Plasma nozzle array for providing uniform scalable microwave plasma generation

A method for generating plasma plumes through a microwave plasma nozzle array, comprising the steps of:

• directing a first pair of microwaves into a microwave cavity in opposing directions along a first axis;
• directing a second pair of microwaves into the microwave cavity in opposing directions along a second axis, the first axis being normal to the second axis such that the first and the second pairs of microwaves cross and interfere with each other to form high-energy regions that are arranged in a matrix pattern and are stationary within the microwave cavity;
• adjusting a phase of at least one of the microwaves to control the high-energy regions, the high-energy regions having a width where an amplitude of the microwaves exceeds a threshold value;
• providing a plurality 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 material which is substantially transparent to microwaves and further the gas flow tube surrounds at least 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 a plurality of nozzle arrays 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 in each nozzle is disposed in the microwave cavity so that each nozzle element of the nozzle arrays is configured to receive microwave energy from a corresponding one of the high-energy regions;
• 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.

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 through separate waveguides such that the microwaves are injected into the microwave cavity via two opposite openings formed on a wall of the microwave cavity, interfere and form a standing microwave pattern that is stationary within the microwave cavity;
• adjusting a phase of at least one of the microwaves to control high-energy regions generated by the standing microwave pattern, the high-energy regions having a width where an amplitude of the microwaves exceeds a threshold value;
• providing a plurality 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 material substantially transparent to microwaves and further the gas flow tube surrounds at least 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 nozzle array at least partially in the microwave cavity so 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 the rod-shaped conductor 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.