Evaluation of the electron number and temperature in a sliding discharge

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

Caracas, Venezuela

Congreso; XII Latin American Workshop on Plasma Physics; 2007

A sliding discharge using two electrodes on an 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 N2+ ((l = 391.4 nm) have been measured and analyzed. 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.