Characteristics of a barrier discharge in monatomic gases

Summary form only given. Experiments in a simple parallel-plate dielectric-barrier discharge show that the structure of monatomic gases is very differently from molecular gases. Time-resolved images show diffused discharge for monatomic gases and filamentary discharge for molecular gases. In addition, current waveforms also show a marked difference. Two-dimensional streamer calculation show that in a monatomic gas the discharge is diffused compared to molecular gases. The high ionization coefficient at low reduced field, the high diffusion constant and the high secondary ionization coefficient of monatomic gases can account for these differences. Also an empirical relationship for power and voltage is derived which shows good agreement with experimental results for both monatomic and molecular gases.