Plasma generating nozzle having impedance control mechanism

A plasma generating system, comprising:

• a microwave generator for generating microwave energy;
• a power supply connected to the microwave generator for providing power thereto;
• a microwave cavity;
• a waveguide operatively connected to the microwave cavity for transmitting microwave energy thereto;
• an isolator for dissipating microwave energy reflected from the microwave cavity;
• and
• at least one nozzle coupled to the microwave cavity, each one of said at least one nozzle comprising:
• a housing having a substantially cylindrical space formed therein, the space forming a first gas flow passageway;
• a rod-shaped conductor disposed in the space and having a portion extending into the microwave cavity for receiving microwave energy and operative to transmit microwave energy along a surface thereof so that the microwave energy transmitted along the surface excites gas flowing through the space;
• and
• an impedance controlling structure configured to vary an impedance of the nozzle, the impedance controlling structure comprising a first portion located within the gas passageway, said first portion being distinct from the rod-shaped conductor and;
• said each one nozzle having an opening through which is emitted a plasma plume.