Effectiveness of Argon Nanobubbles in Realizing Enhanced Optical Sensitization for Laser-induced Breakdown Spectroscopy

Abstract

This chapter describes the validity and usefulness of laser-induced breakdown spectroscopy (LIBS) measurements enhanced by argon nanobubbles. The use of argon nanobubbles in the LIBS system revealed higher sensitivity as compared to other conventional methods that are used for LIBS solution measurements. To create the nanobubbles, argon gas was pumped into water, forming bubbles less than 100 nm in diameter. The solution of dissolved argon bubbles was used to measure (1) the atomic spectrum of hydrogen (λ = 656 nm) from the water molecules (H2O) in the solution, and (2) the atomic spectrum of nitrogen (λ = 399.5) from the air bubbles in the solution. These experimental results demonstrated that argon nanobubbles are able to instantaneously retain plasma during the excitation/relaxation period, which is essential for highly sensitive spectral measurements. The intensity of nitrogen spectra (measurement (2)) obtained from the argon-air nanobubbles in water was much higher than that of the spectra obtained from normal LIBS air measurements.KeywordsLaser induced break spectroscopyLIBSArgon nanobubblesOptical sensitization