Plasma Microchannel and Jet Enhanced by an Array of Ellipsoidal Microcavities

Plasma jet discharges are shown to be enhanced significantly, with respect to emission intensity, in the presence of ellipsoidal microcavities dispersed at uniform intervals along the gas flow channel. In these experiments, 25 microcavities were fabricated in the top and bottom faces of a gas flow channel having a rectangular cross section. Conducting film electrodes exterior to the glass structure, powered by a 20-kHz sinusoidal voltage, produced plasma along the entire channel as well as within the microcavities. Stronger optical emission and longer plasma jets were observed in this system than in an equivalent plasma jet system without microcavities.