2D coherence imaging measurements of C 2+ ion temperatures in the divertor of Wendelstein 7-X

Gradic, D.; Perseo, V.; Kriete, D. M.; Krychowiak, M.; König, R.; Feng, Y.; Otte, M.; Pedersen, T. Sunn; Gao, Y.; Jakubowski, M.; Schlisio, G.; Warmer, F.; W7-X Team, the

doi:10.1088/1741-4326/ac25bf

Title: 2D coherence imaging measurements of C ²⁺ ion temperatures in the divertor of Wendelstein 7-X

Journal Article · Fri Oct 08 00:00:00 EDT 2021 · Nuclear Fusion

DOI:https://doi.org/10.1088/1741-4326/ac25bf· OSTI ID:1825331

;

; Krychowiak, M.; König, R.; Feng, Y.; Otte, M.;

;

; W7-X Team, the

For the first time, 2D ion temperature values are derived from coherence imaging spectroscopy (CIS) fringe contrast measurements by taking Zeeman line broadening effects into account during the analysis procedure of a spatial-heterodyne CIS instrument. This allowed 2D images of C²⁺ ion temperatures (T_i) across the 3D-shaped island divertor of the Wendelstein 7-X stellarator. Ion temperatures ranging from 10 to 20 eV are observed for the C²⁺ impurity species in the region above the divertor targets. During the transition from the attached to the detached plasma state, the C²⁺ radiation zone moves from close to the divertor target towards the last closed flux surface. Within this radiation zone, C²⁺ temperature does not decrease significantly. Experimentally, the coherence imaging measurements were cross-calibrated at one poloidal cross-section using a high resolution Echelle spectrometer, that shared its sightlines with the coherence imaging diagnostic. The spectra demonstrated that, apart from Doppler broadening, the Zeeman effect significantly contributes to the spectral line broadening and cannot be neglected when analyzing the CIS contrast data for T_i extraction in the edge and scrape-off-layer of Wendelstein 7-X (W7-X), due to the relatively low temperatures (T_i < 100 eV) and high magnetic fields (B ≈ 2.5 T).

View Journal Article

Cite

Export

Save

Research Organization:: Auburn Univ., AL (United States)

Sponsoring Organization:: USDOE Office of Science (SC), Fusion Energy Sciences (FES)

Contributing Organization:: W7-X Team

Grant/Contract Number:: SC0014529

OSTI ID:: 1825331

Alternate ID(s):: OSTI ID: 1823657; OSTI ID: 1979388

Journal Information:: Nuclear Fusion, Journal Name: Nuclear Fusion Vol. 61 Journal Issue: 10; ISSN 0029-5515

Publisher:: IOP PublishingCopyright Statement

Country of Publication:: IAEA

Language:: English

References (26)

Measurement of the edge ion temperature in W7-X with island divertor by a retarding field analyzer probe Li, Y.; Henkel, M.; Liang, Y. Nuclear Fusion, Vol. 59, Issue 12 https://doi.org/10.1088/1741-4326/ab3a79	journal	September 2019
Time resolved coherence-imaging spectrometer on WEGA stellarator Chung, Jinil; König, Ralf; Howard, John Plasma Physics and Controlled Fusion, Vol. 47, Issue 6 https://doi.org/10.1088/0741-3335/47/6/012	journal	May 2005
Zeeman Spectroscopy as a Tool for Studying Atomic Processes in Edge Plasmas Hey, J. D.; Chu, C. C.; Mertens, Ph. Contributions to Plasma Physics, Vol. 42, Issue 6-7 https://doi.org/10.1002/1521-3986(200211)42:6/7<635::aid-ctpp635>3.0.co;2-m	journal	November 2002
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
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
Atomic collision processes with ions at the edge of magnetically confined fusion plasmas Hey, J. D.; Chu, C. C.; Mertens, Ph Journal of Physics B: Atomic, Molecular and Optical Physics, Vol. 37, Issue 12 https://doi.org/10.1088/0953-4075/37/12/010	journal	June 2004
Imaging charge exchange recombination spectroscopy on the TEXTOR tokamak Howard, J.; Jaspers, R.; Lischtschenko, O. Plasma Physics and Controlled Fusion, Vol. 52, Issue 12 https://doi.org/10.1088/0741-3335/52/12/125002	journal	November 2010
Methods for quantitative study of divertor heat loads on W7-X Gao, Y.; Jakubowski, Marcin W.; Drewelow, Peter Nuclear Fusion, Vol. 59, Issue 6 https://doi.org/10.1088/1741-4326/ab0f49	journal	April 2019
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
Direct measurements of counter-streaming flows in a low-shear stellarator magnetic island topology Perseo, V.; Effenberg, F.; Gradic, D. Nuclear Fusion, Vol. 59, Issue 12 https://doi.org/10.1088/1741-4326/ab4320	journal	September 2019
Density measurements using coherence imaging spectroscopy based on Stark broadening Lischtschenko, O.; Bystrov, K.; De Temmerman, G. Review of Scientific Instruments, Vol. 81, Issue 10 https://doi.org/10.1063/1.3490023	journal	October 2010
Collisional–radiative studies of carbon plasmas Colgan, J.; Fontes, C. J.; Abdallah, J. High Energy Density Physics, Vol. 2, Issue 3-4 https://doi.org/10.1016/j.hedp.2006.07.001	journal	October 2006
Coherence-imaging spectroscopy for 2D distribution of ion temperature and flow velocity in a laboratory magnetosphere Nakamura, K.; Nishiura, M.; Takahashi, N. Review of Scientific Instruments, Vol. 89, Issue 10 https://doi.org/10.1063/1.5037124	journal	October 2018
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
Service oriented architecture for scientific analysis at W7-X. An example of a field line tracer Bozhenkov, S. A.; Geiger, J.; Grahl, M. Fusion Engineering and Design, Vol. 88, Issue 11 https://doi.org/10.1016/j.fusengdes.2013.07.003	journal	November 2013
Oxygen ion impurity in the TEXTOR tokamak boundary plasma observed and analysed by Zeeman spectroscopy Hey, J. D.; Chu, C. C.; Brezinsek, S. Journal of Physics B: Atomic, Molecular and Optical Physics, Vol. 35, Issue 6 https://doi.org/10.1088/0953-4075/35/6/309	journal	March 2002
2D measurements of parallel counter-streaming flows in the W7-X scrape-off layer for attached and detached plasmas Perseo, V.; Winters, V.; Feng, Y. Nuclear Fusion, Vol. 61, Issue 11 https://doi.org/10.1088/1741-4326/ac277a	journal	October 2021
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
Coherence imaging for ion temperature and flow measurements in a low-temperature helicon plasma source Lester, R.; Zhai, Y.; Corr, C. Plasma Sources Science and Technology, Vol. 25, Issue 1 https://doi.org/10.1088/0963-0252/25/1/015025	journal	January 2016
Confirmation of the topology of the Wendelstein 7-X magnetic field to better than 1:100,000 Pedersen, T. Sunn; Otte, M.; Lazerson, S. Nature Communications, Vol. 7, Issue 1 https://doi.org/10.1038/ncomms13493	journal	November 2016
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
Stokes-Doppler coherence imaging for ITER boundary tomography Howard, J.; Kocan, M.; Lisgo, S. Review of Scientific Instruments, Vol. 87, Issue 11 https://doi.org/10.1063/1.4963712	journal	October 2016
2D measurements of plasma electron density using coherence imaging with a pixelated phase mask Allcock, J. S.; Silburn, S. A.; Sharples, R. M. Review of Scientific Instruments, Vol. 92, Issue 7 https://doi.org/10.1063/5.0050704	journal	July 2021
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
Understanding detachment of the W7-X island divertor Feng, Y.; Jakubowski, M.; König, R. Nuclear Fusion, Vol. 61, Issue 8 https://doi.org/10.1088/1741-4326/ac0772	journal	June 2021
Measurements of ion energies in the tokamak plasma boundary Kočan, M.; Gunn, J. P.; Carpentier-Chouchana, S. Journal of Nuclear Materials, Vol. 415, Issue 1 https://doi.org/10.1016/j.jnucmat.2010.08.036	journal	August 2011

Similar Records

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

Journal Article · Tue Jun 19 00:00:00 EDT 2018 · Plasma Physics and Controlled Fusion · OSTI ID:1825331

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

Coherence imaging spectroscopy at Wendelstein 7-X for impurity flow measurements

Journal Article · Thu Jan 02 00:00:00 EST 2020 · Review of Scientific Instruments · OSTI ID:1825331

Perseo, Valeria; Gradic, Dorothea; König, Ralf; +4 more

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

Journal Article · Thu Oct 07 00:00:00 EDT 2021 · Nuclear Fusion · OSTI ID:1825331

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

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
Physics
coherence imaging spectroscopy
SOL ion temperature
Wendelstein 7-X
Doppler line broadening
Zeeman effect

Title: 2D coherence imaging measurements of C 2+ ion temperatures in the divertor of Wendelstein 7-X

Citation Formats

References (26)

Similar Records

Related Subjects

Title: 2D coherence imaging measurements of C ²⁺ ion temperatures in the divertor of Wendelstein 7-X