Development and study of properties of new atmospheric sources of plasma and microdischarges and their applications

The properties and applications of four different atmospheric pressure plasma sources developed in our laboratory were studied in this dissertation thesis. The first source was DBD discharge based atmospheric pressure plasma jet (APPJ) fed by argon. The generated plasma was analysed in terms of reactive and excited particles production and also the electrical parameters of discharge were studied. This source of plasma was used for the inactivation of pathogenic yeasts. The effect of argon plasma on deionized water, particularly the production of NO₂ - and NO₃ - ions was studied. The concentrations of these ions in water as function of the plasma application time were determined by using capillary electrophoresis and isotachophoresis. The second studied plasma source was negative corona discharge. It was used as a comparative source of reactive particles generating negative ions in the water. The third studied type of atmospheric pressure plasma source was APPJ based on spark discharge generated in air. The generated plasma was applied for treatment of healthy, cancer and stem human cells. Apoptotic and necrotic effects of plasma were confirmed by flow cytometry. The last studied source of plasma were microdischarges generated at different gas pressures, electrode gaps and different frequencies of the power generator. In the study we focused on identification of the breakdown voltages of microdischarges and explanation of the mechanism of discharge ignition. Diagnostics of all these types of plasma was mainly based on the measurement of electrical parameters of the discharges. The composition of neutral, excited and reactive particles in the plasma was measured by methods of optical emission spectroscopy (OES) and infrared spectroscopy absorption based on Fourier transformation (FTIR). (Author)