Temporal characterization of a plasma produced by interaction of laser pulses with water solutions

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 <500 ns. The intensity measurements of the lines of Ca II at 3158 Angstrom, 3179 Angstrom, 3706 Angstrom, 3736 Angstrom, 3933 Angstrom, 3968 Angstrom were used to obtain the electronic temperature T-e using a Saha-Boltzmann analysis. The broadening of the resonance line of Ca I at 4227 Angstrom was used to deduce the electronic density N-e , with the aid of the semi-classical theory of Stark broadening. A value of T-e \approx 28000 K decreasing slightly to 21000 K, and an exponential decay for N-e were found, with Ne approximate to 1.25 x 10(18) cm(-3) at 500 ns and tau(e) = (1200 +/- 50) ns.