Characteristics of dielectric barrier discharge microplasma

Emission spectroscopy analysis and imaging technique were used to study the microplasma phenomena. The microplasma discharge in Ar and N₂/Ar was analyzed along the discharge gap area and also for specific periods of time during the discharge. Spatial and temporal distribution showed the propagation of light emission from anode towards cathode. The phenomena could be divided in stages: electron avalanche from cathode and the anode, cathode direct streamer development, cathode layer development, cathode layer enhancement and final stage of cathode layer decay. The light emission was measured up to 365 ns as long as the discharge current was measured. The peak of Ar I at 696.5 nm was used to estimate the electron density using Stark broadening method. The calculated value of electron density ne= 10¹⁴/cm³ is specific for atmospheric pressure nonthermal plasmas.