Abstract: A scintillation detector includes a scintillation crystal directly coupled to a photomultiplier tube (PMT). The crystal/PMT subassembly is attached to a voltage divider and the entire device is hermetically sealed in a stainless steel outer case. Conductors are passed through the hermetic package from the voltage divider via a high temperature metal to ceramic pass-through. The crystal and PMT are longitudinally loaded within the outer case by springs in order to minimize vibrations in the crystal and PMT. A thermoplastic support sleeve circumscribes the crystal and the PMT to protect the crystal and PMT from excessive longitudinal loading. Preferably, the support sleeve and the crystal have similar coefficients of thermal expansion so that the crystal and the support sleeve experience similar dimensional changes due to temperature fluctuations, allowing the support sleeve to best maintain its stress-limiting function as temperature within the detector changes.

Abstract: An electronic circuit device package of the type having a metal laminate base flange of molybdenum clad with copper on both faces has a CVD diamond film substrate inlaid in a well in the bottom of the base flange so that it is flush with the base flange surface. An opening in the opposite side of the base flange forms a chamber with the diamond as a floor to which the device may be bonded in intimate contact with the diamond substrate. The edges of the diamond are brazed with a gold-indium braze in intimate thermal contact with a shoulder of the well to maximize heat conduction from the edges of the diamond into the base flange. The base flange may be fastened to the flat surface of a heat sink member with the diamond in intimate thermal contact with the heat sink member.

Abstract: This invention relates to a siliconized silicon carbide-base composite comprising at least about 71 vol % converted-graphite SiC matrix having open porosity, wherein the open porosity of the matrix is essentially filled with silicon, and the composite has a total metallic impurity content of no more than 10 ppm.

Abstract: Abrasive grain with increased projectability in a UP deposition process is provided with a first conductive coating and a second coating comprising a silicon-containing compound.

Abstract: An apparatus and methods for manufacturing curved scintillation crystal detector plates uses hot forging of crystal material. Crystal material is brought to a temperature between its plastic temperature and its melting temperature, and it is pressed between a pair of dies having curved pressing surfaces. The heated crystal material may be a freshly-drawn ingot of crystal material, and the method for producing curved plates may include cutting the hot-forged ingot into individual plates.

Abstract: An apparatus for depositing synthetic diamond on a surface of a substrate includes a deposition chamber and a cooling block having a surface in the deposition chamber that is cooled by heat exchange. The substrate is supported from the cooling block so that the bottom surface of the substrate is spaced from the cooling block surface by a gap, and a gas is provided in the deposition chamber and in the gap, the gas comprising at least 30 percent hydrogen gas. A plasma deposition system forms in the chamber a plasma containing hydrogen gas and a hydrocarbon gas for depositing synthetic diamond on the top surface of the substrate.

Abstract: Alkali halide crystal is grown from a melt in a novel graphite crucible which has a surface depth region of its inside surface impregnated with glassy carbon to eliminate porosity, so that the melt does not leak through or wet the carbon. Additionally, the graphite may be coated with glassy carbon to provide a smoother surface. Also disclosed is a porous graphite crucible lined with a layer of graphitic pyrolytic carbon to prevent wetting of the surface by the melt and to permit release of the cooled crystal without remelting.

Abstract: Sol-gel alumina that is dried but unfired can be explosively comminuted by feeding the dried gel into a furnace held at temperatures above those at which vaporizable materials are eliminated from the particles of gel. At suitably elevated temperatures the firing is sufficient to form fully densified alpha alumina particles of a size suitable for direct use as abrasive grits.

Abstract: An apparatus for depositing diamond film is disclosed, which comprises: a chamber; a reaction zone in the chamber; means for feeding diamond forming gases and an electron source gas into the reaction zone; means for applying an electric field across the reaction zone to accelerate free electrons of the electron source gas and dissociate hydrogen in the diamond forming gases to produce atomic hydrogen; and a deposition surface adjacent the reaction zone, whereby diamond film is deposited on the deposition surface from the diamond forming gases, assisted by the atomic hydrogen.

Abstract: An electrical connection for a ceramic hot surface element in which the ends of the hot surface element are essentially interference fit within a pair of metallic termination sleeves, and electrical connection to the hot surface element is provided by an active metal braze which is directly chemically bonded to the metallic termination.

Abstract: This invention relates to a support zone for a hairpin-style ceramic igniter, the support zone comprising AlN and SiC, and preferably alumina.

Abstract: Cryogenic sedimentation is effective to bring about the rapid separation of sub-micron particles from powder mixtures containing such particles without leading to significant agglomeration.

Abstract: A hydrogen torch comprising concentric inner and outer fluid delivery tubes, wherein;a) the outer tube comprises silica, andb) the inner tube comprises silicon carbide.

Abstract: This invention relates to the use of a continuously energized ceramic igniter in providing a "relight" function in stovetop cooking applications.

Abstract: An optical polishing slurry with alumina and ceria components is found to produce an improved polishing performance over either component used alone.

Abstract: The invention relates to a vertical rack for semiconductor wafer processing having strictly horizontally disposed arms wherein each arms has a rounded tip.

Abstract: Alkali halide crystal is grown from a melt in a novel graphite crucible which has a surface depth region of its inside surface impregnated with glassy carbon to eliminate porosity, so that the melt does not leak through or wet the carbon. Additionally, the graphite may be coated with glassy carbon to provide a smoother surface. Also disclosed is a porous graphite crucible lined with a layer of graphitic pyrolytic carbon to prevent wetting of the surface by the melt and to permit release of the cooled crystal without remelting.

Abstract: This invention relates to a sintered silicon nitride ceramic material comprising:a) at least 80 wt % silicon nitride grains, andb) between 0.1 and 5 wt % additive grains characterized by at least one of:i)a Knoop hardness of at least 25 GPa,ii) a coefficient of thermal expansion of at least 6.times.10.sup.-6 /K, andiii) a modulus of elasticity of at least 600 GPa,wherein the maximum detectable grain size of the additive grains is no more than 4 um, as determined by a photomicrograph of a polished 75 mm.sup.2 microstructure of the silicon nitride material.

Abstract: The present invention relates a ceramic igniter comprising:a) a pair of electrically conductive portions, each portion having a first end,b) a hot zone disposed between and in electrical connection with each of the first ends of the electrically conductive portions, the hot zone having an electrical path length of less than 0.5 cm, andc) an electrically non-conductive heat sink material contacting the hot zone.

Abstract: A process for coating a tungsten carbide base material substrate with CVD diamond film includes carburization and gas-assisted vaporization of cobalt from the surface with simultaneous recrystallization of surface grains of tungsten carbide to change their stoichiometry for improved adherence.Also disclosed is a WC-Co cutting tool having a relatively fine WC grain size and coated with adherent CVD diamond.