Quantification of H/D content in Be/W mixtures coatings by CF-LIBS

P. Veis (Corresponding Author), A. Marín-Roldán, V. Dwivedi, J. Karhunen, P. Paris, I. Jogi, C. Porosnicu, C. P. Lungu, V. Nemanic, A. Hakola

Research output: Contribution to journalArticle in a proceedings journalScientificpeer-review

1 Citation (Scopus)

Abstract

In ITER, a remote handling laser-induced breakdown spectroscopy (LIBS) system is considered to be able to observe regions where deposition of thick layers is expected to occur and assess the retention of fuel on wall structures. The H and D contents of surface layers on divertor and first-wall materials have been intensely studied by LIBS but mostly by depth profile analysis of D. As far as we know, quantitative analysis of H/D in BeW mixed layer by calibration free-LIBS (CF-LIBS) has not been performed. Thus, the aim of this work is the quantification of the relative concentrations of D and H in Be-based material samples by CF-LIBS. The samples used were Be/W(67:33) as mixed homogeneous coatings (2 μm) on Mo substrates. Laser ablation was performed using a 1064 nm laser with 5 ns pulses. In order to enhance the resolution to distinguish H, D and in future T from each other, two different pressures were used: high vacuum and 0.5 mbar of Ar. Suitable Be and W spectral lines (without interferences and self-absorption) have been selected for precise evaluation of the electron temperature, T e, of the plasma using the Boltzmann plots. The electron density, n e, was extracted from the Saha equation using the average electron temperatures obtained from the Stark broadening of the H α line. With these values, the D content of the samples has been calculated by CF LIBS as ∼4.7% ± 2.9%. These results are in a good agreement with thermal desorption spectroscopy measurements, which gives a 4-5 at% for the D content. In addition, the depth profile is similar to that recorded using secondary ion mass spectrometry.

Original languageEnglish
Article number014073
Number of pages7
JournalPhysica Scripta
Volume2020
Issue numberT171
DOIs
Publication statusPublished - 24 Jun 2020
MoE publication typeA4 Article in a conference publication
Event17th International Conference on Plasma-Facing Materials and Components for Fusion Applications, PFMC 2019 - Eindhoven, Netherlands
Duration: 20 May 201924 May 2019

Keywords

  • BeW
  • CF-LIBS
  • fuel retention
  • quantification

Fingerprint Dive into the research topics of 'Quantification of H/D content in Be/W mixtures coatings by CF-LIBS'. Together they form a unique fingerprint.

  • Cite this

    Veis, P., Marín-Roldán, A., Dwivedi, V., Karhunen, J., Paris, P., Jogi, I., Porosnicu, C., Lungu, C. P., Nemanic, V., & Hakola, A. (2020). Quantification of H/D content in Be/W mixtures coatings by CF-LIBS. Physica Scripta, 2020(T171), [014073]. https://doi.org/10.1088/1402-4896/ab7ebd