A crystal growth doping apparatus and a crystal growth doping method are provided. The crystal growth doping apparatus includes a crystal growth furnace and a doping device that includes a feeding tube inserted to the furnace body along an oblique insertion direction, and a storage cover and a gate tube that are disposed in the feeding tube. The feeding tube extends from an outer surface thereof to form a placement opening, and the placement opening is recessed from an edge thereof to form an upper recessed portion and a lower recessed portion along the oblique insertion direction. The storage cover includes a storage tank and a handle. When the storage cover is disposed in the gate tube body, the gate tube body is configured to isolate an inner space of the feeding tube from the placement opening.

A crystal growth doping apparatus and a crystal growth doping method are provided. The crystal growth doping apparatus includes a crystal growth furnace and a doping device that includes a feeding tube inserted to the furnace body along an oblique insertion direction, and a storage cover and a gate tube that are disposed in the feeding tube. The feeding tube extends from an outer surface thereof to form a placement opening, and the placement opening is recessed from an edge thereof to form an upper recessed portion and a lower recessed portion along the oblique insertion direction. The storage cover includes a storage tank and a handle. When the storage cover is disposed in the gate tube body, the gate tube body is configured to isolate an inner space of the feeding tube from the placement opening.

A scintillation crystal can include Ln.sub.(1-y)RE.sub.yX.sub.3, wherein Ln represents a rare earth element, RE represents a different rare earth element, y has a value in a range of 0 to 1, and X represents a halogen. In an embodiment, RE is Ce, and the scintillation crystal is doped with Sr, Ba, or a mixture thereof at a concentration of at least approximately 0.0002 wt. %. In another embodiment, the scintillation crystal can have unexpectedly improved linearity and unexpectedly improved energy resolution properties. In a further embodiment, a radiation detection system can include the scintillation crystal, a photosensor, and an electronics device. Such a radiation detection system can be useful in a variety of radiation imaging applications.

A scintillation crystal can include Ln.sub.(1-y)RE.sub.yX.sub.3, wherein Ln represents a rare earth element, RE represents a different rare earth element, y has a value in a range of 0 to 1, and X represents a halogen. In an embodiment, RE is Ce, and the scintillation crystal is doped with Sr, Ba, or a mixture thereof at a concentration of at least approximately 0.0002 wt. %. In another embodiment, the scintillation crystal can have unexpectedly improved linearity and unexpectedly improved energy resolution properties. In a further embodiment, a radiation detection system can include the scintillation crystal, a photosensor, and an electronics device. Such a radiation detection system can be useful in a variety of radiation imaging applications.

A scintillation crystal can include Ln.sub.(1-y)RE.sub.yX.sub.3, wherein Ln represents a rare earth element, RE represents a different rare earth element, y has a value in a range of 0 to 1, and X represents a halogen. In an embodiment, RE is Ce, and the scintillation crystal is doped with Sr, Ba, or a mixture thereof at a concentration of at least approximately 0.0002 wt. %. In another embodiment, the scintillation crystal can have unexpectedly improved linearity and unexpectedly improved energy resolution properties. In a further embodiment, a radiation detection system can include the scintillation crystal, a photosensor, and an electronics device. Such a radiation detection system can be useful in a variety of radiation imaging applications.

A scintillation crystal can include Ln.sub.(1-y)RE.sub.yX.sub.3, wherein Ln represents a rare earth element, RE represents a different rare earth element, y has a value in a range of 0 to 1, and X represents a halogen. In an embodiment, RE is Ce, and the scintillation crystal is doped with Sr, Ba, or a mixture thereof at a concentration of at least approximately 0.0002 wt. %. In another embodiment, the scintillation crystal can have unexpectedly improved linearity and unexpectedly improved energy resolution properties. In a further embodiment, a radiation detection system can include the scintillation crystal, a photosensor, and an electronics device. Such a radiation detection system can be useful in a variety of radiation imaging applications.

A process for growing a substrate (24) as a melt pool (28) solidifies beneath a molten slag layer (30). An energy beam (36) is used to melt a powder (32) or a hollow feed wire (42) with a powdered alloy core (44) under the slag layer. The slag layer is at least partially transparent (37) to the energy beam, and it may be partially optically absorbent or translucent to the energy beam to absorb enough energy to remain molten. As with a conventional ESW process, the slag layer insulates the molten material and shields it from reaction with air. A composition of the powder may be changed across a solidification axis (A) of the resulting component (60) to provide a functionally graded directionally solidified product.

A process for growing a substrate (24) as a melt pool (28) solidifies beneath a molten slag layer (30). An energy beam (36) is used to melt a powder (32) or a hollow feed wire (42) with a powdered alloy core (44) under the slag layer. The slag layer is at least partially transparent (37) to the energy beam, and it may be partially optically absorbent or translucent to the energy beam to absorb enough energy to remain molten. As with a conventional ESW process, the slag layer insulates the molten material and shields it from reaction with air. A composition of the powder may be changed across a solidification axis (A) of the resulting component (60) to provide a functionally graded directionally solidified product.

The present invention relates to an orthogonal-phase compound and its nonlinear optical (NLO) crystal of BaGa.sub.7Se.sub.7, its producing method and uses thereof. Polycrystalline orthogonal-phase BaGa.sub.4Se.sub.7 was prepared by a high-temperature solid-phase reaction in a sealed silica tube. Large size single crystals of orthogonal-phase BaGa.sub.4Se.sub.7 could be prepared by the flux method or Bridgman method. BaGa.sub.4Se.sub.7 crystallizes in the point group mm2. Orthogonal-phase BaGa.sub.4Se.sub.7 has a powder second harmonic generation (SHG) efficiency of about 5 times that of AgGaS.sub.2 and is phase-matchable. The orthogonal-phase BaGa.sub.4Se.sub.7 is non-hygroscopic and has good mechanical properties, which makes it easy to cut, polish, and coat by normal processing. The orthogonal-phase BaGa.sub.4Se.sub.7 crystal has never been cracked during cutting and polishing. The orthogonal-phase compound and NLO crystal of BaGa.sub.4Se.sub.7 can be used as NLO devices.

The present invention relates to an orthogonal-phase compound and its nonlinear optical (NLO) crystal of BaGa.sub.7Se.sub.7, its producing method and uses thereof. Polycrystalline orthogonal-phase BaGa.sub.4Se.sub.7 was prepared by a high-temperature solid-phase reaction in a sealed silica tube. Large size single crystals of orthogonal-phase BaGa.sub.4Se.sub.7 could be prepared by the flux method or Bridgman method. BaGa.sub.4Se.sub.7 crystallizes in the point group mm2. Orthogonal-phase BaGa.sub.4Se.sub.7 has a powder second harmonic generation (SHG) efficiency of about 5 times that of AgGaS.sub.2 and is phase-matchable. The orthogonal-phase BaGa.sub.4Se.sub.7 is non-hygroscopic and has good mechanical properties, which makes it easy to cut, polish, and coat by normal processing. The orthogonal-phase BaGa.sub.4Se.sub.7 crystal has never been cracked during cutting and polishing. The orthogonal-phase compound and NLO crystal of BaGa.sub.4Se.sub.7 can be used as NLO devices.