Overview of the second stage in the comprehensive mirrors test in JET

JET-EFDA collaborators

Research output: Contribution to journalArticleScientificpeer-review

14 Citations (Scopus)

Abstract

The first mirror test for ITER in JET with carbon walls has been completed. Thirty polycrystalline Mo mirrors including four coated with a 1 μm rhodium (Rh) film were exposed to plasma in the divertor region and in the main chamber. The mirrors were installed in eight cassettes of pan-pipe shape. The reflectivity of all mirrors exposed in the divertor has been degraded by 80–90% because of the formation of thick (>20 μm) flaking co-deposits on surfaces. Only small reflectivity losses (5–10%) occurred on mirrors located at the channel mouth of the cassettes from the main chamber wall. This is due to the in situ removal of deposited species by charge exchange neutrals. Deuterium, 12C and 9Be are the main isotopes detected on surfaces, but other isotopes (13C) are also found in some locations, thus indicating differences in the material migration. Rhodium coatings with an initial reflectivity that is 30% better than that of pure Mo survived the test without detachment, but their resultant reflectivity was the same as that of the exposed Mo surfaces.
Original languageEnglish
Article number014070
Number of pages6
JournalPhysica Scripta
Issue numberT145
DOIs
Publication statusPublished - 2011
MoE publication typeA1 Journal article-refereed
Event13th International Workshop on Plasma-Facing Materials and Components for Fusion Applications, PFMC-13 - Rosenheim, Germany
Duration: 9 May 201113 May 2011

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Reflectivity
Mirror
mirrors
reflectance
rhodium
isotopes
chambers
flaking
mouth
detachment
charge exchange
Coating
Migration
deuterium
Carbon
Plasma
deposits
Charge
coatings
carbon

Cite this

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title = "Overview of the second stage in the comprehensive mirrors test in JET",
abstract = "The first mirror test for ITER in JET with carbon walls has been completed. Thirty polycrystalline Mo mirrors including four coated with a 1 μm rhodium (Rh) film were exposed to plasma in the divertor region and in the main chamber. The mirrors were installed in eight cassettes of pan-pipe shape. The reflectivity of all mirrors exposed in the divertor has been degraded by 80–90{\%} because of the formation of thick (>20 μm) flaking co-deposits on surfaces. Only small reflectivity losses (5–10{\%}) occurred on mirrors located at the channel mouth of the cassettes from the main chamber wall. This is due to the in situ removal of deposited species by charge exchange neutrals. Deuterium, 12C and 9Be are the main isotopes detected on surfaces, but other isotopes (13C) are also found in some locations, thus indicating differences in the material migration. Rhodium coatings with an initial reflectivity that is 30{\%} better than that of pure Mo survived the test without detachment, but their resultant reflectivity was the same as that of the exposed Mo surfaces.",
author = "M. Rubel and D. Ivanova and J.P. Coad and {De Temmerman}, G. and Jari Likonen and L. Marot and A. Schmidt and A. Widdowson and {JET-EFDA collaborators}",
year = "2011",
doi = "10.1088/0031-8949/2011/T145/014070",
language = "English",
journal = "Physica Scripta",
issn = "0031-8949",
publisher = "Institute of Physics IOP",
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}

Overview of the second stage in the comprehensive mirrors test in JET. / JET-EFDA collaborators.

In: Physica Scripta, No. T145, 014070, 2011.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Overview of the second stage in the comprehensive mirrors test in JET

AU - Rubel, M.

AU - Ivanova, D.

AU - Coad, J.P.

AU - De Temmerman, G.

AU - Likonen, Jari

AU - Marot, L.

AU - Schmidt, A.

AU - Widdowson, A.

AU - JET-EFDA collaborators

PY - 2011

Y1 - 2011

N2 - The first mirror test for ITER in JET with carbon walls has been completed. Thirty polycrystalline Mo mirrors including four coated with a 1 μm rhodium (Rh) film were exposed to plasma in the divertor region and in the main chamber. The mirrors were installed in eight cassettes of pan-pipe shape. The reflectivity of all mirrors exposed in the divertor has been degraded by 80–90% because of the formation of thick (>20 μm) flaking co-deposits on surfaces. Only small reflectivity losses (5–10%) occurred on mirrors located at the channel mouth of the cassettes from the main chamber wall. This is due to the in situ removal of deposited species by charge exchange neutrals. Deuterium, 12C and 9Be are the main isotopes detected on surfaces, but other isotopes (13C) are also found in some locations, thus indicating differences in the material migration. Rhodium coatings with an initial reflectivity that is 30% better than that of pure Mo survived the test without detachment, but their resultant reflectivity was the same as that of the exposed Mo surfaces.

AB - The first mirror test for ITER in JET with carbon walls has been completed. Thirty polycrystalline Mo mirrors including four coated with a 1 μm rhodium (Rh) film were exposed to plasma in the divertor region and in the main chamber. The mirrors were installed in eight cassettes of pan-pipe shape. The reflectivity of all mirrors exposed in the divertor has been degraded by 80–90% because of the formation of thick (>20 μm) flaking co-deposits on surfaces. Only small reflectivity losses (5–10%) occurred on mirrors located at the channel mouth of the cassettes from the main chamber wall. This is due to the in situ removal of deposited species by charge exchange neutrals. Deuterium, 12C and 9Be are the main isotopes detected on surfaces, but other isotopes (13C) are also found in some locations, thus indicating differences in the material migration. Rhodium coatings with an initial reflectivity that is 30% better than that of pure Mo survived the test without detachment, but their resultant reflectivity was the same as that of the exposed Mo surfaces.

U2 - 10.1088/0031-8949/2011/T145/014070

DO - 10.1088/0031-8949/2011/T145/014070

M3 - Article

JO - Physica Scripta

JF - Physica Scripta

SN - 0031-8949

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