Popis: |
WeinheimNegative and positive ions generated in an atmospheric-pressure DBD with double dielectrics were identified and their relative intensities characterized with variation of water vapor concentration in the discharge, gas residence time, and inter-electrode spacing. The most abundant negative ions were O−, OH−, CN−, CNO−, NO−2H2O, and NO−2 while the positive ions were dominated by N+, CH+2, N+2, CO+, HCO+, N2H+, O2+, H+(H2O)n, CNO+, and CN2O+. Increasing the water concentration in the discharge led to an increase in the intensity of H+(H2O)n, CNO+, and its hydrated clusters, while the intensity of all carbon containing species decreased. Increasing the residence time of the species in the plasma region decreased the concentration of O−, OH−, and NO−2, while the concentration of NO−3 increased. Changing the inter-electrodes spacing did not have any effect on the formation of ionic species in the discharge. |