Estimation of temperature and electron density of laser-induced breakdown spectroscopy (libs) on river clam shell using hydrogen emissionlines

Abstract

The physical characteristic in term of temperature and electron density of the laser-induced plasma produced on a river shell sample has been investigated. The plasma was produced by an Nd: YAG laser beam (1064 nm) at low pressure (5 Torr) of air surrounding gas. Multi-elemental panoramic line spectra (200-900 nm) have been analysed at different delay times (0.1-5 μs) and gate width of 50 μs. The hydrogen emission lines namely Hα at 656.27, Hβ at 486.13 and Hγ at 434.04 nm were identified and utilized to evaluate the plasma parameters. The temperature and electron density of the produced plasma were estimated by means of Boltzmann Plot and Saha-Boltzmann method using the hydrogen emission lines. The result shows that the plasma temperature and electron density vary from about 5633 K to 8810 K and 3.7 × 1020 cm−3 to 9.7 × 1020 cm−3, respectively. The temperature and electron density of the plasma produced on the river shell sample conform the Maxwell distribution and Mc Whriter criteria for the laser induced plasma in local thermal equilibrium (LTE) condition.