Killer, C. ; Knauer, J. ; Krings, T. ; Kunkel, F. ; Neuner, U. ; Offermanns, G. ; Pablant, N.A. ; Pasch, E. ; Rahbarnia, K. ; Satheeswaran, G. ; Schilling, J. ; Schweer, B ; Thomsen, H. ; Traverso, P. ; Wolf, R.C. / Impurity transport studies at Wendelstein 7-X by means of x-ray imaging spectrometer measurements. In: Plasma Physics and Controlled Fusion. 2019 ; Vol. 61, No. 1.

Bibtex

@article{0c2e6f1bab1f48d3ba127bcc47ffa253,
title = "Impurity transport studies at Wendelstein 7-X by means of x-ray imaging spectrometer measurements",
abstract = "This paper reports on the effect of on- and off-axis heating power deposition on the impurity confinement in purely electron cyclotron resonance heated He plasmas on the stellarator Wendelstein 7-X. Therefore, impurity transport times τ I have been determined after Fe impurity injections by laser ablations and monitoring the temporal impurity emissivities by the x-ray imaging spectrometer HR-XIS. A significant increase of τ I has been observed when changing the power deposition from on- to off-axis heating with energy confinement times τ E being mainly unaffected. In addition, the scaling of impurity transport properties with respect to a variation of heating power P ECRH and electron density n e has been investigated by keeping the heating power deposition on-axis. The observed τ I scaling compares well to known τ I scaling laws observed in other machines. A comparison of τ I and τ E yields an averaged ratio of τ E /τ I  = 1.3 and transport times in the range of τ I  = 40–130 ms and τ E  = 40–190 ms. Comparing those absolute values to neoclassical predictions supports the recently observed nature of anomalous transport in Wendelstein 7-X, given within the up to now investigated operational parameters.",
keywords = "Impurity transport, Impurity confinement, Energy confinement, Imaging spectrometer, Laser blow-off, Plasma physics",
author = "A. Langenberg and F. Warmer and G. Fuchert and O. Marchuk and A. Dinklage and Th Wegner and J.A. Alonso and S. Bozhenkov and Brunner, {K. J.} and R. Burhenn and B. Buttensch{\"o}n and P. Drews and B. Geiger and Olaf Grulke and M. Hirsch and U. H{\"o}fel and K.P. Hollfeld and C. Killer and J. Knauer and T. Krings and F. Kunkel and U. Neuner and G. Offermanns and N.A. Pablant and E. Pasch and K. Rahbarnia and G. Satheeswaran and J. Schilling and B Schweer and H. Thomsen and P. Traverso and R.C. Wolf",
note = "Original content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.",
year = "2019",
doi = "10.1088/1361-6587/aaeb74",
language = "English",
volume = "61",
journal = "Plasma Physics and Controlled Fusion",
issn = "0741-3335",
publisher = "IOP Publishing",
number = "1",

}

RIS

TY - JOUR

T1 - Impurity transport studies at Wendelstein 7-X by means of x-ray imaging spectrometer measurements

AU - Langenberg, A.

AU - Warmer, F.

AU - Fuchert, G.

AU - Marchuk, O.

AU - Dinklage, A.

AU - Wegner, Th

AU - Alonso, J.A.

AU - Bozhenkov, S.

AU - Brunner, K. J.

AU - Burhenn, R.

AU - Buttenschön, B.

AU - Drews, P.

AU - Geiger, B.

AU - Grulke, Olaf

AU - Hirsch, M.

AU - Höfel, U.

AU - Hollfeld, K.P.

AU - Killer, C.

AU - Knauer, J.

AU - Krings, T.

AU - Kunkel, F.

AU - Neuner, U.

AU - Offermanns, G.

AU - Pablant, N.A.

AU - Pasch, E.

AU - Rahbarnia, K.

AU - Satheeswaran, G.

AU - Schilling, J.

AU - Schweer, B

AU - Thomsen, H.

AU - Traverso, P.

AU - Wolf, R.C.

N1 - Original content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.

PY - 2019

Y1 - 2019

N2 - This paper reports on the effect of on- and off-axis heating power deposition on the impurity confinement in purely electron cyclotron resonance heated He plasmas on the stellarator Wendelstein 7-X. Therefore, impurity transport times τ I have been determined after Fe impurity injections by laser ablations and monitoring the temporal impurity emissivities by the x-ray imaging spectrometer HR-XIS. A significant increase of τ I has been observed when changing the power deposition from on- to off-axis heating with energy confinement times τ E being mainly unaffected. In addition, the scaling of impurity transport properties with respect to a variation of heating power P ECRH and electron density n e has been investigated by keeping the heating power deposition on-axis. The observed τ I scaling compares well to known τ I scaling laws observed in other machines. A comparison of τ I and τ E yields an averaged ratio of τ E /τ I  = 1.3 and transport times in the range of τ I  = 40–130 ms and τ E  = 40–190 ms. Comparing those absolute values to neoclassical predictions supports the recently observed nature of anomalous transport in Wendelstein 7-X, given within the up to now investigated operational parameters.

AB - This paper reports on the effect of on- and off-axis heating power deposition on the impurity confinement in purely electron cyclotron resonance heated He plasmas on the stellarator Wendelstein 7-X. Therefore, impurity transport times τ I have been determined after Fe impurity injections by laser ablations and monitoring the temporal impurity emissivities by the x-ray imaging spectrometer HR-XIS. A significant increase of τ I has been observed when changing the power deposition from on- to off-axis heating with energy confinement times τ E being mainly unaffected. In addition, the scaling of impurity transport properties with respect to a variation of heating power P ECRH and electron density n e has been investigated by keeping the heating power deposition on-axis. The observed τ I scaling compares well to known τ I scaling laws observed in other machines. A comparison of τ I and τ E yields an averaged ratio of τ E /τ I  = 1.3 and transport times in the range of τ I  = 40–130 ms and τ E  = 40–190 ms. Comparing those absolute values to neoclassical predictions supports the recently observed nature of anomalous transport in Wendelstein 7-X, given within the up to now investigated operational parameters.

KW - Impurity transport

KW - Impurity confinement

KW - Energy confinement

KW - Imaging spectrometer

KW - Laser blow-off

KW - Plasma physics

U2 - 10.1088/1361-6587/aaeb74

DO - 10.1088/1361-6587/aaeb74

M3 - Journal article

VL - 61

JO - Plasma Physics and Controlled Fusion

JF - Plasma Physics and Controlled Fusion

SN - 0741-3335

IS - 1

M1 - 014030

ER -