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, ${\text{∼5×10}}^{15} {\mathrm{cm}}^{\mathrm{-3}},$ which has important value for materials applications. A theoretical model shows electron densities of ${\text{0.2–2×10}}^{11} {\mathrm{cm}}^{\mathrm{-3}}$ and characteristic electron energies of 2–4 eV for helium discharges at a power level of 3–30 W cm⁻³.