An atmospheric pressure plasma source

An atmospheric pressure plasma source operated by radio frequency power has been developed. This source produces a unique discharge that is volumetric and homogeneous at atmospheric pressure with a gas temperature below 300 °C. It also produces a large quantity of oxygen atoms, ∼5×1015 cm−3, which has important value for materials applications. A theoretical model shows electron densities of 0.2–2×1011 cm−3 and characteristic electron energies of 2–4 eV for helium discharges at a power level of 3–30 W cm−3.