Patent ID: 8552335

Claim:
A plasma jet apparatus for performing plasma processing of an article, comprising: a central electrode shaped as a plate having a height extending in a first direction, and a length extending perpendicularly to the height, one outer electrode or a pair of outer electrodes shaped to extend at both sides of the central electrode and being substantially parallel to the central electrode, each of said outer electrodes having an inner surface facing the central electrode, and an outer surface opposite the inner surface, a dielectric material layer disposed at the inner surface of each of the outer electrodes and substantially parallel to the central electrode, wherein the dielectric material is spaced apart from the central electrode to create a plasma discharge lumen between the dielectric material layer and the central electrode extending in the first direction between a distal end and a proximal end; a supply opening disposed at the distal end of the discharge lumen, for supplying a plasma producing gas to the discharge lumen, wherein the discharge lumen is open to the atmosphere in the first direction at the proximal end, a power source for providing a voltage between the central and the outer electrodes, wherein at the proximal end the apparatus comprises at each of both sides of the central electrode an extension made of a dielectric material and a return leg made of a dielectric material; wherein the extension is arranged beyond the outer electrode when viewed along the first direction, wherein the extension extends outwardly between the dielectric material layer and the return leg along a second direction substantially perpendicular to the first direction; wherein the return leg is arranged beyond the outer surface of the outer electrode when viewed in the second direction, wherein the return leg extends along the first direction from the extension towards the distal end, and wherein the return leg is spaced apart from the outer electrode.