Impact of Pulsed Atmospheric-Pressure Glow Discharge on Nanometer-Thick Aluminum Films

The action of positive pulsed corona discharge in air at atmospheric pressure on aluminum thin-film cathode was studied in a 2- to 8-mm-wide gap at 5- to 15-kV voltage, 10- to 15-kHz pulse repetition rate, and pulse amplitude and duration of 10-20 mA and 300-500 ns, respectively. It has been established that, at relatively small average currents of 20-50 mu A, the corona discharge near cathode transforms into glow discharge. Due to discharge constriction on a transverse 1-mu m scale, the Joule's heating of a cathode layer can reach up to about 1000 K and produce local erosion of the cathode surface. This mechanism should be taken into account in analysis of the effects accompanying the interaction of discharge plasma with biological objects.