Patent ID: 7365956

Claim:
A system for producing superoxide ions in the air at atmospheric pressure comprising: a. an enclosed volume of gas, the inside of which comprises a first region, the outside of which comprises a second region, the boundary of which comprises a barrier between said first and second regions and said second region being atmospheric air, and, b. a first electrode in said first region in close proximity to the inner surface of said barrier such that a first subvolume between said first electrode and said barrier is established and is small compared to said enclosed volume whose boundary is defined by said barrier, and c. means for said gas in said first region to pass freely into said first subvolume between said first electrode and said barrier, one such means being holes in said first electrode or said first electrode being a meshlike structure, and d. a second electrode on the outer surface of said barrier, and e. said second electrode having holes so that gas in said second region can move to and from the outer surface of said barrier, and f. said barrier being a dielectric material, and g. means for holding said second electrode at a D.C. potential below ground, that is a negative D.C. potential, and h. means for applying an AC voltage of adequate amplitude and frequency to said first electrode to sustain a partially ionized plasma in said first subvolume, whereby electrons in said plasma diffuse through said barrier towards said second electrode, and i. the thickness of said barrier being thin enough that a plasma is generated in said first subvolume and thick enough so that dielectric breakdown does not occur in said barrier, and the interaction of said plasma with said barrier and said negatively biased second electrode and said atmospheric air in said second region thus producing negative ions in said second region.