Visualizations with high speed framing camera of the evolutive phases related to the development of a microplasma in ionic solution

Abstract

This technical article presents experimental results of qualitative analyses through photos with high speed framing camera of the evolutive phases related to the development of a microplasma in form of an electric discharge that has been generated in ionic solution with defined electrical conductivity. These analyses became possible firstly by the construction of a experimental device consisted of an electric voltage pulse generator electrically connected with the high speed framing camera and with two electrodes positioned at a micrometric distance from each other to form an electrochemical cell. The application of an electric voltage pulse between the electrodes in a predefined time in microseconds under special experimental conditions using the generator triggers in the same time the high speed framing camera. The camera makes it possible to obtain extremely rapid various photos of the chemical and physical phenomena occurring between the electrodes. Through the obtained photos, it can be verified that the development of a microplasma in ionic solution is firstly the direct result of the formation of a volumetric quantity of gas within the space between the electrodes. The intensity of the electric voltage pulse applied at the electrodes conduces to the “rupture” of the dielectric properties of the gas that has been generated, thus producing a microplasma with special physical characteristics. It is also explained that the gas formed between the electrodes is hydrogen resulting from the electrochemical reactions which have been developed in ionic solution after application of the electric voltage pulse between the electrodes.