Depth-resolved and time-resolved investigations of Er2O3 ceramics after static lithium corrosion by using LIBS at different pressures

Liquid metal lithium can cause severe corrosion on the surface of fusion reactor blankets and first-wall metal materials. Oxidized erbium ceramic has been widely studied as a candidate material for the self-cooling blanket system of tokamak fusion reactors. In this study, time-resolved picosecond laser-induced breakdown spectroscopy (ps-LIBS) was used to investigate the time evolution process of laser-induced plasma (LIP) of Er2O3 samples in air at different pressures. The pressure-time windows with high signal-to-background ratio and high signal-tonoise ratio under LTE conditions were determined. The composition depth distribution of the Er2O3 ceramic after static corrosion by lithium was analyzed. The number of laser pulses were linearly proportional to the laser ablation depth as measured by a three-dimensional profilometer. As the number of pulses increased, the relative intensities of the 610.353 nm and 812.645 nm characteristic lines of the corroding element Li gradually decreased, while the relative intensities of the 405.547 nm and 405.951 nm characteristic lines of the base element Er gradually increased. The laser pulse number at which the relative peak intensities of Er and Li reached a steady state showed a trend of first increasing and then decreasing with increasing pressure. In addition, the results of laser ablation depth under different environmental pressures indicated that the depth resolution of the analysis of anti-corrosion Er2O3 ceramic materials can be controlled by the environmental gas pressure.

Automated summary

This study investigated the time evolution process of laser-induced plasma of Er2O3 samples in air at different pressures using time-resolved picosecond laser-induced breakdown spectroscopy. The results showed that the pressure-time windows with high signal-to-background ratio and high signal-to-noise ratio under LTE conditions were determined. The depth resolution of the analysis of anti-corrosion Er2O3 ceramic materials can be controlled by the environmental gas pressure.