Optical Emission Analysis of Molecular Nitrogen by Using a Self-Resonating Dielectric Barrier Plasma Reactor

We present a spectroscopic investigation of molecular nitrogen using a self-resonating co-axial dielectric barrier plasma reactor. The properties of the nitrogen plasma generated were recorded as functions of radio frequency (27.12 MHz), power (20–50 W) and gas pressure (0.1–60 mbar). The intensity distribution of the transitional structure of the electronic bands C³Π_u →B ³Π_g, B ²Σ_u⁺→X ²Σ_g⁺ and D ²Π_g→A ²Π_u was measured as a function of gas pressure. Relative energy efficiency (total emitted intensity from the plasma I_t divided by total electric power to the discharge P), as high as 14% can be obtained at a dissipated electrical power level of 20 W and a pressure of 10 mbar.