Optical development of a multi-pulse dielectric barrier glow discharge in atmospheric-pressure helium

In order to study the mode transition and the mechanism of multi-pulse dielectric barrier glow discharge, three-pulse glow discharge in 6 mm helium was obtained. The electrical signals were measured, and short exposure time images were taken using an intensified charge-coupled device (ICCD). The gray value of the images was extracted and the corresponding light distribution was drawn to make the images more visualized. According to the features of discharge images, the optical development was analyzed by dividing the current pulses into different stages. Moreover, the discharge modes and the transition law of all stages were studied systematically, and the mechanism of discharge was investigated. The results show that, in the initial stage, the discharge has an anode luminous structure of Townsend discharge. Then the discharge transits to glow mode with a structure of positive column, Faraday dark space and negative glow space. The weak luminescence between adjacent pulses still has a glow discharge structure, which strongly suggests that the discharge does not extinguish but maintains a weak glow discharge during these stages.