Discharge-assisted LIBS for the analysis of hydrogen isotopes content in tungsten samples

Fuel retention within the walls poses a significant challenge in the design and operation of nuclear fusion devices. Laser-Induced Breakdown Spectroscopy (LIBS) emerges as a promising solution for addressing this issue, with applications observed in both tokamaks [1]and plasma-wall interaction research facilities [2]. LIBS offers several advantages, including in-situ operation and depth profilometry capabilities. However, the presence of deuterium (D) and tritium (T) - the primary species of interest - is often complicated by the interference of loaded hydrogen. The coexistence of hydrogen (H) alongside D creates spectral separation challenges due to emission line overlaps, particularly susceptible to Stark broadening following the ablation pulse. To achieve accurate LIBS measurements of D and T fuel retention, several conditions must be met: low laser energy to minimize interference, single-pulse detection for detailed profilometry, and a sufficiently delayed measurement window post-pulse to mitigate line broadening effects. These requirements necessitate the integration of auxiliary techniques to enhance the spectral emission signal. In this study, we investigate the potential of electric discharge-assisted LIBS across various pressure and environmental gas conditions, as well as different discharge configurations, to optimize spectral emission signal.