Patent ID: 7806077

Claim:
A method for generating plasma plumes through a microwave plasma nozzle array, comprising the steps of: directing microwaves into a microwave cavity in opposing directions such that the microwaves interfere with each other and form a standing microwave pattern that is stationary within the microwave cavity; adjusting a phase of at least one of the microwaves to form high-energy regions in the standing microwave pattern, the high-energy regions having a width where an amplitude of the microwaves exceeds a threshold value; providing an array of nozzles, each of the nozzles including: a rod-shaped conductor having a first end and a second end where the first end being a leading end of the rod-shaped conductor, and a gas flow tube having a first end portion disposed inside the microwave cavity and a second end portion disposed outside of the microwave cavity, the first end portion is made of a substantially microwave transparent material and further the gas flow tube surrounds at least a part of the rod-shaped conductor in such a manner that the second end portion is in proximity to the first end of the rod-shaped conductor, and a portion of the gas flow tube is connected to the microwave cavity at a location where the gas flow tube surrounds the rod-shaped conductor; and disposing the array of nozzles in the microwave cavity such that a middle portion of the rod-shaped conductor is held with respect to said gas flow tube via a holding member, at least the second end of each of the rod-shaped conductors is disposed in the microwave cavity to receive microwave energy from a corresponding one of the high-energy regions of the standing microwave pattern; the first end is being outside the microwave cavity and the second end is suspended free in the microwave cavity in such a manner that the second end is free from contact with any walls forming the microwave cavity and any members that are in contact with said walls of the microwave cavity so that plasma is formed outside of the microwave cavity.