Direct measurements of counter-streaming flows in a low-shear stellarator magnetic island topology

Perseo, Valeria; Effenberg, F.; Gradic, D.; König, R.; Ford, O. P.; Reimold, F.; Ennis, D. A.; Schmitz, O.; Sunn Pedersen, T.

doi:10.1088/1741-4326/ab4320

Title: Direct measurements of counter-streaming flows in a low-shear stellarator magnetic island topology

Journal Article · 25 September 2019 · Nuclear Fusion

DOI: https://doi.org/10.1088/1741-4326/ab4320 · OSTI ID:1572710

^[1];

^[2];

^[1]; König, R. ^[1]; Ford, O. P. ^[1]; Reimold, F. ^[1]; Ennis, D. A. ^[3]; Schmitz, O. ^[4];

^[1]

Max-Planck-Institut für Plasmaphysik, Greifswald (Germany)
Univ. of Wisconsin, Madison, WI (United States); Princeton Univ., NJ (United States)
Auburn Univ., Auburn, AL (United States)
Univ. of Wisconsin, Madison, WI (United States)

We report on the first experimental verification of theoretically predicted multiple bundles of counter-streaming plasma flows in the island-divertor scrape-off layer (SOL) of the stellarator Wendelstein 7-X. In the standard toroidal field direction (counter-clockwise when looking from the top) experiments, the overall structure of the SOL flows, such as flow directions, the number of flow bundles and the magnitude of the flow velocities, are consistent with numerical predictions obtained with EMC3-EIRENE. However, the modelling does not predict changes of the flow patterns with reversal of the magnetic field direction, which are experimentally observed. This indicates that additional relevant physics, such as particle drifts, will need to be incorporated into the numerical model to better describe the whole stellarator scrape-off layer behaviour.

View Accepted Manuscript (DOE)

Cite

Export

Save

Research Organization:: Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)

Sponsoring Organization:: USDOE

Contributing Organization:: the W7-X Team

Grant/Contract Number:: SC0014210; SC0014529

OSTI ID:: 1572710

Journal Information:: Nuclear Fusion, Journal Name: Nuclear Fusion Journal Issue: 12 Vol. 59; ISSN 0029-5515

Publisher:: IOP ScienceCopyright Statement

Country of Publication:: United States

Language:: English

References (64)

Coherence Imaging of Flows in the DIII-D Divertor Howard, J.; Diallo, A.; Creese, M. Contributions to Plasma Physics, Vol. 51, Issue 2-3 https://doi.org/10.1002/ctpp.201000062	journal	March 2011
The effect of divertor magnetic balance on H-mode performance in DIII-D Petrie, T. W.; Greenfield, C. M.; Grobener, R. J. Journal of Nuclear Materials, Vol. 290-293 https://doi.org/10.1016/S0022-3115(00)00492-X	journal	March 2001
Modelling of island divertor physics and comparison to W7-AS experimental results Feng, Y.; Sardei, F.; Grigull, P. Journal of Nuclear Materials, Vol. 313-316 https://doi.org/10.1016/S0022-3115(02)01463-0	journal	March 2003
Influence of magnetic field configurations on divertor plasma parameters in the W7-AS stellarator Grigull, P.; McCormick, K.; Feng, Y. Journal of Nuclear Materials, Vol. 313-316 https://doi.org/10.1016/S0022-3115(02)01499-X	journal	March 2003
Classical drifts in the tokamak SOL and divertor: models and experiment Chankin, A. V. Journal of Nuclear Materials, Vol. 241-243 https://doi.org/10.1016/S0022-3115(97)80040-2	journal	February 1997
Drift effects in W7-AS limiter and island divertor configurations Feng, Y.; Sardei, F.; Grigull, P. Journal of Nuclear Materials, Vol. 266-269 https://doi.org/10.1016/S0022-3115(98)00622-9	journal	March 1999
3D fluid modelling of the edge plasma by means of a Monte Carlo technique Feng, Y.; Sardei, F.; Kisslinger, J. Journal of Nuclear Materials, Vol. 266-269 https://doi.org/10.1016/S0022-3115(98)00844-7	journal	March 1999
Divertor operation in stellarators: results from W7-AS and implications for future devices Grigull, P.; McCormick, K.; Renner, H. Fusion Engineering and Design, Vol. 66-68 https://doi.org/10.1016/S0920-3796(03)00121-2	journal	September 2003
A new calibration implementation for Doppler Coherence Imaging Spectroscopy Gradic, Dorothea; Perseo, Valeria; König, Ralf Fusion Engineering and Design, Vol. 146 https://doi.org/10.1016/j.fusengdes.2019.01.138	journal	September 2019
Neutral pressure behavior for diverted discharges in the Wendelstein 7-AS Stellarator McCormick, K.; Grigull, P.; Burhenn, R. Journal of Nuclear Materials, Vol. 337-339 https://doi.org/10.1016/j.jnucmat.2004.10.052	journal	March 2005
Local island divertor experiments on LHD Morisaki, T.; Masuzaki, S.; Komori, A. Journal of Nuclear Materials, Vol. 337-339 https://doi.org/10.1016/j.jnucmat.2004.10.165	journal	March 2005
Divertor transport study in the large helical device Kobayashi, M.; Feng, Y.; Masuzaki, S. Journal of Nuclear Materials, Vol. 363-365 https://doi.org/10.1016/j.jnucmat.2007.01.038	journal	June 2007
Particle transport measurements in the LHD stochastic magnetic boundary plasma using Mach probes and ion sensitive probe Ezumi, N.; Todoroki, K.; Kobayashi, T. Journal of Nuclear Materials, Vol. 415, Issue 1 https://doi.org/10.1016/j.jnucmat.2010.10.040	journal	August 2011
Tungsten as material for plasma-facing components in fusion devices Philipps, V. Journal of Nuclear Materials, Vol. 415, Issue 1 https://doi.org/10.1016/j.jnucmat.2011.01.110	journal	August 2011
2D distribution of hydrogen/impurity radiation and flow formation in stochastic layer during detachment transition in LHD Kobayashi, M.; Morita, S.; Goto, M. Nuclear Materials and Energy, Vol. 12 https://doi.org/10.1016/j.nme.2016.12.023	journal	August 2017
Power exhaust by SOL and pedestal radiation at ASDEX Upgrade and JET Bernert, M.; Wischmeier, M.; Huber, A. Nuclear Materials and Energy, Vol. 12 https://doi.org/10.1016/j.nme.2016.12.029	journal	August 2017
Investigation of 3D effects on heat fluxes in performance-optimized island divertor configurations at Wendelstein 7-X Effenberg, F.; Niemann, H.; Feng, Y. Nuclear Materials and Energy, Vol. 18 https://doi.org/10.1016/j.nme.2019.01.006	journal	January 2019
Classical drifts in the tokamak SOL and divertor: models and experiment Chankin, A. Journal of Nuclear Materials, Vol. 241-243, Issue 1 https://doi.org/10.1016/s0022-3115(96)00505-3	journal	February 1997
Novel scanning interferometer for two‐dimensional plasma density measurements Howard, John Review of Scientific Instruments, Vol. 61, Issue 3 https://doi.org/10.1063/1.1141428	journal	March 1990
Doppler coherence imaging and tomography of flows in tokamak plasmas (invited) Howard, J.; Diallo, A.; Creese, M. Review of Scientific Instruments, Vol. 81, Issue 10 https://doi.org/10.1063/1.3492422	journal	October 2010
Coherence imaging of scrape-off-layer and divertor impurity flows in the Mega Amp Spherical Tokamak (invited) Silburn, S. A.; Harrison, J. R.; Howard, J. Review of Scientific Instruments, Vol. 85, Issue 11 https://doi.org/10.1063/1.4891165	journal	November 2014
Synthetic plasma edge diagnostics for EMC3-EIRENE, highlighted for Wendelstein 7-X Frerichs, H.; Effenberg, F.; Schmitz, O. Review of Scientific Instruments, Vol. 87, Issue 11 https://doi.org/10.1063/1.4959910	journal	September 2016
Space-resolved visible spectroscopy for two-dimensional measurement of hydrogen and impurity emission spectra and of plasma flow in the edge stochastic layer of LHD Kobayashi, M.; Morita, S.; Goto, M. Review of Scientific Instruments, Vol. 88, Issue 3 https://doi.org/10.1063/1.4976963	journal	March 2017
Vertical profiles and two-dimensional distributions of carbon line emissions from C ²⁺ −C ⁵⁺ ions in attached and RMP-assisted detached plasmas of large helical device Zhang, Hongming; Morita, Shigeru; Dai, Shuyu Physics of Plasmas, Vol. 24, Issue 2 https://doi.org/10.1063/1.4976989	journal	February 2017
HSX as an example of a resilient non-resonant divertor Bader, A.; Boozer, A. H.; Hegna, C. C. Physics of Plasmas, Vol. 24, Issue 3 https://doi.org/10.1063/1.4978494	journal	March 2017
2D imaging of helium ion velocity in the DIII-D divertor Samuell, C. M.; Porter, G. D.; Meyer, W. H. Physics of Plasmas, Vol. 25, Issue 5 https://doi.org/10.1063/1.5017999	journal	May 2018
Laser calibration of the DIII-D coherence imaging system Allen, S. L.; Samuell, C. M.; Meyer, W. H. Review of Scientific Instruments, Vol. 89, Issue 10 https://doi.org/10.1063/1.5038739	journal	October 2018
Verification of Doppler coherence imaging for 2D ion velocity measurements on DIII-D Samuell, C. M.; Allen, S. L.; Meyer, W. H. Review of Scientific Instruments, Vol. 89, Issue 9 https://doi.org/10.1063/1.5039367	journal	September 2018
Simulation of stellarator divertors Boozer, Allen H.; Punjabi, Alkesh Physics of Plasmas, Vol. 25, Issue 9 https://doi.org/10.1063/1.5042666	journal	September 2018
Particle and power exhaust for a fusion plasma Behrisch, R.; Prozesky, V. Nuclear Fusion, Vol. 30, Issue 10 https://doi.org/10.1088/0029-5515/30/10/015	journal	October 1990
Chapter 4: Power and particle control Divertor, ITER Physics Expert Group on; Database, ITER Physics Expert Group on Divert; Editors, ITER Physics Basis Nuclear Fusion, Vol. 39, Issue 12 https://doi.org/10.1088/0029-5515/39/12/304	journal	December 1999
Transport-driven Scrape-Off-Layer flows and the boundary conditions imposed at the magnetic separatrix in a tokamak plasma LaBombard, B.; Rice, J. E.; Hubbard, A. E. Nuclear Fusion, Vol. 44, Issue 10 https://doi.org/10.1088/0029-5515/44/10/001	journal	September 2004
Physics of island divertors as highlighted by the example of W7-AS Feng, Y.; Sardei, F.; Grigull, P. Nuclear Fusion, Vol. 46, Issue 8 https://doi.org/10.1088/0029-5515/46/8/006	journal	July 2006
Chapter 4: Power and particle control Loarte, A.; Lipschultz, B.; Kukushkin, A. S. Nuclear Fusion, Vol. 47, Issue 6 https://doi.org/10.1088/0029-5515/47/6/S04	journal	June 2007
Fluid features of the stochastic layer transport in LHD Feng, Y.; Kobayashi, M.; Morisaki, T. Nuclear Fusion, Vol. 48, Issue 2 https://doi.org/10.1088/0029-5515/48/2/024012	journal	January 2008
Comparative divertor-transport study for helical devices Feng, Y.; Kobayashi, M.; Sardei, F. Nuclear Fusion, Vol. 49, Issue 9 https://doi.org/10.1088/0029-5515/49/9/095002	journal	August 2009
Effective screening of iron impurities in the ergodic layer of the Large Helical Device with a metallic first wall Morita, S.; Dong, C. F.; Kobayashi, M. Nuclear Fusion, Vol. 53, Issue 9 https://doi.org/10.1088/0029-5515/53/9/093017	journal	August 2013
Divertor studies in nitrogen induced completely detached H-modes in full tungsten ASDEX Upgrade Reimold, F.; Wischmeier, M.; Bernert, M. Nuclear Fusion, Vol. 55, Issue 3 https://doi.org/10.1088/0029-5515/55/3/033004	journal	February 2015
Experimental divertor physics Pitcher, C. S.; Stangeby, P. C. Plasma Physics and Controlled Fusion, Vol. 39, Issue 6 https://doi.org/10.1088/0741-3335/39/6/001	journal	June 1997
The effects of field reversal on the W7-AS island divertor at low densities Feng, Y.; Herre, G.; Grigull, P. Plasma Physics and Controlled Fusion, Vol. 40, Issue 3 https://doi.org/10.1088/0741-3335/40/3/003	journal	March 1998
The Plasma Boundary of Magnetic Fusion Devices Ghendrih, Philippe Plasma Physics and Controlled Fusion, Vol. 43, Issue 2 https://doi.org/10.1088/0741-3335/43/2/702	journal	January 2001
The divertor program in stellarators K. nig, R.; Grigull, P.; McCormick, K. Plasma Physics and Controlled Fusion, Vol. 44, Issue 11 https://doi.org/10.1088/0741-3335/44/11/306	journal	October 2002
Transport in island divertors: physics, 3D modelling and comparison to first experiments on W7-AS* Feng, Y.; Sardei, F.; Grigull, P. Plasma Physics and Controlled Fusion, Vol. 44, Issue 5 https://doi.org/10.1088/0741-3335/44/5/308	journal	May 2002
Time-resolved two-dimensional plasma spectroscopy using coherence-imaging techniques Howard, J.; Michael, C.; Glass, F. Plasma Physics and Controlled Fusion, Vol. 45, Issue 7 https://doi.org/10.1088/0741-3335/45/7/308	journal	May 2003
Major results from the stellarator Wendelstein 7-AS Hirsch, M.; Baldzuhn, J.; Beidler, C. Plasma Physics and Controlled Fusion, Vol. 50, Issue 5 https://doi.org/10.1088/0741-3335/50/5/053001	journal	March 2008
Comparison between stellarator and tokamak divertor transport Feng, Y.; Kobayashi, M.; Lunt, T. Plasma Physics and Controlled Fusion, Vol. 53, Issue 2 https://doi.org/10.1088/0741-3335/53/2/024009	journal	January 2011
Two-dimensional study of edge impurity transport in the Large Helical Device Morita, S.; Wang, E. H.; Kobayashi, M. Plasma Physics and Controlled Fusion, Vol. 56, Issue 9 https://doi.org/10.1088/0741-3335/56/9/094007	journal	August 2014
Three-dimensional scrape off layer transport in the helically symmetric experiment HSX Akerson, A. R.; Bader, A.; Hegna, C. C. Plasma Physics and Controlled Fusion, Vol. 58, Issue 8 https://doi.org/10.1088/0741-3335/58/8/084002	journal	June 2016
Coherence imaging spectro-polarimetry for magnetic fusion diagnostics Howard, J. Journal of Physics B: Atomic, Molecular and Optical Physics, Vol. 43, Issue 14 https://doi.org/10.1088/0953-4075/43/14/144010	journal	July 2010
Doppler coherence imaging of divertor and SOL flows in ASDEX upgrade and Wendelstein 7-X Gradic, D.; Ford, O. P.; Burckhart, A. Plasma Physics and Controlled Fusion, Vol. 60, Issue 8 https://doi.org/10.1088/1361-6587/aac4d2	journal	June 2018
Numerical investigation of plasma edge transport and limiter heat fluxes in Wendelstein 7-X startup plasmas with EMC3-EIRENE Effenberg, F.; Feng, Y.; Schmitz, O. Nuclear Fusion, Vol. 57, Issue 3 https://doi.org/10.1088/1741-4326/aa4f83	journal	January 2017
Absolute calibration of Doppler coherence imaging velocity images Samuell, C. M.; Allen, S. L.; Meyer, W. H. Journal of Instrumentation, Vol. 12, Issue 08 https://doi.org/10.1088/1748-0221/12/08/C08016	journal	August 2017
Experimental Investigation of the Magnetic Configuration Dependence of Turbulent Transport Birkenmeier, G.; Ramisch, M.; Manz, P. Physical Review Letters, Vol. 107, Issue 2 https://doi.org/10.1103/PhysRevLett.107.025001	journal	July 2011
Inter-ELM Power Decay Length for JET and ASDEX Upgrade: Measurement and Comparison with Heuristic Drift-Based Model Eich, T.; Sieglin, B.; Scarabosio, A. Physical Review Letters, Vol. 107, Issue 21 https://doi.org/10.1103/PhysRevLett.107.215001	journal	November 2011
Sustained Stabilization of the Resistive-Wall Mode by Plasma Rotation in the DIII-D Tokamak Garofalo, A. M.; Strait, E. J.; Johnson, L. C. Physical Review Letters, Vol. 89, Issue 23 https://doi.org/10.1103/PhysRevLett.89.235001	journal	November 2002
The Plasma Boundary of Magnetic Fusion Devices Stangeby, P. Series in Plasma Physics https://doi.org/10.1201/9781420033328	book	January 2000
Armour Materials for the ITER Plasma Facing Components Barabash, V.; Federici, G.; Matera, R. Physica Scripta, Vol. T81, Issue 1 https://doi.org/10.1238/Physica.Topical.081a00074	journal	January 1999
Divertors for Helical Devices: Concepts, Plans, Results, and Problems König, R.; Grigull, P.; McCormick, K. Fusion Science and Technology, Vol. 46, Issue 1 https://doi.org/10.13182/FST04-A551	journal	July 2004
Physical Aspects and Design of the Wendelstein 7-X Divertor Renner, Hermann; Sharma, Devendra; Kißlinger, Johann Fusion Science and Technology, Vol. 46, Issue 2 https://doi.org/10.13182/FST04-A570	journal	September 2004
High Heat Flux Performance of Plasma Facing Materials and Components under Service Conditions in Future Fusion Reactors Linke, Jochen Fusion Science and Technology, Vol. 49, Issue 2T https://doi.org/10.13182/FST06-A1144	journal	February 2006
The EIRENE and B2-EIRENE Codes Reiter, D.; Baelmans, M.; Börner, P. Fusion Science and Technology, Vol. 47, Issue 2 https://doi.org/10.13182/FST47-172	journal	February 2005
High Heat Flux Performance of Plasma Facing Materials and Components Under Service Conditions in Future Fusion Reactors Jochen, Linke Fusion Science and Technology, Vol. 53, Issue 2T https://doi.org/10.13182/fst08-a1713	journal	February 2008
High Heat Flux Performance of Plasma Facing Materials and Components under Service Conditions in Future Fusion Reactors Linke, Jochen Fusion Science and Technology, Vol. 57, Issue 2T https://doi.org/10.13182/fst10-a9420	journal	February 2010
The Plasma Boundary of Magnetic Fusion Devices Stangeby, Peter C. Plasma Physics and Controlled Fusion, Vol. 43, Issue 2 https://doi.org/10.1887/0750305592	book	January 2000

Cited By (2)

Coherence imaging spectroscopy at Wendelstein 7-X for impurity flow measurements Perseo, Valeria; Gradic, Dorothea; König, Ralf Review of Scientific Instruments, Vol. 91, Issue 1 https://doi.org/10.1063/1.5126098	journal	January 2020
Effect of toroidal plasma currents on the Wendelstein 7-X Scrape-Off Layer Killer, Carsten; Gao, Yu; Perseo, Valeria Plasma Physics and Controlled Fusion, Vol. 61, Issue 12 https://doi.org/10.1088/1361-6587/ab4f2d	journal	November 2019

Similar Records

Doppler coherence imaging of divertor and SOL flows in ASDEX upgrade and Wendelstein 7-X

Journal Article · 2018 · Plasma Physics and Controlled Fusion · OSTI ID:1499869

Gradic, D.; Ford, O. P.; Burckhart, A.; +6 more

First experimental confirmation of island SOL geometry effects in a high radiation regime on W7-X

Journal Article · 2024 · Nuclear Fusion · OSTI ID:2452824

Winters, Victoria; Reimold, Felix; Feng, Yühe; +13 more

2D measurements of parallel counter-streaming flows in the W7-X scrape-off layer for attached and detached plasmas

Journal Article · 2021 · Nuclear Fusion · OSTI ID:1825332

Perseo, V.; Winters, V.; Feng, Y.; +27 more

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
coherence imaging spectroscopy
impurity transport
island divertor
magnetic islands
plasma flows
scrape-off layer

Title: Direct measurements of counter-streaming flows in a low-shear stellarator magnetic island topology

Citation Formats

References (64)

Cited By (2)

Similar Records

Related Subjects