Two-dimensional elemental mapping of simulated fuel debris using laser-induced breakdown spectroscopy

Abstract

ABSTRACT In this experimental study, two-dimensional elemental mapping of simulated fuel debris was conducted by laser-induced breakdown spectroscopy (LIBS). Since the real fuel debris was unavailable as a sample, simulated fuel debris was prepared from predicted materials including compounds and metals. An Nd:YAG laser at the second harmonic was used to generate plasma on the sample surface, and the optical emission from plasma was detected using an echelle spectrometer in the visible wavelength range from 435 to 650 nm. Due to the size and complexity of the collected dataset, the conventional data analysis method was ineffective; consequently, there arose a need to design a new data analysis method for study purposes. Therefore, in the present study, a method that is based on label-free chemometric methods, such as Principal Component Analysis and Multivariate Curve Resolution-Alternative Least Square methods, were implemented to obtain the spatial and spectral information regarding each constituent within the simulated sample. The study results demonstrated that the integration of LIBS and chemometric methods is a highly effective tool to obtain qualitative information regarding samples (e.g. fuel debris) with little or no prior knowledge.