Depth profile CF LIBS analysis of the wall deposited layer in the COMPASS tokamak after LiSn testing campaign

0581954 - ÚFP 2024 RIV NL eng J - Journal Article
Shetty, N. - Veis, M. - Atikukke, S. - Bartoň, Petr - Jeřáb, Martin - Dejarnac, Renaud - Veis, P.
Depth profile CF LIBS analysis of the wall deposited layer in the COMPASS tokamak after LiSn testing campaign.
Nuclear Materials and Energy. Roč. 37, December (2023), č. článku 101547. E-ISSN 2352-1791
Institutional support: RVO:61389021
Keywords : Calibration free (CF) approach * Deposited layer analysis * Depth profile * Fusion plasma wall interaction * Laser-induced breakdown spectroscopy (LIBS) * Li and Sn migration * Liquid metal divertor (LMD)
OECD category: Fluids and plasma physics (including surface physics)
Impact factor: 2.6, year: 2022
Method of publishing: Open access
https://www.sciencedirect.com/science/article/pii/S2352179123001862?via%3Dihub

Plasma-facing materials in tokamak nuclear reactors are subject to intense heat and radiation. The design of liquid metal (LM) divertor walls has several advantages over the solid counterparts. It is important to understand the migration and re-deposition of LMs such as lithium (Li), lead (Pb) or even tin (Sn). This work presents CF LIBS depth profile analysis of the deposited layer on Ni–Cr based screws situated at different places in the COMPASS tokamak vessel during the Capillary Porous System (CPS) LM (LiSn) divertor testing campaign. The experiment was carried out at low Ar pressure (100 mbar) using ns Nd:YAG laser operating at 532 nm. The spectra were recorded using echelle spectrometer (M5000, Andor Tech.) equipped with an iCCD camera (iStar DH743, Andor Tech.). The quantification was based on observed C I, B I, Li I and (weak) Sn I lines, in addition to trace elements (Ca, Na, K) and main matrix elements (Cr, Ni, Fe). The evaluation of electron temperature and density was based on Cr I-II, Ni-II and Fe I-II lines. The LM based content is estimated to be Li (0.3-0.81 at.%) and Sn (0.1-0.23 at.%) with Li/Sn at.% ratio ranging from 3 to 3.5 (wt.% ratio of 0.17-0.20). In practise, the limit of detection of Sn by CF LIBS for this type of Cr-Ni-Fe based matrix is observed to be ∼0.1 at.%.
Permanent Link: https://hdl.handle.net/11104/0350093