Speaker
Description
Boron layers are widely employed in magnetic-confinement fusion devices due to their strong oxygen gettering capability and their role in reducing impurity release from plasma-facing components. Accurate characterization of boron film thickness, erosion behaviour using laser ablation, and fuel retention is essential for predictive plasma–wall interaction modelling in ITER- relevant conditions[1]. Recent studies using LIBS have demonstrated quantitative detection of ultrathin boron layers on tungsten substrates and established calibration strategies for high-resolution surface analysis in fusion environments [2], [3]. Building on these developments, the present work investigates thicker and fuel-loaded boron coatings representative of boronized first-wall surfaces.
Boron films of 500 nm and 1000 nm thickness deposited on Si and W substrates, along with corresponding deuterium-loaded variants, are analyzed predominantly by depth-resolved ps-LIBS. The short-pulse excitation enables controlled material removal with reduced thermal diffusion, allowing the evolution of deuterium emission to be quantified as a function of ablation depth. Complementary ion-beam techniques are employed to obtain absolute deuterium areal densities and depth distributions, providing independent reference profiles for evaluating the accuracy of the LIBS-derived depth information[4,5].
Systematic comparison of pristine B and D-loaded B layers enables extraction of the boron ablation rate and identification of modifications to crater formation induced by retained deuterium. The resulting dataset elucidates the interplay between fuel retention and ablation dynamics in boron coatings and supports the establishment of a depth-calibrated, quantitative LIBS framework for fuel-retention diagnostics in fusion devices. This work extends LIBS beyond ultrathin boron films and addresses key analytical requirements for assessing erosion and D retention in future reactor-scale plasma-facing components.
References:
[1] J. Winter et al., Journal of Nuclear Materials, 162–164 (1989) pp. 713–723.
[2] H. Wu et al., Nuclear Materials and Energy, 45 (2025) 102018.
[3] H. Wu et al., Nuclear Materials and Energy, 41 (2024) 101812.
[4] P. Veis et al., Nuclear Materials and Energy, 25 (2020) 100809.
[5] R. Mateus et al., Elemental analysis of divertor marker tiles exposed during the 2018 (C3), 2019 (C4) and 2020 (C5) WEST campaigns, PFMC 2025 conference.