Kinetics of radiative species in helium pulsed discharge at atmospheric pressure

Time variations of spectral line intensities of a helium dielectric discharge at atmospheric pressure have been analyzed by emission spectroscopy. A dielectric barrier controlled glow discharge with polymer films on the electrodes (O: 0.04 m, interelectrode distance: 0.005 m) is produced with a sinusoidal voltage of ca 800 Vr.m.s. The discharge is characterized by a current peak in each half cycle, its duration is of the order of 5 x 10(-6) s at 10(4) Hz. The radiative emission species are helium lines and mainly N-2, N-2(+), CO+, CO2 and OH bands coming from impurities which were in part desorbed from the polymer surfaces. From the time variations of band emissions, the main kinetic reactions at the origin of radiative species are discussed. (C) 1999 Elsevier Science S.A. All rights reserved.