Diagnostics of dielectric barrier discharges in noble gases: Atmospheric pressure glow and pseudoglow discharges and spatio-temporal patterns

We present experimental, results of atmospheric pressure glow discharges (APGD) in a dielectric barrier discharge reactor. These are examined in different noble gases, and in the N-2/O-2 system (air and pure N-2), under varying experimental conditions (frequency f; gap length d; and electric field intensity E). Discharge diagnostics have been carried out using ultrahigh speed imaging, and synchronous dual-detection of light emission and current-voltage measurements, the former using a photomultiplier. The time evolutions of the discharges and of columnar patterns in regular geometric arrangements at atmospheric pressure. under different experimental conditions are reported for all of the noble gases studied here. We present evidence that columnar patterns and APGD are manifestations of the same discharge physics, which is discussed with reference to recent work reported by others.