LIBS study of ITER relevant tungsten–oxygen coatings exposed to deuterium plasma in Magnum-PSI

Jõgi, Indrek; Paris, P.; Laan, M.; Kozlova, J.; Mändar, Hugo; Passoni, M.; Dellasega, David; Hakola, A.; Meiden, H.J. van der

doi:10.1016/j.jnucmat.2020.152660

Cited by 15 publications

(9 citation statements)

References 50 publications

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“…Both ID and IH were highest during the first shot. In the case of c-W coating, the ID of first shot was higher in the region of coating exposed to the central zone of plasma beam while in case of p-W-O coating there was no clear correlation with the different regions on the coating similarly with our earlier study [28].…”

Section: And H Intensities and Elemental Depth Profiles By In-situ Libssupporting

confidence: 79%

“…As the plasma beam was not deposited at the geometrical center of the samples, the faint contrast of the plasma treated region complicates the comparison between results obtained by NRA and LIBS. The thick W coating had small specks attributable to flaking off from most of the surface except for the region corresponding to the central part of plasma beam [28]. The main observations for in-situ LIBS on thin c-W and p-W-O coatings are the following:…”

Section: Resultsmentioning

confidence: 98%

“…Our previous ex-situ LIBS study [28] of D retention in nanostructured compact and porous W-O coatings loaded by Magnum-PSI plasma demonstrated the LIBS ability to obtain qualitative correspondence with D retention in the coatings. However, a disadvantage was that this study was made several months after D loading.…”

Section: Introductionmentioning

confidence: 93%

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In-situ LIBS and NRA deuterium retention study in porous W-O and compact W coatings loaded by Magnum-PSI

Paris

Jõgi

Piip

et al. 2021

Fusion Engineering and Design

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Section: And H Intensities and Elemental Depth Profiles By In-situ Libssupporting

confidence: 79%

Section: Resultsmentioning

confidence: 98%

See 1 more Smart Citation

In-situ LIBS and NRA deuterium retention study in porous W-O and compact W coatings loaded by Magnum-PSI

Paris

Jõgi

Piip

et al. 2021

Fusion Engineering and Design

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“…Deuterium retention in compact, porous W-O coatings was successfully assessed using LIBS. 166 The coatings were exposed to a D plasma, with strong signals measured in the laser shot corresponding to the surface layer, reducing to noise levels deeper in the coating, with higher signals in the central region. The results were supported by SIMS measurement of the lateral surface, while SEM and XRD data also supported the measured change in surface morphology.…”

Section: Nuclear Materialsmentioning

confidence: 99%

Atomic spectrometry update: review of advances in the analysis of metals, chemicals and materials

Carter

Clough

Fisher

et al. 2021

J. Anal. At. Spectrom.

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“…Ablation rate /laser fluence 60-160 nm/pulse (W) 7 J/cm 2 [54] 400-800 nm/pulse (porous W-Al) 7 J/cm 2 [54] 250-500 nm/pulse (columnar W-O) 15-20 J/cm 2 [39,55] 210 nm/pulse (W-N-D) 66 J/cm 2 [28] Operational press. range H isotope distinguishability 1 bar N2 or air [28] Quality: high till 100 mbar N2 [23] At 1 bar Ar [22] Distinguishable at long delays with low S/N ratio Highest operational press.…”

Section: Table 1 Sp-libsmentioning

confidence: 99%

Monitoring of tritium and impurities in the first wall of fusion devices using a LIBS based diagnostic

Meiden¹,

Almaviva²,

Butikova³

et al. 2021

Nucl. Fusion

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Laser-induced breakdown spectroscopy (LIBS) is one of the most promising methods for quantitative in-situ determination of fuel retention in plasma-facing components (PFCs) of magnetically confined fusion devices like ITER and JET. In this article, the current state of understanding in LIBS development for fusion applications will be presented, based on a complete review of existing results and complemented with newly obtained data. The work has been performed as part of a research programme, set up in the EUROfusion Consortium, to address the main requirements for ITER: (a) quantification of fuel from relevant surfaces with high sensitivity, (b) the technical demonstration to perform LIBS with a remote handling system and (c) accurate detection of fuel at ambient pressures relevant for ITER. For the first goal, the elemental composition of ITER-like deposits and proxies to them, including deuterium (D) or helium (He) containing W–Be, W, W–Al and Be–O–C coatings, was successfully determined with a typical depth resolution ranging from 50 up to 250 nm per laser pulse. Deuterium was used as a substitute for tritium (T) and in the LIBS experiments deuterium surface densities below 1016 D/cm2 could be measured with an accuracy of ∼30%, confirming the required high sensitivity for fuel-retention investigations. The performance of different LIBS configurations was explored, comprising LIBS systems based on single pulse (pulse durations: ps–ns) and double pulse lasers with different pulse durations. For the second goal, a remote handling application was demonstrated inside the Frascati-Tokamak-Upgrade (FTU), where a compact, remotely controlled LIBS system was mounted on a multipurpose deployer providing an in-vessel retention monitor system. During a shutdown phase, LIBS was performed at atmospheric pressure, for measuring the composition and fuel content of different area of the stainless-steel FTU first wall, and the titanium zirconium molybdenum alloy tiles of the toroidal limiter. These achievements underline the capability of a LIBS-based retention monitor, which complies with the requirements for JET and ITER operating in DT with a beryllium wall and a tungsten divertor. Concerning the capabilities of LIBS at pressure conditions relevant for ITER, quantitative determination of the composition of PFC materials at ambient pressures up to 100 mbar of N2, the D content could be determined with an accuracy of 25%, while for atmospheric pressure conditions, an accuracy of about 50% was found when using single-pulse lasers. To improve the LIBS performance in atmospheric pressure conditions, a novel approach is proposed for quantitative determination of the retained T and the D/T ratio. This scenario is based on measuring the LIBS plume emission at two different time delays after each laser pulse. On virtue of application of a double pulse LIBS system, for LIBS application at N2 atmospheric pressure the distinguishability of the spectra from H isotopes could be significantly improved, but further systematic research is required.

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LIBS study of ITER relevant tungsten–oxygen coatings exposed to deuterium plasma in Magnum-PSI

Cited by 15 publications

References 50 publications

In-situ LIBS and NRA deuterium retention study in porous W-O and compact W coatings loaded by Magnum-PSI

In-situ LIBS and NRA deuterium retention study in porous W-O and compact W coatings loaded by Magnum-PSI

Atomic spectrometry update: review of advances in the analysis of metals, chemicals and materials

Monitoring of tritium and impurities in the first wall of fusion devices using a LIBS based diagnostic

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