Analysis and Spectral Assignments of Mixed Actinide Oxide Samples Using Laser-Induced Breakdown Spectroscopy (LIBS)

In this paper, we report for the first time the identification and assignments of complex atomic emission spectra of mixed actinide oxides using laser-induced plasma spectroscopy or laser-induced breakdown spectroscopy (LIBS). Preliminary results of LIBS measurements on samples of uranium dioxide (UO₂)/plutonium dioxide (PuO₂) and UO₂/PuO₂/americium dioxide (AmO₂)/neptunium dioxide (NpO₂) simulated fuel pellets (or mixed actinide oxide samples) are reported and discussed. We have identified and assigned >800 atomic emission lines for a UO₂/PuO₂/AmO₂/NpO₂ fuel pellet thus far. The identification and assignments of spectral emission lines for U, Pu, and Am are consistent with wavelength data from the literature. However, only a few emission lines have been assigned with a high degree of confidence for Np compared with atomic emission data from the literature. We also indicate where atomic emission lines for Cm would most likely appear in the spectral regions shown. Finally, we demonstrate that a LIBS system with a resolving power of approximately 20 000 is adequate for analyzing complex mixtures of actinide elements within the same sample.