Abstract: Strike-over in an RF plasma gun is eliminated by interposing a grounded isolation device between the plasma jet and the RF coil which supplies energy to the plasma. The isolation device comprises a plurality of separated segments spaced apart in a circumferential direction and electrically connected together at one end and to ground potential. The shield substantially eliminates the parasitic distributed capacitance between the RF coil and the plasma by interrupting the electrical field coupling between the coil and the plasma and shunting most of the capacitive current flow to ground. The invention enables reliable operation of the device at frequencies in the 2-4 MHz range.

Abstract: Apparatus and method for an RF plasma gun with injection probe that imparts feed material with a controllable radial component of motion by providing a conical exit port for the injection probe or a mesh screen therein.

Abstract: Apparatus and a method for generating an RF plasma plume wherein hydrogen gas is introduced downstream of the means for injecting plasma gas in order to increase the coupling between the RF coil and the plume and to decrease heat loss to the plasma containment walls.

Abstract: A low frequency RF plasma spray deposition method is provided, which is especially effective in reducing losses and improving particle heating. In one aspect of the invention, an RF plasma gun is operated in the frequency range below 1 MHz and an argon-helium mixture to which a third component, such as hydrogen, can also be admixed, is substituted for the standard argon-hydrogen mixture used at frequencies above 2 MHz. In another aspect of the invention, a RF plasma gun is operated in the frequency range of 400-500 kHz and specific start up and operating procedures and conditions are set forth for successful deposition of titanium and refractory metal alloys.

Abstract: Apparatus and a method for generating an RF plasma plume wherein hydrogen gas is introduced downstream of the means for injecting plasma gas in order to increase the coupling between the RF coil and the plume and to decrease heat loss to the plasma containment walls.

Abstract: An RF plasma gun has a metal annular support ring at the gun's nozzle exit port. The ring is conductively mounted to a metal tank containing a substrate to be processed. The substrate is connected to a manipulator which is electrically isolated from the tank. A DC voltage is impressed between the tank, which contains an inert atmosphere at a pressure below that of ambient atmosphere, and the manipulator. The tank is placed at ground potential and the manipulator at a negative potential relative to the tank. The DC voltage creates an electric arc which flows from the exit port ring via the plasma to the substrate for cleaning the substrate.

Abstract: A vacuum interrupter includes an evacuated envelope and a pair of facing contacts situated therein. The contacts are relatively movable along a first axis from an engaged position to a disengaged position. Conductors extending through the envelope are provided for connecting the contacts to an external circuit. A pair of magnetic field coils are disposed on opposite sides of the contacts and connected in series therewith for establishing an axial magnetic field in the space between the contacts when the contacts are in the disengaged position.

Abstract: An exothermically assisted electric fuse, having at least one exothermic body disposed in heat transfer relationship with at least a portion of each fusible element of the fuse, a triggering circuit for initiating an exothermic reaction in response to an overcurrent through the fuse, and a containment body partially enclosing the exothermic body for directing the heat energy released by the exothermic reaction. The containment body is disposed so as to confine and direct the heat energy in a direction which is substantially perpendicular to a plane containing the portion of the fusible element which is in heat transfer relationship with the exothermic body. In a preferred embodiment of such a fuse, the fusible element is wound around a support so that the fuse windings form the general shape of a cylinder, and the containment body is disposed so that the heat energy is directed in a radial direction with respect to the cylinder formed by the fuse windings.

Abstract: Improvement of the peak current interruption performance of a vacuum interrupter is obtained by configuring the conductive leads to the vacuum interrupter in a manner whereby the magnetic field generated by current in the conductive leads and impinging upon the space between a pair of contacts of the vacuum interrupter is minimized, thereby resulting in better performance of the vacuum interrupter.

Abstract: The contacts and nozzle of a fluid blast circuit breaker are constructed to have a cross section with a shape other than circular or square. Such cross section facilitates providing the fluid for extinguishing an arc in a circuit breaker at a velocity perpendicular to the arc greater than the fluid velocity in a circular or square configuration nozzle having the same cross sectional area. Such high velocity fluid flow facilitates interrupting the arc by increasing the cooling rate of fluid flow past the arc.

Abstract: A current limiting fuse is disclosed wherein at least one fuse element is employed and each such fuse element is positioned in a narrow space filled with dielectric fluid adjacent a rigid electrically insulating member with a plurality of rupturable vents and a chamber on the opposite side of the member. The narrow space filled with dielectric fluid defines the arc constrictor while the chamber on the side of the member defines the plasma cooler space.