Time and Spatially Resolved Spectrum Study of Laser-Induced Plasma in Reduced Pressure Atmospheres of Argon and Helium

Abstract

In order to find the optimum conditions which give best line-to-background ratio as well as high spectral line intensity, the emission characteristics of a Nd: YAG laser-induced plasma were studied in argon and helium atmospheres at reduced pressures from 760 to 1 Torr by using a combination of space and time resolution. From the experimental results, the conditions of a 200 Torr argon, an observation position of about 1.5mm above the sample surface, and a gate delay time of 2μs measured after the initiation of the laser pulse were established as optimum.