TY - JOUR
T1 - Quantification of H/D content in Be/W mixtures coatings by CF-LIBS
AU - Veis, P.
AU - Marín-Roldán, A.
AU - Dwivedi, V.
AU - Karhunen, J.
AU - Paris, P.
AU - Jõgi, I.
AU - Porosnicu, C.
AU - Lungu, C. P.
AU - Nemanic, V.
AU - Hakola, Antti
N1 - Funding Information:
This work was supported by the SRDA (APVV-16-0612), by the VEGA (1/0903/17). This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training program 2014–2018 and 2019–2020 under grant agreement No. 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission. Work performed under EUROfusion WP PFC.
Publisher Copyright:
© 2020
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2020/6/24
Y1 - 2020/6/24
N2 - 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.
AB - 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.
KW - BeW
KW - CF-LIBS
KW - fuel retention
KW - quantification
UR - http://www.scopus.com/inward/record.url?scp=85089276364&partnerID=8YFLogxK
U2 - 10.1088/1402-4896/ab7ebd
DO - 10.1088/1402-4896/ab7ebd
M3 - Article
AN - SCOPUS:85089276364
VL - 2020
JO - Physica Scripta
JF - Physica Scripta
SN - 0031-8949
IS - T171
M1 - 014073
T2 - 17th International Conference on Plasma-Facing Materials and Components for Fusion Applications, PFMC 2019
Y2 - 20 May 2019 through 24 May 2019
ER -