11 results about "Gadolinium oxysulfide" patented technology

The invention relates to a preparation method of a terbium-doped gadolinium oxysulfide fluorescent material. The performance of the material is remarkably improved through an optimized high-temperature solid-phase method. According to the process, firstly, polyvinylpyrrolidone (PVP) and dopamine hydrochloride are used as a dispersing agent and a coating agent to prepare uniformly dispersed Gd2O3 and Tb4O7 oxide precursors, then through a fluxing agent system with the synergistic effect of boric acid and lithium carbonate and in combination with a low-temperature pre-sintering-medium-temperature vulcanization-high-temperature crystallization three-stage sintering process, grain aggregation and abnormal growth are effectively inhibited, and the Gd2O3 / Tb4O7 composite material is obtained. And finally, annealing in air to remove carbon impurities to obtain the superfine fluorescent powder with small particle size and narrow distribution. Experiments show that the particle size D50 of the fluorescent powder in the embodiment is 496-678 nm, the fluorescence decay life exceeds 1100 microseconds, the luminous intensity is high, the stability is excellent, and the fluorescent powder has wide application prospects in the fields of liquid crystal display, biomedicine and the like.

A ceramic scintillator according to an embodiment of the present invention is provided with a sintered body of a gadolinium oxysulfide phosphor containing praseodymium as a main activator. When the body color of the sintered body is represented by chromaticity coordinates (x, y) based on a CIE1931 chromaticity value, the sintered body has a body color satisfying the following formulae (1) and (2). A ceramic scintillator according to an embodiment is obtained by a method for producing a ceramic scintillator, the method comprising a heat treatment step for reacting a reactant gas containing oxygen and sulfur with the sintered body. The heat treatment time in the heat treatment step is from 1 hour to 50 hours (inclusive). 0.4 < = x < = 0.505 (1) 0.83 x + 0.075 < = y < = 0.83 x + 0.095 (2).

A ceramic scintillator of an embodiment includes a sintered body of a gadolinium oxysulfide phosphor containing praseodymium as a main activator. When a body color of the sintered body is represented by chromaticity coordinates (x, y) based on a CIE1931 chromaticity value, the sintered body has a body color satisfying 0.4≤x≤0.505 . . . (1) and 0.83x+0.075≤y≤0.83x+0.095 . . . (2). The ceramic scintillator of the embodiment is obtained by a method for manufacturing a ceramic scintillator, the method including a heat treatment step of causing a reaction gas containing oxygen and sulfur to react with the sintered body. A heat treatment time in the heat treatment step is 1 hour or more and 50 hours or less.

The invention relates to the technical field of scintillation screens, in particular to a scintillation screen based on gadolinium gallium aluminum garnet scintillation single crystals and a preparation method of the scintillation screen. The scintillation screen comprises a substrate, a light reflecting layer, a gadolinium gallium aluminum garnet scintillator powder screen and a light emitting layer, an inner groove is formed in the upper surface of the reflective layer, and the gadolinium gallium aluminum garnet scintillator powder screen is arranged in the inner groove; the gadolinium-gallium-aluminum garnet scintillator powder screen is prepared by mixing gadolinium-gallium-aluminum garnet scintillation single crystal particles and an inorganic binder in proportion, sintering and then grinding and polishing. The problems that an existing needle-shaped cesium iodide scintillation screen is not resistant to irradiation, prone to deliquescence and poor in afterglow, a gadolinium oxysulfide ceramic scintillation screen is poor in resolution ratio and low in luminous efficiency, and a Ce: GAGG single crystal spliced scintillation screen has a dead zone are solved, the irradiation stability and environmental adaptability of the scintillation screen are remarkably improved, the service life of the scintillation screen is remarkably prolonged, meanwhile, the preparation process is flexible, and the cost is low. And high-performance scintillation screens with different shapes and sizes can be prepared.

A scintillator screen for use in backscatter and transmission X-ray detectors is provided. The scintillator screen includes at least a phosphor layer comprising a plurality of phosphor particles preferably having a mean particle size ranging from 30 μm to 70 μm, and preferably from 30 μm to 50 μm. Alternatively, each of the plurality of phosphor particles has a particle size in a range of 30 μm to 70 μm, and preferably from 30 μm to 50 μm. A thickness of the scintillator layer ranges from 100 μm to 4000 μm while packing fraction of phosphor weight to total weight of phosphor and a binder ranges from 50% to 90%. The phosphor layer preferably includes europium-doped barium fluorochloride (BaFCl:Eu) for use in a backscatter X-ray detector and preferably includes Gadolinium Oxysulfide (Gd2O2S) for use in a transmission X-ray detector.

A scintillator screen for use in backscatter and transmission X-ray detectors is provided. The scintillator screen includes at least a phosphor layer comprising a plurality of phosphor particles preferably having a mean particle size ranging from 30 µm to 70 µm, and preferably from 30 µm to 50 µm. Alternatively, each of the plurality of phosphor particles has a particle size in a range of 30 µm to 70 µm, and preferably from 30 µm to 50 µm. A thickness of the scintillator layer ranges from 100 µm to 4000 µm while packing fraction of phosphor weight to total weight of phosphor and a binder ranges from 50% to 90%. The phosphor layer preferably includes europium-doped barium fluorochloride (BaFCLEu) for use in a backscatter X-ray detector and preferably includes Gadolinium Oxysulfide (Gd2O2S) for use in a transmission X-ray detector.

This invention relates to a method for fabricating a gadolinium oxysulfate X-ray scintillation screen based on a silicon microchannel array, as well as the X-ray scintillation screen and its applications, belonging to the field of X-ray imaging technology. It primarily addresses the technical problem of low resolution in existing X-ray scintillation screens. This invention fabricates a tetragonal silicon microchannel structure through photolithography, photoelectrochemical etching, and back-side thinning processes, fundamentally avoiding the problem of microchannel misalignment. The use of ALD tungsten film deposition and pulse electroplating for silver film deposition effectively reduces X-ray crosstalk. Furthermore, the good chemical compatibility between tungsten and silver ensures uniform silver film deposition without microchannel blockage, and the silver film possesses high reflectivity. Vacuum infusion is used to completely fill the microchannels with fluorescent material, avoiding the presence of air or other substances with significantly different refractive indices from the fluorescent material within the channels, and also solving the scattering and reflection problems caused by gaps between particles, effectively improving detection efficiency.

The application belongs to the technical field of ceramics and refrigeration, and particularly relates to gadolinium oxysulfide cold storage ceramic microspheres, a preparation method thereof and application thereof. GOS ceramic powder, acrylic acid photocuring resin and anhydrous ethanol are mixed in proportion, and a plastic body is obtained through calendering; the plastic body is extruded from a die extrusion port to form a wire rod, and the wire rod is cured through ultraviolet light to obtain a GOS cured wire rod; the GOS cured wire rod is cut into microcylinders, dried, and spheroidized through radio frequency plasma to obtain GOS cold storage microspheres with uniform particle size distribution. The microspheres obtained through the method have regular shapes, highly uniform particle sizes and high densities, and when used as cold storage fillers of a two-stage G-M cryogenic refrigerator two-stage cold end heat exchanger, the microspheres can improve refrigeration efficiency and temperature stability, meet the demand of high-precision low-temperature scenes, have good process reproducibility, and are beneficial to industrialized production.

A cryocooler cold head regenerator having a series of discrete sections formed from particles of tin-antimony, particles of holmium copper, particles of gadolinium oxysulfide, and particles of gadolinium aluminate. Each section is separated from an adjoining section by a multi-layer screen formed from a stacked layers of copper mesh, felt, phosphor bronze mesh, and brass mesh. A cryocooler outfitted with regenerator can have an increased heat capacity to achieve temperatures in the cold head below 2.3 K with optimized heat lift at 3 K.

The invention belongs to the technical field of ceramics and refrigeration, and particularly relates to gadolinium oxysulfide cold storage ceramic microspheres as well as a preparation method and application thereof. The preparation method comprises the following steps: mixing GOS ceramic powder, acrylic light-cured resin and absolute ethyl alcohol in proportion, and calendering to obtain a plastic material body; the GOS is extruded from an extrusion opening of the die to form a wire rod, and the wire rod is cured by ultraviolet light to obtain a GOS cured wire rod; and cutting into micro-cylinders, drying, and spheroidizing by radio frequency plasma to obtain the GOS cold storage microspheres with uniform particle size distribution. The microspheres prepared through the method are regular in sphericity, uniform in particle size height and high in density, when the microspheres are used as cold storage filler of a two-stage cold end heat exchanger of a two-stage G-M low-temperature refrigerator, the refrigeration efficiency and the temperature stability can be improved, the high-precision low-temperature scene requirement is met, the process reproducibility is good, and industrial production is facilitated.

The application relates to a preparation method of a terbium-doped gadolinium oxysulfide fluorescent material, and the material performance is remarkably improved through an optimized high-temperature solid-phase method. The process is characterized in that: firstly, polyvinylpyrrolidone (PVP) and dopamine hydrochloride are used as dispersants and coating agents to prepare Gd2O3 and Tb4O7 oxide precursors which are uniformly dispersed; then, a fluxing agent system of boric acid and lithium carbonate is used in cooperation, and a three-stage sintering process of "low-temperature pre-sintering-middle-temperature sulfuration-high-temperature crystallization" is combined to effectively inhibit grain agglomeration and abnormal growth; finally, carbon impurities are removed through air annealing to obtain superfine fluorescent powder with small particle size and narrow distribution. Experiments show that the fluorescent powder in the examples has a particle size D50 of 496-678 nm, a fluorescent decay lifetime of more than 1100 mu s, high luminous intensity and excellent stability, and has a wide application prospect in the fields of liquid crystal display, biomedicine and the like.