Infrared laser induced plasma diagnostics of silver target

Abstract

In the present work, the optical emission spectra of silver (Ag) plasma have been recorded and analyzed using the laser induced breakdown spectroscopy technique. The emission line intensities and plasma parameters were investigated as a function of lens to sample distance, laser irradiance, and distance from the target surface. The electron number density (ne) and electron temperature (Te) were determined using the Stark broadened line profile and Boltzmann plot method, respectively. A gradual increase in the spectral line intensities and the plasma parameters, ne from 2.89 × 1017 to 3.92 × 1017 cm−3 and Te from 4662 to 8967 K, was observed as the laser irradiance was increased 2.29 × 1010–1.06 × 1011 W cm−2. The spatial variations in ne and Te were investigated from 0 to 5.25 mm from the target surface, yielding the electron number density from 4.78 × 1017 to 1.72 × 1017 cm−3 and electron temperature as 9869–3789 K. In addition, the emission intensities and the plasma parameters of silver were investigated by varying the ambient pressure from 0.36 to 1000 mbars.