Evaluation of the electron number and temperature in a sliding discharge

H KELLY; R SOSA; D GRONDONA; A MARQUEZ; V LAGO; G ARTANA

PHYSICA SCRIPTA

IOP

Año: 2008 vol. T131 p. 14001 - 14005

0031 8949

A sliding discharge using two electrodes on a dielectric layer (upper electrodes) and a third electrode on its reverse side, facing the upper inter-electrode gap (lower electrode) was generated in air at atmospheric pressure. Application of a high dc negative voltage to one of the upper electrodes and to the lower electrode, and a high ac voltage to the other upper electrode generates a stable and homogeneous surface plasma (plasma sheet) in the upper electrode’s gap. In this work, the plasma sheet optical emission of the spectral bands corresponding to the 0–0 transition of the second positive system of N2 (l = 337.1 nm) and the first negative system of N+2 (l = 391.4 nm) has been measured and analysed. It was found that the plasma sheet consisted of a set of cathode-directed streamers. The streamer generation frequency and its transit time across the inter-electrode gap have been studied. On the basis of a reliable atomic model to interpret the line emission, the total electron number at the streamer head and the electron temperature have been derived.