Numerical investigation of co-axial DBD: Influence of relative permittivity of the dielectric barrier, applied voltage amplitude and frequency

In this work, a one-dimensional numerical fluid model is developed for co-axial dielectric barrier discharge (DBD) in pure helium and a parametric study is performed to systematically study the influence of relative permittivity of the dielectric barrier and the applied voltage amplitude and frequency on the discharge performance. Discharge current, gap voltage and spatially averaged electron density profiles are presented as a function of relative permittivity and voltage parameters. For the geometry under consideration, both the applied voltage parameters are shown to increase the maximum amplitude of the discharge current peak up to a certain threshold value, above which it stabilized or decreased slowly. The spatially averaged electron density profiles follow a similar trend as the discharge current. Relative permittivity of the dielectric barrier is predicted to have a positive influence on the discharge current. At lower frequency it is also shown to lead a transition from Townsend to glow discharge mode. Spatially and time averaged power density is also calculated and is shown to increase with increasing relative permittivity, applied voltage amplitude and frequency.