Investigation of Dependency of Laser Irradiance on Plasma Parameters for Silica by Using Laser Induced Breakdown Spectroscopy (LIBS)

Abstract

The influence of changing laser irradiances on the plasma parameters, i.e. the electron temperature (Te) and electron number density (Ne), have been investigated by using Laser Induced Breakdown Spectroscopy (LIBS). This work aims to determine electron temperature and electron number density by analyzing the radiation emitting from the fused silica. For this purpose, evacuate the chamber to a base pressure of 10-6 Torr with the help of a turbo molecular pump. For the enhancement of emission intensity, the argon gas was filled at 20 Torr. The irradiance varies from 7.3 TW/cm2 to 10.7 TW/cm2. The calculated electron temperature from the Boltzmann plot method varies from 4950 K to 4975 K. Results showed the increasing trends of electron temperature with an increase in laser irradiances. Electron number density was calculated from the Stark-Broadened line profile, and it varies from 4.2 × 1017 cm-3 to 9.9 × 1017 cm-3. This study revealed that at low laser irradiance, the electron number density decreases, whereas at higher laser irradiance, the electron number density increases.