Investigation of deuterium trapping and release in the JET divertor during the third ILW campaign using TDS

Jari Likonen (Corresponding Author), Kalle Heinola, Andree De Backer, Aleksandra Baron-Wiechec, Norberto Catarino, Ionut Jepu, C.F. Ayres, Paul Coad, Guy Matthews, Anna Widdowson

Research output: Contribution to journalArticleScientificpeer-review

2 Citations (Scopus)

Abstract

Selected set of samples from JET ITER-Like Wall (JET-ILW) divertor tiles exposed in 2015–2016 has been analysed using Thermal Desorption Spectrometry (TDS). The deuterium (D) amounts obtained with TDS were compared with Nuclear Reaction Analysis (NRA). The highest amount of D was found on the top part of inner divertor which has regions with the thickest deposited layers as for divertor tiles removed in 2014. This area resides deep in the scrape-off layer and plasma configurations for the second (ILW-2, 2013–2014) and the third (ILW-3, 2015–2016) JET-ILW campaigns were similar. Agreement between TDS and NRA is good on the apron of Tile 1 and on the upper vertical region whereas on the lower vertical region of Tile 1 the NRA results are clearly smaller than the TDS results. Inner divertor Tile 3 has somewhat less D than Tiles 0 and 1, and the D amount decreases towards the lower part of the tile. The D retention at the divertor inner and outer corner regions is not symmetric as there is more D retention poloidally at the inner than at the outer divertor corner. In most cases the TDS spectra for the ILW-3 samples are different from the corresponding ILW-2 spectra because HD and D2 release occurs at higher temperatures than from the ILW-2 samples indicating that the low energy traps have been emptied during the plasma operations and that D is either in the energetically deep traps or located deeper in the sample.
Original languageEnglish
Pages (from-to)300-306
Number of pages6
JournalNuclear Materials and Energy
Volume19
DOIs
Publication statusPublished - 13 Mar 2019
MoE publication typeNot Eligible

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Thermal desorption
Deuterium
tiles
Tile
Spectrometry
deuterium
desorption
trapping
Nuclear reactions
spectroscopy
nuclear reactions
traps
Plasmas
configurations

Cite this

Likonen, Jari ; Heinola, Kalle ; De Backer, Andree ; Baron-Wiechec, Aleksandra ; Catarino, Norberto ; Jepu, Ionut ; Ayres, C.F. ; Coad, Paul ; Matthews, Guy ; Widdowson, Anna. / Investigation of deuterium trapping and release in the JET divertor during the third ILW campaign using TDS. In: Nuclear Materials and Energy. 2019 ; Vol. 19. pp. 300-306.
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title = "Investigation of deuterium trapping and release in the JET divertor during the third ILW campaign using TDS",
abstract = "Selected set of samples from JET ITER-Like Wall (JET-ILW) divertor tiles exposed in 2015–2016 has been analysed using Thermal Desorption Spectrometry (TDS). The deuterium (D) amounts obtained with TDS were compared with Nuclear Reaction Analysis (NRA). The highest amount of D was found on the top part of inner divertor which has regions with the thickest deposited layers as for divertor tiles removed in 2014. This area resides deep in the scrape-off layer and plasma configurations for the second (ILW-2, 2013–2014) and the third (ILW-3, 2015–2016) JET-ILW campaigns were similar. Agreement between TDS and NRA is good on the apron of Tile 1 and on the upper vertical region whereas on the lower vertical region of Tile 1 the NRA results are clearly smaller than the TDS results. Inner divertor Tile 3 has somewhat less D than Tiles 0 and 1, and the D amount decreases towards the lower part of the tile. The D retention at the divertor inner and outer corner regions is not symmetric as there is more D retention poloidally at the inner than at the outer divertor corner. In most cases the TDS spectra for the ILW-3 samples are different from the corresponding ILW-2 spectra because HD and D2 release occurs at higher temperatures than from the ILW-2 samples indicating that the low energy traps have been emptied during the plasma operations and that D is either in the energetically deep traps or located deeper in the sample.",
author = "Jari Likonen and Kalle Heinola and {De Backer}, Andree and Aleksandra Baron-Wiechec and Norberto Catarino and Ionut Jepu and C.F. Ayres and Paul Coad and Guy Matthews and Anna Widdowson",
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Likonen, J, Heinola, K, De Backer, A, Baron-Wiechec, A, Catarino, N, Jepu, I, Ayres, CF, Coad, P, Matthews, G & Widdowson, A 2019, 'Investigation of deuterium trapping and release in the JET divertor during the third ILW campaign using TDS', Nuclear Materials and Energy, vol. 19, pp. 300-306. https://doi.org/10.1016/j.nme.2019.03.012

Investigation of deuterium trapping and release in the JET divertor during the third ILW campaign using TDS. / Likonen, Jari (Corresponding Author); Heinola, Kalle; De Backer, Andree; Baron-Wiechec, Aleksandra; Catarino, Norberto; Jepu, Ionut; Ayres, C.F.; Coad, Paul; Matthews, Guy; Widdowson, Anna.

In: Nuclear Materials and Energy, Vol. 19, 13.03.2019, p. 300-306.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Investigation of deuterium trapping and release in the JET divertor during the third ILW campaign using TDS

AU - Likonen, Jari

AU - Heinola, Kalle

AU - De Backer, Andree

AU - Baron-Wiechec, Aleksandra

AU - Catarino, Norberto

AU - Jepu, Ionut

AU - Ayres, C.F.

AU - Coad, Paul

AU - Matthews, Guy

AU - Widdowson, Anna

PY - 2019/3/13

Y1 - 2019/3/13

N2 - Selected set of samples from JET ITER-Like Wall (JET-ILW) divertor tiles exposed in 2015–2016 has been analysed using Thermal Desorption Spectrometry (TDS). The deuterium (D) amounts obtained with TDS were compared with Nuclear Reaction Analysis (NRA). The highest amount of D was found on the top part of inner divertor which has regions with the thickest deposited layers as for divertor tiles removed in 2014. This area resides deep in the scrape-off layer and plasma configurations for the second (ILW-2, 2013–2014) and the third (ILW-3, 2015–2016) JET-ILW campaigns were similar. Agreement between TDS and NRA is good on the apron of Tile 1 and on the upper vertical region whereas on the lower vertical region of Tile 1 the NRA results are clearly smaller than the TDS results. Inner divertor Tile 3 has somewhat less D than Tiles 0 and 1, and the D amount decreases towards the lower part of the tile. The D retention at the divertor inner and outer corner regions is not symmetric as there is more D retention poloidally at the inner than at the outer divertor corner. In most cases the TDS spectra for the ILW-3 samples are different from the corresponding ILW-2 spectra because HD and D2 release occurs at higher temperatures than from the ILW-2 samples indicating that the low energy traps have been emptied during the plasma operations and that D is either in the energetically deep traps or located deeper in the sample.

AB - Selected set of samples from JET ITER-Like Wall (JET-ILW) divertor tiles exposed in 2015–2016 has been analysed using Thermal Desorption Spectrometry (TDS). The deuterium (D) amounts obtained with TDS were compared with Nuclear Reaction Analysis (NRA). The highest amount of D was found on the top part of inner divertor which has regions with the thickest deposited layers as for divertor tiles removed in 2014. This area resides deep in the scrape-off layer and plasma configurations for the second (ILW-2, 2013–2014) and the third (ILW-3, 2015–2016) JET-ILW campaigns were similar. Agreement between TDS and NRA is good on the apron of Tile 1 and on the upper vertical region whereas on the lower vertical region of Tile 1 the NRA results are clearly smaller than the TDS results. Inner divertor Tile 3 has somewhat less D than Tiles 0 and 1, and the D amount decreases towards the lower part of the tile. The D retention at the divertor inner and outer corner regions is not symmetric as there is more D retention poloidally at the inner than at the outer divertor corner. In most cases the TDS spectra for the ILW-3 samples are different from the corresponding ILW-2 spectra because HD and D2 release occurs at higher temperatures than from the ILW-2 samples indicating that the low energy traps have been emptied during the plasma operations and that D is either in the energetically deep traps or located deeper in the sample.

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U2 - 10.1016/j.nme.2019.03.012

DO - 10.1016/j.nme.2019.03.012

M3 - Article

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