PROCEEDINGS ARTICLE | May 8, 2009
Proc. SPIE. 7304, Chemical, Biological, Radiological, Nuclear, and Explosives (CBRNE) Sensing X
KEYWORDS: Carbon, Principal component analysis, Statistical analysis, Data modeling, Argon, Nitrogen, Laser induced breakdown spectroscopy, Explosives, Statistical modeling, Atmospheric modeling
This study makes a comparison of LIBS emission from molecular species in plasmas produced from organic
residues on a non-metallic substrate by both a 5 ns Nd:YAG laser (1064 nm) and a 40 fs Ti:Sapphire laser (800 nm)
in air and argon atmospheres. The organic samples analyzed had varying amounts of carbon, nitrogen, hydrogen,
and oxygen in their molecular structure. The characterization was based on the atomic carbon, hydrogen, nitrogen,
and oxygen lines as well as the diatomic species CN (B2Σ+ - X2Σ+) and the C2 (d3Πg - a3Πu). Principal Component
Analysis (PCA) was used to identify similarities of the organic analyte via the emission spectra. The corresponding
Receiver Operating Characteristics (ROC) curves show the limitations of the PCA model for the nanosecond regime
in air.
