Abstract

The temporal evolution of a plasma formed by the interaction of a Nd-YAG 10 ns laser pulse with the surface of aqueous solutions of CaCl2, has been observed by analyzing the variation of the emission spectra of ions and neutral atoms in the time interval after the laser pulse, 500 ns < t < 5000 ns. The intensity measurements of the lines of CaII at 3158 Å, 3179 Å, 3706 Å, 3736 Å, 3933 Å, 3968 Å were used to obtain the electronic temperature Te using a Saha-Boltzmann analysis. The broadening of the resonance line of CaI at 4227 Å was used to deduce the electronic density Ne, with the aid of the semiclassical theory of Stark broadening. A value of Te ≈ 28000 K decreasing slightly to 21000 K, and an exponential decay for Ne were found, with Ne ≈ 1:25 × 1018 cm-3 at 500 ns and τe=(1200±50) ns.