  The plasma-liquid interaction is an important issue in plasma technology. The
simulation of discharge in spherical bubbles in the water that produced
plasma-activated water (PAW) is investigated using finite element methods (FEM)
for a simulated 2D dielectric barrier discharge in three different geometries.
The electron density changes with voltage, frequency, dielectric thickness, and
bubble radius are investigated in different time duration. The results show
that electron density increases linearly by increasing voltage, frequency and
bubble radius, while it is vice versa for dielectric thickness. High plasma
density indicates sufficient plasma-water interaction.
