Abstract:
Plasma-assisted methods and apparatus that use multiple radiation sources are provided. In one embodiment, a plasma is ignited by subjecting a gas in a radiation cavity to electromagnetic radiation having a frequency less than about 333 GHz in the presence of a plasma catalyst, which may be passive or active. A controller can be used to delay activation of one radiation source with respect to another radiation source.
Abstract:
Methods and apparatus are provided for plasma-assisted gas production. In one embodiment, a gas, which includes at least one atomic or molecular species, can flow into a cavity (305). The gas can be subjected to electromagnetic radiation having a frequency less than about 333 GHz (optionally in the presence of a plasma catalyst) such that a plasma (310) forms in the cavity (305). A filter (315) capable of passing the atomic or molecular species, but preventing others from passing, can be in fluid communication with the cavity (305). In this way, the selected species can be extracted and collected, for storage or immediate use.
Abstract:
Methods and apparatus are provided for igniting, modulating, and sustaining a plasma for synthesizing carbon structures. In one embodiment, a method is provided for synthesizing a carbon structure including forming a plasma by subjecting a gas to electromagnetic radiation in the presence of a plasma catalyst and adding at least one carbonaceous material to the plasma to grow the carbon structures on a substrate. Various types of plasma catalysts are also provided.
Abstract:
Methods and apparatus are provided for igniting, modulating, and sustaining a plasma for at least partially decrystallizing a surface of an object. In one embodiment, a method is provided for decrystallizing a surface of an object by forming a plasma (such as by subjecting a gas to an amount of electromagnetic radiation, optionally in the presence of a plasma catalyst) and exposing the surface of the object to the plasma.
Abstract:
Apparatus and methods for plasma-assisted melting are provided. In one embodiment, a plasma-assisted melting method can include: (1) adding a solid to a melting region, (2) forming a plasma in a cavity by subjecting a gas to electromagnetic radiation having a frequency less than about 333 GHz in the presence of a plasma catalyst, wherein the cavity has a wall, (3) sustaining the plasma in the cavity such that energy from the plasma passes through the wall into the melting region and melts the solid into a liquid, and (4) collecting the liquid. Solids that can be melted consistent with this invention can include metals, such as metal ore and scrap metal. Various plasma catalysts are also provided.
Abstract:
Methods and apparatus are provided for igniting, modulating, and sustaining a plasma for various plasma processes and treatments. Such treatments include cleaning and sterilizing parts. In some embodiments, a plasma is ignited by subjecting a gas in a multi-mode processing cavity to electromagnetic radiation having a frequency between about 1 MHz and about 333 GHz in the presence of a plasma catalyst. A part can be cleaned by, for example, inserting hydrogen into the plasma and exposing the part to the hydrogen-enriched plasma. A part can be sterilized by heating the part with the plasma.
Abstract:
Methods and apparatus are provided for igniting, modulating, and sustaining a plasma (615) for coating objects (250). In one embodiment, a method of coating a surface of an object (250) includes forming a plasma (615) in a cavity (230) by subjecting a gas to electromagnetic radiation in the presence of a plasma catalyst (240) and adding at least one coating material (510) to the plasma (615) by energizing the material (510) with, for example, a laser (500). The material (510) is allowed to deposit on the surface of the object (250) to form a coating. Various types of plasma (240) catalysts are also provided.
Abstract:
Methods and apparatus are provided for igniting, modulating, and sustaining a plasma for various doping processes. In one embodiment, a substrate (250) can be doped by forming a plasma (610) in a cavity (285) by subjecting a gas to an amount of electromagnetic radiation in the presence of a plasma catalyst (240) and adding at least one dopant material to the plasma. The material is then allowed to penetrate into the substrate. Various active and passive catalysts are provided.
Abstract:
Methods and apparatus for plasma-assisted joining of one or more parts together are provided. The joining process may include, for example, placing at least first and second joining areas in proximity to one another in a cavity, forming a plasma in the cavity by subjecting a gas to electromagnetic radiation in the presence of a plasma catalyst, and sustaining the plasma at least until the first and second joining areas are joined. Plasma catalysts, and methods and apparatus for igniting, modulating, and sustaining a joining plasma, are provided. Additional cavity shapes, and methods and apparatus for selective plasma-joining, are also provided.
Abstract:
A method and apparatus are provided for treating the surface of a metal body through phase transformation, ion implantation, and/or diffusion and to form new phases of metallic materials. The method and apparatus have been shown to be particularly useful to improve the hardness and corrosion resistance of ferrous and non-ferrous metals. Generally, the method comprises irradiating a portion of the metal body (18) with a laser (12), and directing a stream of gas (22) onto the same portion of the metal body simultaneously with and preferably for a duration after the laser is turned off. Preferably, the laser (12) is a carbon dioxide laser operated in a pulsed mode to control heating of the metal (18). The gas (22) is preferably carbon dioxide to quickly cool the metal when the laser is off, and to provide carbon atoms for deposition onto the body. The entire process may be carried out in an environment at atmospheric pressure, obviating the need for a vacuum chamber or pressure controlled furnace or similar apparatus. After treatment, the hardness and corrosion resistance of at least a ferrous body are dramatically increased. Advantageously, both sides of a thin metal body, such as a metal tube, may be simultaneously treated. Further, a new, highly oxygenated, hard and extremely corrosion resistant metal phase may be created.