Interactions between atmospheric pressure plasma jet and deionized water surface

This study describes atmospheric pressure Ar plasma jet interactions with and without deionized (DI) water. The plasma jet was operated under an applied voltage in the range 1.8-2.5 kV with a 50 kHz sinusoidal wave. The dissipated power without DI water measured at the grounded copper tape increased along with the applied voltage. However, the power with DI water saturated above 2.3 kV. The hydroxyl radicals and plasma electrons, as well as the emission intensities of atomic oxygen and argon increased rapidly via plasma interaction with DI water beyond an applied voltage of 2.3 kV, whereas the electron temperatures decreased significantly. The experimental results show the possibility of identifying the region of interaction between plasma and DI water surface using these electrical and optical characteristics, as well as the plasma parameters of electron temperature and density.