Comprehensive study on discharge characteristics in pulsed dielectric barrier discharges with atmospheric He and CO2

Abstract

The atmospheric pulsed dielectric barrier discharges have been studied extensively for their huge potential in plasma applications. In this paper, a comprehensive study of discharge characteristics in atmospheric He and CO2 discharges driven by pulsed voltages is carried out by experimental measurements and numerical simulation. The computational data indicate that during a plateau phase in the pulsed CO2 discharge, a strong electric field of 2.6 kV/cm always sustains to drive the heavy ions of CO 2 + and CO 3-to the surfaces of dielectric material, forming a discharge current density of about 2.5 mA/c m 2. The experimental measurements and simulation data show that the duration of the plateau phase has a significant influence on the discharge characteristics of pulsed CO2 discharges but only slightly affects on the discharge evolution in pulsed He discharge. By increasing the duration of the plateau phase, the surface charges accumulated on the dielectric materials are also enhanced, and then, a stronger induced electric field is established in the discharge region, resulting in a larger discharge current density during the pulse fall phase, which is not observed in the pulsed He discharge. In this study, the different discharge behaviors of pulsed He and CO2 discharges are compared in detail, which can enhance the understanding of the underpinning discharge physics, suggesting the optimized ways to utilize pulsed discharges with various plasma-forming gases.