Laser-induced breakdown spectroscopy for the detection and characterization of explosives

Laser-induced breakdown spectroscopy (LIBS) has been developed as a technique for the detection and characterization of energetic materials for over a decade. LIBS possesses ideal characteristics for detection applications—it is high-throughput, provides real-time analysis, requires no sample preparation, is minimally destructive, and can be configured for portable or standoff applications. Here, we highlight the important research that has led to the current state-of-the-art for LIBS technology in the field of explosives research. Numerous fundamental studies have been performed that describe the decomposition mechanisms of explosives in the microplasma, and how experimental parameters influence emission signals. Data analysis methods that have been employed to discriminate LIBS spectra from explosive and nonexplosive materials will also be discussed. These methods include a variety of techniques, from simple spectral correlations to more complicated multivariate analysis methods. An overview of practical applications for explosives detection will be presented that includes collecting LIBS spectra from explosive residues at standoff distances, demonstrating the ability to separate explosive samples from background clutter, and the detection and identification of explosive-related materials. Finally, a more recent avenue of study involves using properties from the laser-generated microplasma to evaluate the performance of energetic materials.