Optimization of Laser-Induced Breakdown Spectroscopy for Liquid Samples at Millijoule Pulse Energies

摘要

A study is being carried out investigating the capabilities of laser-induced breakdown spectroscopy for analysis of water samples at pulse energies from sub-millijoule to 100 mJ per pulse. The sub-millijoule energy regime for LIBS of water samples is not well investigated, and optimal conditions need to be identified. Optimization of the limit of detection of contaminants in water requires detailed characterization of the plasma evolution, the line emission and the sources of background noise. Pulse energies from 3 mJ to 100 mJ focused with a 30 cm lens have been tested for Na in water, resulting in detection limits from 200 ppm to 2 ppm respectively. Scaling to sub-millijoule energies using shorter focal length lenses is currently under investigation.