Abstract: An explosive detection system detects the presence of trace molecules in air. The sensitivity of such instruments is dependent on the concentration of target gas in the sample. The sampling efficiency can be greatly improved when the target object is warmed, even by only a few degrees. A directed emission of photons, typically infrared or visible light, can be used to significantly enhance vapor emission. The sensitivity of such instruments is also dependent on the method of gas sampling utilized. A cyclone sampling nozzle can greatly improve the sampling efficiency, particularly when the sampling needs to be performed at a distance from the air intake.

Abstract: The presence of trace molecules in air is often determined using a well-known device called an ion mobility spectrometer. Such devices are commonly utilized in the fields of explosives detection, identification of narcotics, and in applications characterized by the presence of very low airborne concentrations of organic molecules of special interest. The sensitivity of such instruments is dependent on the method of gas sampling utilized. The vortex sampling nozzle consists of an intake gas flow and a separate coaxial heated, emitted gas flow that is deflected to move with a circular motion. A heated vortex sampling nozzle can greatly improve the sampling efficiency for low volatility target molecules, particularly when the sampling needs to be performed at a distance from the air intake and the vapor pressure of the target molecule is very low.

Abstract: The presence of trace molecules in air may be determined using an ion mobility spectrometer. Such devices may be used in the fields of explosives detection, identification of narcotics, and in applications characterized by the presence of very low airborne concentrations of organic molecules of special interest. The sensitivity of such instruments may depend upon on the method of gas sampling utilized. A virtual wall gas sampling system can greatly improve the sampling efficiency, particularly when the sampling needs to be performed at a distance from the air intake and large volumes need to be sampled. The virtual wall gas sampling system consists of an intake gas flow and a separate group of one or more sheet-like gas flows, which may be either mutually deflected to move with a circular motion or may be formed into a cylindrical bounding surface.

Abstract: An explosive detection system detects the presence of trace molecules in air. The sensitivity of such instruments is dependent on the concentration of target gas in the sample. The sampling efficiency can be greatly improved when the target object is warmed, even by only a few degrees. A directed emission of photons, typically infrared or visible light, can be used to significantly enhance vapor emission. The sensitivity of such instruments is also dependent on the method of gas sampling utilized. A cyclone sampling nozzle can greatly improve the sampling efficiency, particularly when the sampling needs to be performed at a distance from the air intake.

Abstract: The presence of trace molecules in air is often determined using a well-known device called an ion mobility spectrometer. Such devices are commonly utilized in the fields of explosives detection, identification of narcotics, and in applications characterized by the presence of very low airborne concentrations of organic molecules of special interest. The sensitivity of such instruments is dependent on the concentration of target gas in the sample. The sampling efficiency can be greatly improved when the target object is warmed, even by only a few degrees. A directed emission of photons, typically infrared or visible light, can be used to significantly enhance vapor emission.

Abstract: The presence of trace molecules in air may be determined using an ion mobility spectrometer. Such devices may be used in the fields of explosives detection, identification of narcotics, and in applications characterized by the presence of very low airborne concentrations of organic molecules of special interest. The sensitivity of such instruments is dependent on the method of gas sampling utilized. A cyclone sampling nozzle can greatly improve the sampling efficiency, particularly when the sampling needs to be performed at a distance from the air intake. The cyclone sampling nozzle consists of an intake gas flow and a separate coaxial emitted gas flow which is deflected to move with a circular motion.

Abstract: The present invention comprises methods for producing semiconductor devices useful in high temperature applications. The invention is based on using silicon ion implantation to convert a portion of the p-type base layer of magnesium-doped GaN into n-type GaN. The boundary of the n-type GaN within the p-type layer then becomes an n-p diode junction which can function as the emitter-base junction. The present methods utilize ion implantation to convert a portion of the p-type layer to n-type thereby forming an n-p junction having desirable diode characteristics. The invention also includes BJT and HBT devices incorporating the present implanted n-p diode junctions.

Abstract: An implantable medical device according to the present invention comprises a body, such as a stent or a wire, having a radioisotope or non-radioactive precursor isotope associated with the body. The isotope preferably is disposed on the body using an efficient deposition method, such as an effusion cell. The method reduces the waste of costly isotopes and reduces the buildup of hazardous material in the apparatus. A metal layer may be deposited simultaneously with or subsequent to deposition of the isotope to encapsulate the radioactive isotope.

Abstract: An implantable medical device according to the systems and methods described herein may include a metal body or stent that does not contain significant quantities of iron or chromium and that is initially formed from a non-radioactive structural material. A non-radioactive activatable additive (the precursor isotope) may be added into or onto the body of the medical device. Neutron activation of the body of the medical device with the incorporated non-radioactive isotope may then be accomplished, and, if the metal body of the medical device contains a significant quantity of nickel, a coating of a high-density material may be applied over the radioactive body of the medical device. In an alternate embodiment, a coating of certain types of high-density material may be applied prior to neutron activation.

Abstract: An improved coated orthopaedic implant component is disclosed. The implant may be coated with platinum, iridium or other metals for improved characteristics. Ion beam coating orthopaedic parts by ion implanting the parts with zirconium ions while the parts are immersed in an oxygen-containing background gas is also disclosed. The adhesion of the graded interface zirconium oxide surface layer so formed is further improved by the initial removal of surface contamination using an ion bombardment and the deposition of an intermediate layer of platinum or similar metal or silicon between the orthopaedic metal component and the zirconium oxide. Furnace heating results in atomic interdiffusion to enhance adhesion between the surfaces. The zirconium oxide provides a low friction, low wear articulating surface. The graded interface may be characterized by a blackish color and a transition between pure zirconium oxide and pure intermediate layer that extends over a thickness of hundreds of Angstroms.

Abstract: An ion source is described for use with conventional and modified ion implantation equipment to improve safety and increase efficiency when generating radioactive ion beams. The ion source is particularly useful with radioactive species that are volatile at room temperature or react with air molecules to form volatile compounds. One or more components of the ion source, such as a cathode, an anode, an electrostatic electron reflector, a vaporizer, a sputter target, a gas line or a plasma chamber, may be mounted on extensible probes within radiation shielded sealable transfer containers. Other components of the ion source may be fixed in a vacuum chamber, which may have one or more valved openings corresponding to the sealable openings in the transfer containers. The components on the probes may be extended into position inside the vacuum chamber for operation of the ion source, and may be retracted into the sealable transfer containers and transported to an area for servicing or repair.

Abstract: A method is disclosed for ion beam treating orthopaedic parts by ion implanting the parts with aluminum ions while the parts are immersed in an oxygen-containing background gas. When the parts are at sufficiently elevated temperature, a highly adherent layer of aluminum oxide is grown which provides a low friction, low wear articulating surface. The interface between the semi-pure aluminum oxide and the substrate orthopaedic part consists of a composition which gradually grades with depth between the grown aluminum oxide and the pure substrate material. This interface has a thickness dependent on the processing parameters, typically hundreds of Angstroms. In an alternative embodiment, the thickness of the alumina layer may be increased by simultaneously depositing aluminum oxide on the parts.

Abstract: According to the present invention, an ion beam flux measurement device may include an exposure area, a measuring area disposed a predetermined distance from the exposure area, a moveable target having at least a portion thereof disposed within the exposure area, an actuator coupled to the target, and a radioactive emission detector disposed within the measuring area. The radioactive emission detector also may include a viewing portion and may detect beta rays or gamma rays. The actuator may include a feed roller and a take up roller. The target preferably may include a foil coupled to and extending between the rollers. The foil may be continuously moveable between the rollers or may be moveable in a stepwise manner. The ion beam flux measurement device also may include a collimator, preferably including a high density material when beta rays are to be detected, coupled to the radioactive emission detector. A secondary liner may be coupled to the collimator.

Abstract: An improved coated orthopaedic implant component is disclosed. The implant may be coated with platinum for improved characteristics. Ion beam coating orthopaedic parts by ion implanting the parts with zirconium ions while the parts are immersed in an oxygen-containing background gas is also disclosed. The adhesion of the graded interface zirconium oxide surface layer so formed is further improved by the initial removal of surface contamination using an ion bombardment and the deposition of an intermediate layer of platinum or silicon between the orthopaedic metal component and the zirconium oxide. Furnace heating results in atomic interdiffusion to enhance adhesion between the surfaces. The zirconium oxide provides a low friction, low wear articulating surface. The graded interface may be characterized by a blackish color and a transition between pure zirconium oxide and pure intermediate layer that extends over a thickness of hundreds of Angstroms.

Abstract: A method is disclosed for ion beam coating orthopaedic parts by ion implanting the parts with zirconium ions while the parts are immersed in an oxygen-containing background gas. A highly adherent surface layer of zirconium oxide is formed which provides a low friction, low wear graded interface for the articulating surface. The graded interface is characterized by a blackish color and a transition between pure zirconia and pure substrate material that extends over a thickness of hundreds of Angstroms. In an alternative embodiment, the thickness of the zirconia coating may be increased by also adding a simultaneous evaporation of zirconium metal on the parts.

Abstract: A method of epitaxially growing a surface layer on a substrate including the steps of coating the substrate surface, with a meltable film, melting the film and implanting ions into he melted film, to deposit ion material onto the coated substrate surface.

Abstract: A method and an apparatus for the ion implantation of spherical surfaces are disclosed. The method essentially includes the provision of a fixture by which a plurality of spherical workpieces are presented to a large area ion beam in a way that their entire respective spherical surfaces are uniformly ion implanted to improve their surface characteristics. The fixture basically includes a solid disc mounted for motion about two axes normal to each other, a plurality of cages formed in a first surface of the disc loosely to accommodate therein a plurality of spherical workpieces, cooling means disposed on a second surface of the disc, and a cover plate and/or mask mounted on the first surface of the disc and provided with a plurality of apertures concentric with the plurality of cages formed in the disc.