Estimation of Temperature in Aluminum Plasma Using Laser Induced Breakdown Spectroscopy

Abstract

Plasma produced by a 1.064 µm pulsed with a pulse duration of 6ns focused onto a pure aluminum solid sample (~99.99%) in air at atmospheric pressure is studied spectroscopy. An Echelle spectrograph coupled with a gate intensified charge coupled detector is used to record the plasma emissions. The plasma temperature was measured by time-resolved spectroscopy of aluminum neutral atom line emissions in the time window of 1-5 µs, using SahaBoltzmann plot method. The aluminum neutral lines were found to suffer from optical thickness over the entire delay times. Analytical relations were used and experimental procedures devised for evaluation of the self-absorption coefficients of several Al-lines, which are important to get reliable temperature measurements. The results shows that Al (I) lines have highest plasma temperature of 1.427 eV before correction against self absorption, while revealed a lowest temperature of 1.092 eV after correction