Temporal behavior of neutral and ionic lines emitted from a laser induced plasma on an aqueous surface

The temporal behavior of spectral lines emitted from a laser induced plasma has been studied. The plasma was created by using a Nd:YAG pulsed laser in air at atmospheric pressure focused on the surface of an aqueous solution. This work is an extension of previous published work J. Ben Ahmed, Z. Ben Lakhdar, G. Taieb, Kinetics of laser induced plasma on an aqueous surface, Laser chem. 20 (2002) 123–134.]. The time evolution of lines intensities emitted from Ca, Ca⁺, Mg and Mg⁺ has been experimentally observed and simulated using a simple theoretical approach based on electron–ion recombination. It was shown that the plasma temperature and electron density are correlated to the dynamics of plasma emission. Finally, the time evolution of the optical depth of Ca⁺ resonance line at 393.4 nm was also studied.