Effects of O₂, CO₂and N₂on Discharge Characteristic of Multi-current Pulsed Discharge in Helium at Atmospheric Pressure

Order to study the effect of a small amount of O₂, CO₂ and N₂ on the discharge of atmospheric He multi-current pulse discharge, the current and voltage waveforms, Lissajious patterns and emission spectra of the discharge were studied experimentally.The results show that under the condition of constant applied voltage, with the increase of O2, CO₂ and N₂flux respectively, the number of current pulses does not change, but the peak width of current pulse becomes narrower, from μs to ns.The Lissajous figure shows that the applied voltage required for the first current pulse in glow discharge is much lower than that in filamentary discharge and the accumulated charge on the dielectric plate decreased obviously.This shows the discharge gradually transitioned from glow discharge to filamentary discharge.Their emission spectra show that this is mainly due to the gradual decrease of metastable He(2³S) atoms in the discharge space.