Microwave plasma nozzle with enhanced plume stability and heating efficiency, plasma generating system and method thereof

摘要

Systems and methods for generating microwave plasma are disclosed. The present invention provides a microwave plasma nozzle (26) that includes a gas flow tube (40), and a rod-shaped conductor (34) that is disposed in the gas flow tube (40) and has a tip (33) near the outlet of the gas flow tube (40). A portion (35) of the rod-shaped conductor (34) extends into a microwave cavity (24) to receive microwaves passing in the cavity (24). These received microwaves are focused at the tip (33) to heat the gas into plasma. The microwave plasma nozzle (26) also includes a vortex guide (36) between the rod-shaped conductor (34) and the gas flow tube (40) imparting a helical shaped flow direction to the gas flowing through the tube (40). The microwave plasma nozzle (26) further includes a shielding mechanism (108) for reducing a microwave power loss through the gas flow tube (40).