Ponente
Descripción
The development of fusion reactors beyond ITER requires the qualification of functional materials capable of operating under intense particle and neutron irradiation while maintaining their structural and functional properties. Lithium-based materials are attracting increasing interest for advanced fusion technologies, including liquid-metal plasma-facing concepts [1], due to their ability to mitigate power loads and reduce impurity contamination. However, their strong affinity for hydrogen isotopes may significantly affect fuel retention, material performance, and operational safety.
Accurate quantification of deuterium retained in lithium-containing materials is therefore essential for assessing their suitability under fusion-relevant conditions. Nuclear Reaction Analysis (NRA) using the ²H(³He,p)⁴He reaction [2,3] is one of the most sensitive techniques for hydrogen isotope measurements. Nevertheless, the presence of lithium introduces competing nuclear reactions whose emitted particles partially overlap with the deuterium signal, potentially limiting the detection capability.
In this work, the sensitivity limits of NRA for deuterium quantification in lithium-based materials were investigated using a Li-Sn alloy containing 15 at.% Li implanted in situ with 10 keV deuterium ions up to a fluence of 10¹⁷ions/cm². Measurements performed with a 2.3 MeV ³He beam demonstrate that the interference from lithium-induced reactions does not compromise reliable deuterium quantification. The detection limits obtained for the alloy are discussed and extrapolated to pure lithium systems.
These results highlight the capability of ion-beam analysis techniques to support the qualification of lithium-based functional materials for future fusion reactors. The methodology is directly relevant for studying hydrogen isotope retention and irradiation-induced effects in materials expected to operate under DEMO and IFMIF-DONES relevant environments.
[1] F.L. Tabarés, Plasma Phys. Control. Fusion 58 (2016) 014014
[2] J.P.S. Loureiro et al., Nucl. Mater Energy 12 (2017) 709
[3] R. Mateus et al., Nucl. Instrum. Methods Phys. Res. B 486 (2021) 55