Energy generation and transport in an atmospheric pressure, audio frequency discharge

Summary form only given. Optical emission spectroscopy, using a neutral Bremsstrahlung technique, has been used to determine the plasma temperature and density in a coaxial dielectric barrier discharge (DBD). The experimental test cell is designed to investigate the plasma behavior and thermal power when operated at atmospheric pressure. The cell operates at a potential between 2-4 kV. The operational frequency can be varied to explore the effect of frequency change on the discharge parameters. Helium is used as the seed gas; however, other gases or gas mixtures were also used. Using the neutral Bremsstrahlung technique, for a pure helium discharge, the obtained electron temperature was /spl sim/0.9 eV for all ranges of discharge current and frequencies (within range of applicability of frequency changes). The electron density is linearly proportional to the discharge current density, and ranges between 1.2(10)/sup 7/ to 2.1(10)/sup 8/ cm/sup -3/. Based upon these average measurements of electron density and temperature, the power and the heating of the discharge are not well accounted for. This is due to the time varying nature and strong dependence on filamentary discharges with in a dielectric barrier discharge.