Electric field determination of methane in a glow discharge using stark broadening measurements

Summary form only given. The use of hydrocarbons as working gases for plasma discharges is of interest for a number of reasons. The use of arc ignition in combustion engines has persisted since their invention, but nonthermal plasma discharges offer potential for improving combustion characteristics1. Additionally, plasmas provide a means for the conversion of methane into higher, more attractive, hydrocarbons2 as well as plasma reforming for hydrogen production. Here, we present preliminary spatially resolved electric field measurements, made by use of the observed Stark effect, in a glow discharge with methane as a working gas. The discharge was sustained by circular, planar electrodes in a pyrex cross. Initial qualification of the system was done using helium and compared to previous studies3. Subsequent operation was sustained in a methane environment (using helium as a tracer gas) with supporting diagnostics used to verify discharge models. These measurements are critical for accurate understanding and modeling of the plasma chemistry as they provide a direct quantification of the reduced electric field. The qualification of these optical diagnostics is a necessary precursor to further research into pulsed, nonthermal plasmas which also have applications in supersonic and hypersonic transport4.