CF-LIBS quantification and depth profile analysis of Be coating mixed layers

Dwivedi, Vishal; Marín-Roldán, A.; Karhunen, J.; Paris, P.; Jõgi, Indrek; Poroşnicu, C.; Lungu, C. P.; Meiden, H. van der; Hakola, A.; Veis, P.

doi:10.1016/j.nme.2021.100990

Cited by 13 publications

(17 citation statements)

References 28 publications

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“…The W-based coatings were used, with D or He included during coating production or loaded during plasma exposure in linear plasma generators. In the Be-mixed coatings [15] D was included during production.…”

Section: Libs Test Samples and Their Characterizationmentioning

confidence: 99%

“…The necessity of a precise Te determination is presented in Fig. 9, showing the dependence of the calculated elemental composition in a Be-D sample as a function of Te: 0.1 eV uncertainty of Te causes a difference of 27.5% in the calculated D content [15]. Fig.…”

Section: Determination Of Te In Plasma Plumementioning

confidence: 99%

“…Fig. 9: Variation of CF-LIBS results: calculated relative elemental composition (at.%), for varying Te [15]. The uncertainty in the Te evaluation leads to an error in the concentration calculation, which shows the importance of correct Te determination.…”

Section: Determination Of Te In Plasma Plumementioning

confidence: 99%

“…6. The accuracy in quantitative composition determination is strongly affected by the accuracy in Te [15] in the LIBS plasma plume and requires careful setting of detection delays. 7.…”

Section: Ps-libsmentioning

confidence: 99%

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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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Section: Libs Test Samples and Their Characterizationmentioning

confidence: 99%

Section: Determination Of Te In Plasma Plumementioning

confidence: 99%

Section: Determination Of Te In Plasma Plumementioning

confidence: 99%

“…6. The accuracy in quantitative composition determination is strongly affected by the accuracy in Te [15] in the LIBS plasma plume and requires careful setting of detection delays. 7.…”

Section: Ps-libsmentioning

confidence: 99%

See 2 more Smart Citations

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

Self Cite

View full text Add to dashboard Cite

show abstract

“…14 Currently, most of the reports on CF-LIBS were performed in open air or reduced pressure at tenths of mbar to 1 bar. 15–18 This type of environment is conducive to obtaining strong LIBS signals. The ambient gas provides collisional excitation to all plume species, and hence, it enhances the signal intensity from all emission lines.…”

Section: Introductionmentioning

confidence: 99%