Abstract: Reactive gas is released through a crystal source material or melt to react with impurities and carry the impurities away as gaseous products or as precipitates or in light or heavy form. The gaseous products are removed by vacuum and the heavy products fall to the bottom of the melt. Light products rise to the top of the melt. After purifying, dopants are added to the melt. The melt moves away from the heater and the crystal is formed. Subsequent heating zones re-melt and refine the crystal, and a dopant is added in a final heating zone. The crystal is divided, and divided portions of the crystal are re-heated for heat treating and annealing.

Abstract: Crystal grower and purification stations immersed within crystal growing furnaces have preparation chambers with circular, elliptical, rectangular or polygonal cross-sections. A lateral heater and a base heater are connected for immersion mounting within the preparation chamber. A porous distributor is mounted above the base heater for immersion within the chamber. An opening or openings in a bottom of the chamber releases crystal material to a crucible or crucibles. A lid mounted on the chamber closes the chamber and forms an enclosed chamber with a closed environment. A crystal material supply, a dopant supply and a reduced pressure exhaust line are connected to the chamber. A purification substance supply is connected to the chamber with fluid purification substances supplied to the porous distributor. An external heater surrounds the chamber for heating the chamber and its contents. Insulation surrounds the external heater. An enclosure surrounds the insulation.

Abstract: For producing ultra pure materials a first station has a porous gas distributor. A material supply supplies material to the porous gas distributor. A gas source supplies gas to the distributor and through the distributor to the material in contact with the distributor. A heater adjacent the porous gas distributor heats and melts the material as gas is passed through the material. Dopant and a treatment liquid is or solid supplied to the material. Treated material is discharged from the first station into a second station. A second porous gas distributor in the second station distributes gas through the material in the second station. A crucible receives molten material from the second station for casting, crystal growing in the crucible or for refilling other casting or crystal growth crucibles. The material and the porous gas distributor move with respect to each other. One porous gas distributor is cylindrical and is tipped.

Abstract: Reactive gas is released through a crystal source material or melt to react with impurities and carry the impurities away as gaseous products or as precipitates or in light or heavy form. The gaseous products are removed by vacuum and the heavy products fall to the bottom of the melt. Light products rise to the top of the melt. After purifying, dopants are added to the melt. The melt moves away from the heater and the crystal is formed. Subsequent heating zones re-melt and refine the crystal, and a dopant is added in a final heating zone. The crystal is divided, and divided portions of the crystal are re-heated for heat treating and annealing.

Abstract: Reactive gas is released through a crystal source material or melt to react with impurities and carry the impurities away as gaseous products or as precipitates or in light or heavy form. The gaseous products are removed by vacuum and the heavy products fall to the bottom of the melt. Light products rise to the top of the melt. After purifying, dopants are added to the melt. The melt moves away from the heater and the crystal is formed. Subsequent heating zones re-melt and refine the crystal, and a dopant is added in a final heating zone. The crystal is divided, and divided portions of the crystal are re-heated for heat treating and annealing.

Abstract: A crystal plate 1 is grown in a continuous process by first purifying a crystal source material, a crystal melt or powder, in a purification station 3. Valves 7 control the flow of purified crystal melt or source powder 9 to a first hot zone 11, whose temperature is above the melt temperature of the crystal. A dopant source 17 with controller 19 provides dopant to the liquefied crystal 15. The first heater zone 21 surrounding the first hot zone 11 heats the crystal above its melting temperature. The second heater zone 27 produces a temperature in the second zone which is below the melt temperature of the crystal. The liquefied crystal, the liquid solid interface and the first portion of the crystal are supported in a boat-shaped crucible container with a bottom 31 and side walls. As the crystal leaves the support plate 31 it passes on to a conveyor 33. The crystal moves within an enclosure 43, which has a noble gas or noble gas and reactant gas atmosphere 45.

Abstract: Reactive gas is released through a crystal source material or melt to react with impurities and carry the impurities away as gaseous products or as precipitates or in light or heavy form. The gaseous products are removed by vacuum and the heavy products fall to the bottom of the melt. Light products rise to the top of the melt. After purifying, dopants are added to the melt. The melt moves away from the heater and the crystal is formed. Subsequent heating zones re-melt and refine the crystal, and a dopant is added in a final heating zone. The crystal is divided, and divided portions of the crystal are re-heated for heat treating and annealing.

Abstract: The crystals are sealed by either glass-to-metal seals or epoxy to prevent moisture degradation. Combined with the multiple moisture barriers, the new configurations are long lasting and provide long life for the modular detectors. The crystal geometry depends on the application. The crystal surfaces are shaped in such a way that provide minimum optical paths of the light photons. The cladding layers and the mirror system provide gas-free, high reflectivity crystal mirror surfaces. The mirrors can be specular or diffusive. Curved shapes at the photo detector sides provide the first step in focusing the light. Focused photon beams are easily translated into smaller photodetectors that have higher signal-to-noise ratio, are more compact in nature, are more economical. Crystals have upper and lower truncated conical or pyramidal portions and intermediate straight wall portions. The crystals have rounded bottoms and tops, and cladding on the crystals and mirrors on the cladding or on interior walls of a housing.

Abstract: A modular gamma camera plate assembly has a mirror peripherally supported in an encircling housing. The holder is connected to the mirror and to the housing. A thin glass plate is mounted beneath the crystal and extends outward and is connected to the housing. A thin mirror extends above the crystal and is connected peripherally to the housing. The thin glass plate assembly and the mirror are sealed to the housing and pockets with desiccant are provided to prevent ingress of moisture and to getter moisture from the housing and assembly.

Abstract: A well logging scintillation detector has a gamma ray detector crystal with a window at one end and a single or multi-layer cladding surrounding the remainder of the crystal, with a reflective layer surrounding the cladding. The reflective layer, which may be a thin, high reflective metallic layer or reflective particles in a resin matrix, is surrounded by an elastomer with reflective particles which is surrounded by a casing which is a metal. The casing is surrounded by one or more outer casings, which are separated from each other by elastomeric members. A resilient base is formed opposite the window. The window has a flat glass plate connected to the crystal with an optical coupler, and a clear elastomer optically coupled to the plate. A larger plate is optically coupled to the elastomer, and the larger plate is sealed to one or more of the outer casings by inter-fitted corrugated rings of glass and metal which entrap epoxy, which fills the corrugations.

Abstract: This invention relates to a fabrication of a gamma camera plate assembly that has long life and improved efficiency. Cladding and reflecting layers provide improvements in crystal output. Seals prevent moisture leaks, prolonging lifetime. Multi-barrier epoxy-filled seals and desiccant-filled recesses, elastomer-filled spaces and an extra optical coupling layer provide prolonged life and improved efficiency. Exterior rings with new glass-to-metal seals and metal-to-metal seals provide strong watertight assemblies. The gamma camera plate includes a crystal having an optical cladding and a reflector surrounding the cladding. A glass mounting plate is connected to one flat surface of the crystal by an optical coupler. A mounting ring surrounds the crystal and an outer surface of the glass plate. Barriers are formed in upper and lower surfaces of the mounting ring, and complementary barriers are formed in engaging surfaces of the glass plate and of the gamma ray window plate.