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

Paris, P.; Jõgi, Indrek; Piip, K.; Passoni, M.; Dellasega, David; Grigore, E.; Arnoldbik, W.M.; Meiden, H. van der

doi:10.1016/j.fusengdes.2021.112403

Cited by 15 publications

(13 citation statements)

References 38 publications

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“…A simple but still accurate semi-empirical calibration model, similar to the MIEY approximation in GDOES, does not exist in LIBS, because of the much more complex physics involved in the atomization (ablation) and excitation processes. There have been attempts to interpret the LIBS spectra on the basis of the concepts of fundamental plasma physics, using plasma parameters such as excitation temperatures (calibration-free (CF) LIBS [59][60][61]). Their analytical outcome, however, has so far been rather semi-quantitative, with few exceptions, such as the analysis of glass [62].…”

Section: Laser-induced Breakdown Spectrometry (Libs)mentioning

confidence: 99%

Analysis of Hydrogen in Inorganic Materials and Coatings: A Critical Review

Weiss

2021

Hydrogen

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The currently used bulk analysis and depth profiling methods for hydrogen in inorganic materials and inorganic coatings are reviewed. Bulk analysis of hydrogen is based on fusion of macroscopic samples in an inert gas and the detection of the thereby released gaseous H2 using inert gas fusion (IGF) and thermal desorption spectroscopy (TDS). They offer excellent accuracy and sensitivity. Depth profiling methods involve glow discharge optical emission spectroscopy and mass spectrometry (GDOES and GDMS), laser-induced breakdown spectroscopy (LIBS), secondary ion mass spectrometry (SIMS), nuclear reaction analysis (NRA), and elastic recoil detection analysis (ERDA). The principles of all these methods are explained in terms of the methodology, calibration procedures, analytical performance, and major application areas. The synergies and the complementarity of various methods of hydrogen analysis are described. The existing literature about these methods is critically evaluated, and major papers concerning each method are listed.

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Section: Laser-induced Breakdown Spectrometry (Libs)mentioning

confidence: 99%

Analysis of Hydrogen in Inorganic Materials and Coatings: A Critical Review

Weiss

2021

Hydrogen

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“…7 and 8) [37,38]. Similar outgassing experiments were carried out with SP-LIBS (at 1 mbar Ar pressure) in Magnum-PSI [39]. Two hours after (D) plasma switch-off LIBS measurements could be performed.…”

Section: System Sensitivitymentioning

confidence: 99%

“…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%

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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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“…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%