Electron-cyclotron-resonance heating in Wendelstein 7-X: A versatile heating and current-drive method and a tool for in-depth physics studies

Paper

Wendelstein 7-X Team, R C Wolf*, S Bozhenkov, A Dinklage, G Fuchert, Y O Kazakov, H P Laqua, S Marsen, N B Marushchenko, T Stange, M Zanini, I Abramovic, A Alonso, J Baldzuhn, M Beurskens, C D Beidler, H Braune, K J Brunner, N Chaudhary, H Damm & 35 others P Drewelow, G Gantenbein, Yu Gao, J Geiger, M Hirsch, U Höfel, M Jakubowski, J Jelonnek, T Jensen, W Kasparek, J Knauer, Søren Bang Korsholm, A Langenberg, C Lechte, F. Leipold, H Trimino Mora, U Neuner, S. K. Nielsen, D Moseev, H Oosterbeek, N Pablant, E Pasch, B Plaum, T Sunn Pedersen, A Puig Sitjes, K Rahbarnia, J. Rasmussen, M. Salewski, J Schilling, E Scott, M. Stejner, H Thomsen, M Thumm, Y Turkin, F Wilde

*Corresponding author for this work

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Abstract

For stellarators, which need no or only small amounts of current drive, electron-cyclotron-resonance heating (ECRH) is a promising heating method even for the envisaged application in a fusion power plant. Wendelstein 7-X (W7-X) is equipped with a steady-state capable ECRH system, operating at 140 GHz, which corresponds to the 2nd cyclotron harmonic of the electrons at a magnetic field of 2.5 T. Ten gyrotrons are operational and already delivered 7 MW to W7-X plasmas. Combined with pellet injection, the highest triple product (0.68 × 1020 keV m−3 s), observed up to now in stellarators, was achieved (Sunn Pedersen et al 2018 Plasma Phys. Control. Fusion 61 014035). For the first time, W7-X plasmas were sustained by 2nd harmonic O-mode heating, approaching the collisionality regime for which W7-X was optimized. Power deposition scans did not show any indication of electron temperature profile resilience. In low-density, low-power plasmas a compensation of the bootstrap current with electron-cyclotron current drive (ECCD) was demonstrated. Sufficiently strong ECCD close to the plasma centre produced periodic internal plasma-crash events, which coincide with the appearance of low order rationals of the rotational transform.
Original languageEnglish
Article number014037
JournalPlasma Physics and Controlled Fusion
Volume61
Issue number1
Number of pages9
ISSN0741-3335
DOIs
Publication statusPublished - 2019
Event45th EPS Conference on Plasma Physics - Prague, Czech Republic
Duration: 2 Jul 20186 Jul 2018

Conference

Conference45th EPS Conference on Plasma Physics
CountryCzech Republic
CityPrague
Period02/07/201806/07/2018

Keywords

  • Stellerator
  • Wendelstein 7-X
  • Electron-cyclotron-resonance heating and current drive

Cite this

Wendelstein 7-X Team ; Wolf, R C ; Bozhenkov, S ; Dinklage, A ; Fuchert, G ; Kazakov, Y O ; Laqua, H P ; Marsen, S ; Marushchenko, N B ; Stange, T ; Zanini, M ; Abramovic, I ; Alonso, A ; Baldzuhn, J ; Beurskens, M ; Beidler, C D ; Braune, H ; Brunner, K J ; Chaudhary, N ; Damm, H ; Drewelow, P ; Gantenbein, G ; Gao, Yu ; Geiger, J ; Hirsch, M ; Höfel, U ; Jakubowski, M ; Jelonnek, J ; Jensen, T ; Kasparek, W ; Knauer, J ; Korsholm, Søren Bang ; Langenberg, A ; Lechte, C ; Leipold, F. ; Mora, H Trimino ; Neuner, U ; Nielsen, S. K. ; Moseev, D ; Oosterbeek, H ; Pablant, N ; Pasch, E ; Plaum, B ; Pedersen, T Sunn ; Sitjes, A Puig ; Rahbarnia, K ; Rasmussen, J. ; Salewski, M. ; Schilling, J ; Scott, E ; Stejner, M. ; Thomsen, H ; Thumm, M ; Turkin, Y ; Wilde, F. / Electron-cyclotron-resonance heating in Wendelstein 7-X: A versatile heating and current-drive method and a tool for in-depth physics studies : Paper. In: Plasma Physics and Controlled Fusion. 2019 ; Vol. 61, No. 1.
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title = "Electron-cyclotron-resonance heating in Wendelstein 7-X: A versatile heating and current-drive method and a tool for in-depth physics studies: Paper",
abstract = "For stellarators, which need no or only small amounts of current drive, electron-cyclotron-resonance heating (ECRH) is a promising heating method even for the envisaged application in a fusion power plant. Wendelstein 7-X (W7-X) is equipped with a steady-state capable ECRH system, operating at 140 GHz, which corresponds to the 2nd cyclotron harmonic of the electrons at a magnetic field of 2.5 T. Ten gyrotrons are operational and already delivered 7 MW to W7-X plasmas. Combined with pellet injection, the highest triple product (0.68 × 1020 keV m−3 s), observed up to now in stellarators, was achieved (Sunn Pedersen et al 2018 Plasma Phys. Control. Fusion 61 014035). For the first time, W7-X plasmas were sustained by 2nd harmonic O-mode heating, approaching the collisionality regime for which W7-X was optimized. Power deposition scans did not show any indication of electron temperature profile resilience. In low-density, low-power plasmas a compensation of the bootstrap current with electron-cyclotron current drive (ECCD) was demonstrated. Sufficiently strong ECCD close to the plasma centre produced periodic internal plasma-crash events, which coincide with the appearance of low order rationals of the rotational transform.",
keywords = "Stellerator, Wendelstein 7-X, Electron-cyclotron-resonance heating and current drive",
author = "{Wendelstein 7-X Team} and Wolf, {R C} and S Bozhenkov and A Dinklage and G Fuchert and Kazakov, {Y O} and Laqua, {H P} and S Marsen and Marushchenko, {N B} and T Stange and M Zanini and I Abramovic and A Alonso and J Baldzuhn and M Beurskens and Beidler, {C D} and H Braune and Brunner, {K J} and N Chaudhary and H Damm and P Drewelow and G Gantenbein and Yu Gao and J Geiger and M Hirsch and U H{\"o}fel and M Jakubowski and J Jelonnek and T Jensen and W Kasparek and J Knauer and Korsholm, {S{\o}ren Bang} and A Langenberg and C Lechte and F. Leipold and Mora, {H Trimino} and U Neuner and Nielsen, {S. K.} and D Moseev and H Oosterbeek and N Pablant and E Pasch and B Plaum and Pedersen, {T Sunn} and Sitjes, {A Puig} and K Rahbarnia and J. Rasmussen and M. Salewski and J Schilling and E Scott and M. Stejner and H Thomsen and M Thumm and Y Turkin and F Wilde",
year = "2019",
doi = "10.1088/1361-6587/aaeab2",
language = "English",
volume = "61",
journal = "Plasma Physics and Controlled Fusion",
issn = "0741-3335",
publisher = "IOP Publishing",
number = "1",

}

Wendelstein 7-X Team, Wolf, RC, Bozhenkov, S, Dinklage, A, Fuchert, G, Kazakov, YO, Laqua, HP, Marsen, S, Marushchenko, NB, Stange, T, Zanini, M, Abramovic, I, Alonso, A, Baldzuhn, J, Beurskens, M, Beidler, CD, Braune, H, Brunner, KJ, Chaudhary, N, Damm, H, Drewelow, P, Gantenbein, G, Gao, Y, Geiger, J, Hirsch, M, Höfel, U, Jakubowski, M, Jelonnek, J, Jensen, T, Kasparek, W, Knauer, J, Korsholm, SB, Langenberg, A, Lechte, C, Leipold, F, Mora, HT, Neuner, U, Nielsen, SK, Moseev, D, Oosterbeek, H, Pablant, N, Pasch, E, Plaum, B, Pedersen, TS, Sitjes, AP, Rahbarnia, K, Rasmussen, J, Salewski, M, Schilling, J, Scott, E, Stejner, M, Thomsen, H, Thumm, M, Turkin, Y & Wilde, F 2019, 'Electron-cyclotron-resonance heating in Wendelstein 7-X: A versatile heating and current-drive method and a tool for in-depth physics studies: Paper', Plasma Physics and Controlled Fusion, vol. 61, no. 1, 014037. https://doi.org/10.1088/1361-6587/aaeab2

Electron-cyclotron-resonance heating in Wendelstein 7-X: A versatile heating and current-drive method and a tool for in-depth physics studies : Paper. / Wendelstein 7-X Team; Wolf, R C; Bozhenkov, S; Dinklage, A; Fuchert, G; Kazakov, Y O; Laqua, H P; Marsen, S; Marushchenko, N B; Stange, T; Zanini, M; Abramovic, I; Alonso, A; Baldzuhn, J; Beurskens, M; Beidler, C D; Braune, H; Brunner, K J; Chaudhary, N; Damm, H; Drewelow, P; Gantenbein, G; Gao, Yu; Geiger, J; Hirsch, M; Höfel, U; Jakubowski, M; Jelonnek, J; Jensen, T; Kasparek, W; Knauer, J; Korsholm, Søren Bang; Langenberg, A; Lechte, C; Leipold, F.; Mora, H Trimino; Neuner, U; Nielsen, S. K.; Moseev, D; Oosterbeek, H; Pablant, N; Pasch, E; Plaum, B; Pedersen, T Sunn; Sitjes, A Puig; Rahbarnia, K; Rasmussen, J.; Salewski, M.; Schilling, J; Scott, E; Stejner, M. ; Thomsen, H; Thumm, M; Turkin, Y; Wilde, F.

In: Plasma Physics and Controlled Fusion, Vol. 61, No. 1, 014037, 2019.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Electron-cyclotron-resonance heating in Wendelstein 7-X: A versatile heating and current-drive method and a tool for in-depth physics studies

T2 - Paper

AU - Wendelstein 7-X Team

AU - Wolf, R C

AU - Bozhenkov, S

AU - Dinklage, A

AU - Fuchert, G

AU - Kazakov, Y O

AU - Laqua, H P

AU - Marsen, S

AU - Marushchenko, N B

AU - Stange, T

AU - Zanini, M

AU - Abramovic, I

AU - Alonso, A

AU - Baldzuhn, J

AU - Beurskens, M

AU - Beidler, C D

AU - Braune, H

AU - Brunner, K J

AU - Chaudhary, N

AU - Damm, H

AU - Drewelow, P

AU - Gantenbein, G

AU - Gao, Yu

AU - Geiger, J

AU - Hirsch, M

AU - Höfel, U

AU - Jakubowski, M

AU - Jelonnek, J

AU - Jensen, T

AU - Kasparek, W

AU - Knauer, J

AU - Korsholm, Søren Bang

AU - Langenberg, A

AU - Lechte, C

AU - Leipold, F.

AU - Mora, H Trimino

AU - Neuner, U

AU - Nielsen, S. K.

AU - Moseev, D

AU - Oosterbeek, H

AU - Pablant, N

AU - Pasch, E

AU - Plaum, B

AU - Pedersen, T Sunn

AU - Sitjes, A Puig

AU - Rahbarnia, K

AU - Rasmussen, J.

AU - Salewski, M.

AU - Schilling, J

AU - Scott, E

AU - Stejner, M.

AU - Thomsen, H

AU - Thumm, M

AU - Turkin, Y

AU - Wilde, F

PY - 2019

Y1 - 2019

N2 - For stellarators, which need no or only small amounts of current drive, electron-cyclotron-resonance heating (ECRH) is a promising heating method even for the envisaged application in a fusion power plant. Wendelstein 7-X (W7-X) is equipped with a steady-state capable ECRH system, operating at 140 GHz, which corresponds to the 2nd cyclotron harmonic of the electrons at a magnetic field of 2.5 T. Ten gyrotrons are operational and already delivered 7 MW to W7-X plasmas. Combined with pellet injection, the highest triple product (0.68 × 1020 keV m−3 s), observed up to now in stellarators, was achieved (Sunn Pedersen et al 2018 Plasma Phys. Control. Fusion 61 014035). For the first time, W7-X plasmas were sustained by 2nd harmonic O-mode heating, approaching the collisionality regime for which W7-X was optimized. Power deposition scans did not show any indication of electron temperature profile resilience. In low-density, low-power plasmas a compensation of the bootstrap current with electron-cyclotron current drive (ECCD) was demonstrated. Sufficiently strong ECCD close to the plasma centre produced periodic internal plasma-crash events, which coincide with the appearance of low order rationals of the rotational transform.

AB - For stellarators, which need no or only small amounts of current drive, electron-cyclotron-resonance heating (ECRH) is a promising heating method even for the envisaged application in a fusion power plant. Wendelstein 7-X (W7-X) is equipped with a steady-state capable ECRH system, operating at 140 GHz, which corresponds to the 2nd cyclotron harmonic of the electrons at a magnetic field of 2.5 T. Ten gyrotrons are operational and already delivered 7 MW to W7-X plasmas. Combined with pellet injection, the highest triple product (0.68 × 1020 keV m−3 s), observed up to now in stellarators, was achieved (Sunn Pedersen et al 2018 Plasma Phys. Control. Fusion 61 014035). For the first time, W7-X plasmas were sustained by 2nd harmonic O-mode heating, approaching the collisionality regime for which W7-X was optimized. Power deposition scans did not show any indication of electron temperature profile resilience. In low-density, low-power plasmas a compensation of the bootstrap current with electron-cyclotron current drive (ECCD) was demonstrated. Sufficiently strong ECCD close to the plasma centre produced periodic internal plasma-crash events, which coincide with the appearance of low order rationals of the rotational transform.

KW - Stellerator

KW - Wendelstein 7-X

KW - Electron-cyclotron-resonance heating and current drive

U2 - 10.1088/1361-6587/aaeab2

DO - 10.1088/1361-6587/aaeab2

M3 - Journal article

VL - 61

JO - Plasma Physics and Controlled Fusion

JF - Plasma Physics and Controlled Fusion

SN - 0741-3335

IS - 1

M1 - 014037

ER -