Large area, atmospheric pressure plasma for downstream processing

An atmospheric-pressure plasma discharge apparatus comprising in combination:

• a first electrode having a cylindrical inner surface and a first axis of symmetry;
• a plurality of parallel tubes forming a second cylindrical electrode interior to said first electrode and having a second axis of symmetry co-axial with the first axis of symmetry, each tube of said plurality of tubes having an outer surface spaced apart a first chosen distance from the inner cylindrical surface of said first electrode, the outer surface of each tube of said plurality of tubes further being spaced apart a second chosen distance from the outer surface of an adjacent tube thereto;
• an rf power supply in electrical contact with either of said first electrode or each tube of said plurality of tubes for providing rf power to said first electrode or said second electrode, the unpowered electrode of said first electrode or each tube of said plurality of tubes being placed in electrical contact with a ground electrical potential;
• means for cooling each tube of said plurality of tubes to a chosen temperature;
• and
• means for flowing a gas into the annular space between said first electrode and said second electrode and out of the annular space between said first electrode and said second electrode between the spaced-apart outer surfaces of each tube of said plurality of tubes;
• whereby an atmospheric pressure plasma is generated between said first electrode and said second electrode.