Plasma Produced by Laser : Laser interaction with solid targets and the characteristics of the plasma produced

Laser-induced plasma spectroscopy (LIPS), is being used as an analytical method by a growing number of research groups. In the present work we study the effect of the laser beam energy on the properties of the plasma generated by focusing an intense laser beam on Al solid target in air at atmospheric pressure. Plasma is generated using Nd:YAG pulsed laser at 1064 nm wavelength, 6 ns pulse duration with maximum pulse energy of 750mJ. The emission spectrum is collected using an Echelle spectrometer equipped with ICCD camera Andor type. Measurements of temperature and electron density of the produced plasmas at different laser energies and at different delay times are described using different emission spectral lines. Based on LTE assumption, excitation temperature is determined from the Boltzmann plot using O I spectral lines at 777.34, 794.93, and 848.65 nm and the electron density are determined from Stark width of Al II at 281.6 and 466.3 nm. The determined density is compared with the density determined from HQ, spectral line.