Influence of particle location within plasma and focal volume on precision of single-particle laser-induced breakdown spectroscopy measurements

The effect of the location of particles within the plasma volume on the laser-induced breakdown spectroscopy signal for single-particle measurements is investigated. Three methods of collecting plasma emission are compared to determine the influence of plasma imaging on particle hit detection rates and signal precision. Imaging larger regions of the plasma volume improves particle detection rates. Spatial integration of the signal from the entire plasma volume tends to reduce uncertainty in the signal caused by variability in the location of particles within the plasma. Additionally, the use of spatially resolved measurements is found to maximize the particle detection efficiency. The use of spatially resolved measurements gives information about the location of particles within the plasma, which could be used to develop improved hit detection criteria, and to improve the precision of single-particle measurements. (c) 2005 Elsevier B.V. All rights reserved.