Radial structures of atmospheric-pressure glow discharges with multiple current pulses in helium

Radial structures of atmospheric pressure glow discharges in dielectric barrier discharge with multiple current pulses are investigated by a self-consistent two-dimensional fluid model. The simulation results show that the discharge current densities at different radial positions do not reach their peaks simultaneously, indicating that there exists a radial non-uniform structure. The time delay between the plasma ignitions in different positions become larger and larger in the successive current pulses. It is argued that the radial non-uniformity originates from the edge effects in the first current pulse, and grows in the successive current pulses by the activation-inhibition mechanism.