Laser-induced breakdown spectroscopy: A new technique for nondestructive analysis of solutions

Laser-induced breakdown spectroscopy has been applied to the continuous determination of uranium in solutions. The technique is rapid, non-invasive, and unaffected by radioactivity. Powerful laser pulses are focused through an optical access onto the solution surface to produce a hot spark plasma. In experiments on static solutions, uranium concentrations between 0.1 and 300 g/L were determined, using a pulsed Md:YAG laser and a time-gated photodiode array. A concentration of 4.2 g/L was measured with 1.0% precision in 3 minutes. Substances that absorb at the laser wavelength, suspended materials, and variations in the acidity of the solution have little or no effect on the results. Experiments are in progress on flowing streams contained in a test loop that simulates plant operating conditions. 1 ref., 3 figs., 3 tabs