Laser Plasma Generation in Liquids. Possible Perturbations of the Boundary Layer Dynamics in a Metallic Surface in a Cell Filled With Conducting Liquid

In the surrounding region of a metal immersed in an aqueous solution, a boundary layer with a complex structure is formed. When pulsed-laser-induced plasma is produced in the bulk of the liquid, galvanic pulses appear in the short term, while the pH, electrode potential, and temperature of the liquid (properties of the system related to the conduction mechanisms) vary in the long term. To prove that the plasma perturbs the dynamics of the boundary layer, via the shock wave resulting from the dielectric breakdown, the beam of a Nd
⁺³
:YAG laser was focused onto a cell containing a metal piece to create a plasma plume near its surface. To this end, the dependence of the galvanic pulse amplitude with both the distance from the plate to the plasma and the laser pulse energy was investigated. Moreover, the pH, the electrode potential of the metal, and the temperature variation of the solution along the duration of the experiments were systematically monitored. The results obtained suggest that the perturbation of the interface by the shock wave generated as a result of the laser-produced plasma is a reasonable hypothesis.