Plasma–surface interaction in the stellarator W7-X: conclusions drawn from operation with graphite plasma-facing components

BrezƖnsek, S.; Dhard, C. P.; Jakubowski, M.; König, R.; Masuzaki, S.; Mayer, M.; Naujoks, D.; Romazanov, J.; Schmid, K.; Schmitz, O.; Zhao, D.; Balden, M.; Brakel, R.; Butterschoen, B.; Dittmar, T.; Drews, P.; Effenberg, F.; Elgeti, S.; Ford, O.; Fortuna-Zalesna, E.; Fuchert, G.; Gao, Y.; Goriaev, A.; Hakola, A.; Kremeyer, T.; Krychowiak, M.; Liang, Y.; Linsmeier, Ch; Lunsford, R.; Motojima, G.; Neu, R.; Neubauer, O.; Oelmann, J.; Petersson, P.; Rasinski, M.; Rubel, M.; Sereda, S.; Sergienko, G.; Sunn Pedersen, T.; Vuoriheimo, T.; Wang, E.; Wauters, T.; Winters, V.; Zhao, M.; Yi, R.; the W7-X Team,

doi:10.1088/1741-4326/ac3508

Plasma–surface interaction in the stellarator W7-X: conclusions drawn from operation with graphite plasma-facing components

Journal Article · Thu Dec 02 00:00:00 EST 2021 · Nuclear Fusion

DOI:https://doi.org/10.1088/1741-4326/ac3508· OSTI ID:1828773

; Dhard, C. P.; ; ; ; ; ; ; Schmid, K.; ; ; ; Brakel, R.; ; ; ; ; Elgeti, S.; ; more »

W7-X completed its plasma operation in hydrogen with island divertor and inertially cooled test divertor unit (TDU) made of graphite. A substantial set of plasma-facing components (PFCs), including in particular marker target elements, were extracted from the W7-X vessel and analysed post-mortem. The analysis provided key information about underlying plasma–surface interactions (PSI) processes, namely erosion, transport, and deposition as well as fuel retention in the graphite components. The net carbon (C) erosion and deposition distribution on the horizontal target (HT) and vertical target (VT) plates were quantified and related to the plasma time in standard divertor configuration with edge transform ι = 5/5, the dominant magnetic configuration of the two operational phases (OP) with TDU. The operation resulted in integrated high net C erosion rate of 2.8 mg s^-1 in OP1.2B over 4809 plasma seconds. Boronisations reduced the net erosion on the HT by about a factor 5.4 with respect to OP1.2A owing to the suppression of oxygen (O). In the case of the VT, high peak net C erosion of 11μm at the strike line was measured during OP1.2B which converts to 2.5 nm s^-1 or 1.4 mg s^-1 when related to the exposed area of the target plate and the operational time in standard divertor configuration. PSI modelling with ERO2.0 and WallDYN-3D is applied in an interpretative manner and reproduces the net C erosion and deposition pattern at the target plates determined by different post-mortem analysis techniques. This includes also the ¹³C tracer deposition from the last experiment of OP1.2B with local ¹³CH₄ injection through a magnetic island in one half module. The experimental findings are used to predict the C erosion, transport, and deposition in the next campaigns aiming in long-pulse operation up to 1800 s and utilising the actively cooled carbon-fibre composite (CFC) divertor currently being installed. The CFC divertor has the same geometrical design as the TDU and extrapolation depends mainly on the applied plasma boundary. Extrapolation from campaign averaged information obtained in OP1.2B reveals a net erosion of 7.6 g per 1800 s for a typical W7-X attached divertor plasma in hydrogen.

View Accepted Manuscript (DOE)

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

Sponsoring Organization:: EUROfusion Consortium; German Research Foundation (DFG); USDOE

Contributing Organization:: W-7X Team

Grant/Contract Number:: AC02-09CH11466; SC0014210

OSTI ID:: 1828773

Journal Information:: Nuclear Fusion, Journal Name: Nuclear Fusion Journal Issue: 1 Vol. 62; ISSN 0029-5515

Publisher:: IOP ScienceCopyright Statement

Country of Publication:: United States

Language:: English

References (60)

Hydrocarbon Collision Cross Sections for Magnetic Fusion: The Methane, Ethane and Propane Families Reiter, D.; Janev, R. K. Contributions to Plasma Physics, Vol. 50, Issue 10 https://doi.org/10.1002/ctpp.201000090	journal	November 2010
Recent Improvements in the EMC3-Eirene Code: Recent Improvements in the EMC3-Eirene Code Feng, Y.; Frerichs, H.; Kobayashi, M. Contributions to Plasma Physics, Vol. 54, Issue 4-6 https://doi.org/10.1002/ctpp.201410092	journal	June 2014
3-Dimensional analysis of layer structured samples with high depth resolution using picosecond laser-induced breakdown spectroscopy Yi, Rongxing; Zhao, Dongye; Oelmann, Jannis Applied Surface Science, Vol. 532 https://doi.org/10.1016/j.apsusc.2020.147185	journal	December 2020
Industrial scale 10μmW coating of CFC tiles for ITER-like Wall Project at JET Ruset, C.; Grigore, E.; Munteanu, I. Fusion Engineering and Design, Vol. 84, Issue 7-11 https://doi.org/10.1016/j.fusengdes.2008.11.053	journal	June 2009
Design and technological solutions for the plasma facing components of WENDELSTEIN 7-X Boscary, J.; Stadler, R.; Peacock, A. Fusion Engineering and Design, Vol. 86, Issue 6-8 https://doi.org/10.1016/j.fusengdes.2010.11.020	journal	October 2011
Upgrades of edge, divertor and scrape-off layer diagnostics of W7‐X for OP1.2 Hathiramani, D.; Ali, A.; Anda, G. Fusion Engineering and Design, Vol. 136 https://doi.org/10.1016/j.fusengdes.2018.02.013	journal	November 2018
Erosion and deposition investigations on Wendelstein 7-X first wall components for the first operation phase in divertor configuration Dhard, Chandra Prakash; Mayer, Matej; Brezinsek, Sebastijan Fusion Engineering and Design, Vol. 146 https://doi.org/10.1016/j.fusengdes.2018.12.031	journal	September 2019
A horizontal powder injector for W7-X Nagy, Alexander; Bortolon, A.; Gates, D. Fusion Engineering and Design, Vol. 146 https://doi.org/10.1016/j.fusengdes.2018.12.099	journal	September 2019
Flux dependence of carbon erosion and implication for ITER Roth, J.; Kirschner, A.; Bohmeyer, W. Journal of Nuclear Materials, Vol. 337-339 https://doi.org/10.1016/j.jnucmat.2004.10.115	journal	March 2005
Hydrocarbon injection for quantification of chemical erosion yields in tokamaks Brezinsek, S.; Pospieszczyk, A.; Borodin, D. Journal of Nuclear Materials, Vol. 363-365 https://doi.org/10.1016/j.jnucmat.2007.01.190	journal	June 2007
Fuel retention in tokamaks Loarer, T. Journal of Nuclear Materials, Vol. 390-391 https://doi.org/10.1016/j.jnucmat.2009.01.039	journal	June 2009
The impact of divertor detachment on carbon sources in JET L-mode discharges Brezinsek, S.; Meigs, A. G.; Jachmich, S. Journal of Nuclear Materials, Vol. 390-391 https://doi.org/10.1016/j.jnucmat.2009.01.100	journal	June 2009
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
Overview on plasma operation with a full tungsten wall in ASDEX Upgrade Neu, R.; Kallenbach, A.; Balden, M. Journal of Nuclear Materials, Vol. 438 https://doi.org/10.1016/j.jnucmat.2013.01.006	journal	July 2013
Studies of impurity migration in TEXTOR by local tracer injection Kirschner, A.; Wienhold, P.; Borodin, D. Journal of Nuclear Materials, Vol. 438 https://doi.org/10.1016/j.jnucmat.2013.01.153	journal	July 2013
Plasma-surface interaction in the Be/W environment: Conclusions drawn from the JET-ILW for ITER Brezinsek, S. Journal of Nuclear Materials, Vol. 463 https://doi.org/10.1016/j.jnucmat.2014.12.007	journal	August 2015
Plasma wall interaction in long-pulse helium discharge in LHD – Microscopic modification of the wall surface and its impact on particle balance and impurity generation Tokitani, M.; Kasahara, H.; Masuzaki, S. Journal of Nuclear Materials, Vol. 463 https://doi.org/10.1016/j.jnucmat.2014.12.062	journal	August 2015
Wall conditioning throughout the first carbon divertor campaign on Wendelstein 7-X Wauters, Tom; Goriaev, Andrei; Alonso, Arturo Nuclear Materials and Energy, Vol. 17 https://doi.org/10.1016/j.nme.2018.11.004	journal	December 2018
3D global impurity transport modeling with WallDYN and EMC3-Eirene Schmid, K.; Lunt, T. Nuclear Materials and Energy, Vol. 17 https://doi.org/10.1016/j.nme.2018.11.005	journal	December 2018
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
Beryllium global erosion and deposition at JET-ILW simulated with ERO2.0 Romazanov, J.; Brezinsek, S.; Borodin, D. Nuclear Materials and Energy, Vol. 18 https://doi.org/10.1016/j.nme.2019.01.015	journal	January 2019
Surface roughness effect on Mo physical sputtering and re-deposition in the linear plasma device PSI-2 predicted by ERO2.0 Eksaeva, A.; Borodin, D.; Romazanov, J. Nuclear Materials and Energy, Vol. 19 https://doi.org/10.1016/j.nme.2019.02.006	journal	May 2019
Integrated modelling: Coupling of surface evolution and plasma-impurity transport Schmid, K.; Effenberg, F.; Dinklage, A. Nuclear Materials and Energy, Vol. 25 https://doi.org/10.1016/j.nme.2020.100821	journal	December 2020
Hydrogen content in divertor baffle tiles in Wendelstein 7-X Oelmann, Jannis; Wüst, Erik; Brezinsek, Sebastijan Nuclear Materials and Energy, Vol. 26 https://doi.org/10.1016/j.nme.2021.100943	journal	March 2021
Time resolved observation of the erosion of boron containing protective coatings on wall elements of TEXTOR-94 by means of colorimetry Wienhold, P. Journal of Nuclear Materials, Vol. 241-243, Issue 1 https://doi.org/10.1016/s0022-3115(96)00610-1	journal	February 1997
Ion beam analysis of rough thin films Mayer, M. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, Vol. 194, Issue 2 https://doi.org/10.1016/s0168-583x(02)00689-4	journal	August 2002
An ultraviolet-visible-near infrared overview spectroscopy for divertor plasma diagnosis on Wendelstein 7-X Wei, Y.; Wang, E.; Liang, Y. AIP Advances, Vol. 8, Issue 8 https://doi.org/10.1063/1.5033371	journal	August 2018
Infrared imaging systems for wall protection in the W7-X stellarator (invited) Jakubowski, Marcin; Drewelow, Peter; Fellinger, Joris Review of Scientific Instruments, Vol. 89, Issue 10 https://doi.org/10.1063/1.5038634	journal	October 2018
The Langmuir probe system in the Wendelstein 7-X test divertor Rudischhauser, L.; Endler, M.; Höfel, U. Review of Scientific Instruments, Vol. 91, Issue 6 https://doi.org/10.1063/1.5143013	journal	June 2020
Analytic description of the chemical erosion of graphite by hydrogen ions Roth, J.; Garcia-Rosales, C. Nuclear Fusion, Vol. 36, Issue 12 https://doi.org/10.1088/0029-5515/36/12/i05	journal	December 1996
Deuterium inventory in Tore Supra: reconciling particle balance and post-mortem analysis Tsitrone, E.; Brosset, C.; Pégourié, B. Nuclear Fusion, Vol. 49, Issue 7 https://doi.org/10.1088/0029-5515/49/7/075011	journal	June 2009
WEST Physics Basis Bourdelle, C.; Artaud, J. F.; Basiuk, V. Nuclear Fusion, Vol. 55, Issue 6 https://doi.org/10.1088/0029-5515/55/6/063017	journal	May 2015
Wall conditioning in fusion devices and its influence on plasma performance Winter, J. Plasma Physics and Controlled Fusion, Vol. 38, Issue 9 https://doi.org/10.1088/0741-3335/38/9/001	journal	September 1996
First results from divertor operation in Wendelstein 7-X Pedersen, Thomas Sunn; König, Ralf; Krychowiak, Maciej Plasma Physics and Controlled Fusion, Vol. 61, Issue 1 https://doi.org/10.1088/1361-6587/aaec25	journal	November 2018
Drift effects on W7-X divertor heat and particle fluxes Hammond, K. C.; Gao, Y.; Jakubowski, M. Plasma Physics and Controlled Fusion, Vol. 61, Issue 12 https://doi.org/10.1088/1361-6587/ab4825	journal	October 2019
EMC3-EIRENE simulation of first wall recycling fluxes in W7-X with relation to H-alpha measurements Winters, V. R.; Reimold, F.; König, R. Plasma Physics and Controlled Fusion, Vol. 63, Issue 4 https://doi.org/10.1088/1361-6587/abe39c	journal	March 2021
Ex situ analysis of W7-X divertor plasma-facing components by picosecond laser diagnostics Zhao, D.; Yi, R.; Oelmann, J. Physica Scripta, Vol. T171 https://doi.org/10.1088/1402-4896/ab3ee1	journal	January 2020
Temperature dependence of deuterium retention at displacement damage in tungsten Wampler, W. R. Physica Scripta, Vol. T171 https://doi.org/10.1088/1402-4896/ab4312	journal	January 2020
Inspection of W 7-X plasma-facing components after the operation phase OP1.2b: observations and first assessments Dhard, C. P.; Äkäslompolo, S.; Balden, M. Physica Scripta, Vol. T171 https://doi.org/10.1088/1402-4896/ab4b3f	journal	January 2020
Material erosion and deposition on the divertor of W7-X Mayer, M.; Balden, M.; Brezinsek, S. Physica Scripta, Vol. T171 https://doi.org/10.1088/1402-4896/ab4b8c	journal	January 2020
In-vessel colorimetry of Wendelstein 7-X first wall components: variation of layer deposition distribution in OP1.2a and OP1.2b Motojima, G.; Masuzaki, S.; Dhard, C. P. Physica Scripta, Vol. T171 https://doi.org/10.1088/1402-4896/ab5618	journal	January 2020
Wall conditioning at the Wendelstein 7-X stellarator operating with a graphite divertor Goriaev, A.; Wauters, T.; Brakel, R. Physica Scripta, Vol. T171 https://doi.org/10.1088/1402-4896/ab60fa	journal	January 2020
Deposition of 13C tracer and impurity elements on the divertor of Wendelstein 7-X Vuoriheimo, Tomi; Hakola, Antti; Likonen, Jari Physica Scripta, Vol. 96, Issue 12 https://doi.org/10.1088/1402-4896/ac2381	journal	September 2021
Plasma-wall interaction studies in W7-X: main results from the recent divertor operations Dhard, C. P.; Brezinsek, S.; Mayer, M. Physica Scripta, Vol. 96, Issue 12 https://doi.org/10.1088/1402-4896/ac35c0	journal	November 2021
Double pulse laser-induced breakdown spectroscopy for the analysis of plasma-facing components Oelmann, J.; Wüst, E.; Sergienko, G. Physica Scripta, Vol. 96, Issue 12 https://doi.org/10.1088/1402-4896/ac379c	journal	November 2021
Erosion of tungsten marker layers in W7-X Mayer, M.; Balden, M.; Brezinsek, S. Physica Scripta, Vol. 96, Issue 12 https://doi.org/10.1088/1402-4896/ac3b68	journal	December 2021
Overview of first Wendelstein 7-X high-performance operation Klinger, T.; Andreeva, T.; Bozhenkov, S. Nuclear Fusion, Vol. 59, Issue 11 https://doi.org/10.1088/1741-4326/ab03a7	journal	June 2019
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
First divertor physics studies in Wendelstein 7-X Sunn Pedersen, T.; König, R.; Jakubowski, M. Nuclear Fusion, Vol. 59, Issue 9 https://doi.org/10.1088/1741-4326/ab280f	journal	July 2019
First demonstration of radiative power exhaust with impurity seeding in the island divertor at Wendelstein 7-X Effenberg, F.; Brezinsek, S.; Feng, Y. Nuclear Fusion, Vol. 59, Issue 10 https://doi.org/10.1088/1741-4326/ab32c4	journal	August 2019
Increasing the density in Wendelstein 7-X: benefits and limitations Fuchert, G.; Brunner, K. J.; Rahbarnia, K. Nuclear Fusion, Vol. 60, Issue 3 https://doi.org/10.1088/1741-4326/ab6d40	journal	February 2020
Large wetted areas of divertor power loads at Wendelstein 7-X Niemann, H.; Drewelow, P.; Jakubowski, M. W. Nuclear Fusion, Vol. 60, Issue 8 https://doi.org/10.1088/1741-4326/ab937a	journal	July 2020
Impact of boronizations on impurity sources and performance in Wendelstein 7-X Sereda, S.; Brezinsek, S.; Wang, E. Nuclear Fusion, Vol. 60, Issue 8 https://doi.org/10.1088/1741-4326/ab937b	journal	July 2020
Stable heat and particle flux detachment with efficient particle exhaust in the island divertor of Wendelstein 7-X Schmitz, Oliver; Feng, Yuhe; Jakubowski, Marcin Nuclear Fusion https://doi.org/10.1088/1741-4326/abb51e	journal	September 2020
Quantification of erosion pattern using picosecond-LIBS on a vertical divertor target element exposed in W7-X Zhao, D.; Yi, R.; Eksaeva, A. Nuclear Fusion, Vol. 61, Issue 1 https://doi.org/10.1088/1741-4326/abc408	journal	December 2020
Overview of the results from divertor experiments with attached and detached plasmas at Wendelstein 7-X and their implications for steady-state operation Jakubowski, M.; Endler, M.; Feng, Y. Nuclear Fusion, Vol. 61, Issue 10 https://doi.org/10.1088/1741-4326/ac1b68	journal	August 2021
Spectroscopic studies of fuel recycling and impurity behaviors in the divertor region of Wendelstein 7-X Wei, Yanling; Wang, Erhui; Liang, Yunfeng Plasma Science and Technology, Vol. 21, Issue 10 https://doi.org/10.1088/2058-6272/ab273b	journal	July 2019
Wall Conditioning on TEXTOR Philipps, V. Fusion Science and Technology, Vol. 47, Issue 2 https://doi.org/10.13182/fst05-a693	journal	February 2005
Actively Water-Cooled Plasma Facing Components of the Wendelstein 7-X Stellarator Boscary, J.; Peacock, A.; Stadler, R. Fusion Science and Technology, Vol. 64, Issue 2 https://doi.org/10.13182/fst12-499	journal	August 2013
JURECA: Modular supercomputer at Jülich Supercomputing Centre Krause, Dorian; Thörnig, Philipp Journal of large-scale research facilities JLSRF, Vol. 4 https://doi.org/10.17815/jlsrf-4-121-1	journal	January 2018

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