Abstract: [Problems to be Solved] A neutron scintillator excellent in neutron detection efficiency and n/? discrimination ability, and a neutron detector using the neutron scintillator are provided. [Means to Solve the Problems] A neutron scintillator comprising a eutectic body composed of laminar lithium fluoride crystals and laminar calcium fluoride crystals alternately arranged in layers, the thickness of the lithium fluoride crystal layers in the eutectic body being 0.1 to 5 ?m; or a neutron scintillator comprising a eutectic body composed of laminar lithium fluoride crystals and laminar calcium fluoride crystals alternately arranged in layers, the calcium fluoride crystal layers in the eutectic body being linearly continuous in at least one direction; and a neutron detector basically constructed from any of the neutron scintillators and a photodetector.

Abstract: A novel scintillator for neutron detection is capable of increasing the probability of inducing a nuclear reaction using epithermal neutrons having higher energy than thermal neutrons as a result of increasing thickness in the direction of incidence of neutron radiation. A scintillator for neutron detection includes a colquiriite-type fluoride single crystal containing europium, containing 0.0025 mol % or more and less than 0.05 mol % europium, containing 0.80 atom/nm3 or more 6Li, and being shaped such that the thickness in the thickest part exceeds 1 mm.

Abstract: The present invention is a neutron detection device comprising a neutron detection scintillator composed of a colquiriite-type fluoride single crystal, and a silicon photodiode, characterized in that the single crystal contains only Eu as a lanthanoid and contains 0.80 atom/nm3 or more of 6Li, the content of Eu is 0.0025 to 0.05 mol %, and the thickness of the scintillator exceeds 1 mm. The present invention provides a neutron detection device which has a sufficiently high neutron detection efficiency, is equipped with a neutron detection unit minimally affected by gamma rays, and is compact as a whole and lightweight.

Abstract: A neutron radiation detector has a function that discriminates between neutron radiation and ? radiation based on a difference in pulse shape between photodetection signals from a neutron radiation detection scintillator, which includes a Ce-containing LiCaAlF6 single crystal.

Abstract: [Problems to be Solved] A phoswich radiation detector, which can easily discriminate between detection signals on gamma rays and thermal neutrons, and which can selectively acquire signals on thermal neutrons, is provided. [Means to Solve the Problems] In a phoswich radiation detector having two scintillators and discriminating between thermal neutrons and gamma rays, the detector comprises a scintillator for detecting thermal neutrons, such as LiCaAlF6:Eu, which has a light yield of more than 1500 photons/neutron, and a scintillator for detecting gamma rays, which has a permeable end on a shorter wavelength than the light emission wavelength of the thermal neutron scintillator.

Abstract: [Problems to be Solved] A radiation detector, which is improved in the detection efficiency of a photodetector for light emitted by a scintillator, which has excellent long-term operational stability, and which is excellent in time resolution and count rate characteristics, is provided with the use of the scintillator with a short fluorescence lifetime. [Means to Solve the Problems] A radiation detector is constructed by installing an optical wavelength conversion layer, which is composed of, for example, an organic fluorescent substance using polyvinyltoluene as a base material, between a scintillator composed of a fluoride single crystal, such as a Ce-containing LiCaAlF6 crystal, and a photodetector having a light entrance window material composed of a transparent glass material such as borosilicate glass. In the radiation detector, the peak wavelength of light emitted by the scintillator is 360 nm or less, and the peak wavelength of light after conversion by the optical conversion layer is 400 nm or more.

Abstract: A neutron measurement apparatus 1A includes a neutron detection unit 10, a photodetection unit 20 that detects scintillation light emitted from the neutron detection unit 10, a light guide optical system 15 that guides the scintillation light from the neutron detection unit 10 to the photodetection unit 20, and a shielding member 30 which is located between the neutron detection unit 10 and the photodetection unit 20 for shielding radiation passing in a direction toward the photodetection unit 20. Further, a scintillator formed of a lithium glass material in which PrF3 is doped to a glass material 20Al(PO3)3-80LiF is used as a neutron detection scintillator composing the neutron detection unit 10. Thereby, the neutron detection scintillator and the neutron measurement apparatus which are capable of suitably performing neutron measurement such as measurement of scattered neutrons from an implosion plasma can be realized.

Abstract: [Problems to be Solved] A neutron scintillator excellent in neutron detection efficiency and n/? discrimination ability, and a neutron detector using the neutron scintillator are provided. [Means to Solve the Problems] A neutron scintillator comprising a eutectic body composed of laminar lithium fluoride crystals and laminar calcium fluoride crystals alternately arranged in layers, the thickness of the lithium fluoride crystal layers in the eutectic body being 0.1 to 5 ?m; or a neutron scintillator comprising a eutectic body composed of laminar lithium fluoride crystals and laminar calcium fluoride crystals alternately arranged in layers, the calcium fluoride crystal layers in the eutectic body being linearly continuous in at least one direction; and a neutron detector basically constructed from any of the neutron scintillators and a photodetector.

Abstract: [Problems to be Solved] A fluoride which emits light with high brightness in a vacuum ultraviolet region is provided. Also provided are a novel vacuum ultraviolet light emitting element which comprises the fluoride and which can be suitably used in photolithography, cleaning of a semiconductor or liquid crystal substrate, sterilization, next-generation large-capacity optical disks, medical care (ophthalmologic treatment, DNA cleavage), etc.; and a vacuum ultraviolet light emitting scintillator which is composed of the fluoride and can be suitably used in a small-sized radiation detector incorporating a diamond light receiving element or AlGaN light receiving element with a low background noise as an alternative to a conventional photomultiplier tube. [Means to Solve the Problems] A metal fluoride crystal represented by a chemical formula K3-XNaXTmYZLuY(1-Z)F3+3Y where 0.7<X<1.3, 0.85<Y<1.1 and 0.001?Z<1.0, such as K2NaTm0.4Lu0.6F6, K2.1Na0.9TmF6, K2NaTmF6, or K2NaTm0.9F5.

Abstract: A vacuum ultraviolet light emitting device comprising: a luminescence substrate which is composed of a transparent substrate of lithium fluoride, magnesium fluoride, calcium fluoride, barium fluoride or the like, and a metal fluoride thin-film layer formed on the transparent substrate and being a thin-film layer of a metal fluoride such as LuLiF4, LaF3, BaF2 or CaF2, the metal fluoride being doped with atoms of neodymium (Nd), thulium (Tm), erbium (Er) or the like; and an electron beam source such as a thermionic emission gun or a field emission gun, wherein the luminescence substrate and the electron beam source are disposed in a vacuum atmosphere, and the metal fluoride thin-film layer is irradiated with electron beams from the electron beam source to emit light including wavelength components of vacuum ultraviolet light.

Abstract: A neutron measurement apparatus 1A includes a neutron detection unit 10, a photodetection unit 20 that detects scintillation light emitted from the neutron detection unit 10, a light guide optical system 15 that guides the scintillation light from the neutron detection unit 10 to the photodetection unit 20, and a shielding member 30 which is located between the neutron detection unit 10 and the photodetection unit 20 for shielding radiation passing in a direction toward the photodetection unit 20. Further, a scintillator formed of a lithium glass material in which PrF3 is doped to a glass material 20Al(PO3)3-80LiF is used as a neutron detection scintillator composing the neutron detection unit 10. Thereby, the neutron detection scintillator and the neutron measurement apparatus which are capable of suitably performing neutron measurement such as measurement of scattered neutrons from an implosion plasma can be realized.

Abstract: [Problems to be Solved] The present invention aims to provide a scintillator which can detect photons of high energy, such as hard X-rays or ?-rays, with high sensitivity. [Means to Solve the Problems] A scintillator comprises lithium lutetium fluoride containing neodymium as a luminescence center, the lithium lutetium fluoride being represented by the chemical formula LiLu1-xNdxF4 where x is in the range of 0.00001 to 0.2, preferably, 0.0001 to 0.05. Preferably, the scintillator comprises a single crystal of the lithium lutetium fluoride containing neodymium.

Abstract: [Problems to be Solved] It is an object of the present invention to provide a novel radiographic image detector which can detect radiation, such as hard X-rays or ?-rays, with high sensitivity and which is excellent in position resolution and count rate characteristic. [Means to Solve the Problems] A radiographic image detector comprises a combination of a scintillator, such as a lanthanum fluoride crystal containing neodymium, for converting incident radiation into ultraviolet rays; and a gas multiplication ultraviolet image detector for converting ultraviolet rays into electrons, amplifying such electrons by use of a gas electron avalanche phenomenon, and detecting the electrons.

Abstract: A scintillator for neutron detection, comprising a metal fluoride crystal containing, as constituent elements, a metal having a valence of 2 or higher, such as calcium, aluminum or yttrium; lithium; and fluorine, the metal fluoride crystal containing 1.1 to 20 atoms per unit volume (atoms/nm3) of 6Li, having an effective atomic number of 10 to 40, containing a lanthanoid such as cerium, praseodymium or europium, and being represented by, for instance, LiCaAlF6, LiSrAlF6 and LiYF4. The scintillator for neutron detection has high sensitivity to neutron rays, and is reduced in a background noise attributed to ? rays.

Abstract: [Problems to be Solved] To provide a novel ultraviolet light receiving element which is selectively sensitive to ultraviolet radiation, and a method for measuring the dose of ultraviolet radiation using the ultraviolet light receiving element. [Means to Solve the Problems] An ultraviolet detecting layer composed of a thin film of a metal fluoride, such as cerium fluoride, lithium fluoride, magnesium fluoride or calcium fluoride, is formed on a substrate of silica glass, sapphire or the like. Further, at least a pair of an anode and a cathode are formed on the ultraviolet detecting layer to prepare an ultraviolet light receiving element. This ultraviolet light receiving element changes in electric resistivity in accordance with the dose of incident ultraviolet radiation. Thus, the dose of ultraviolet radiation can be measured by taking out and measuring the change as an electric signal.

Abstract: [Problem] To provide a method of producing a pretreated metal fluoride containing impurities such as oxygen in decreased amounts and a fluoride crystal containing impurities such as oxygen in decreased amounts and having excellent optical properties such as transparency. [Means for Solution] A metal fluoride is heated in a temperature range of not lower than 300° K. but not higher than 1780° K in the co-presence of a carbonyl fluoride of an amount of not less than 1/100 mol per mol of the metal fluoride to thereby obtain a pretreated metal fluoride while removing oxygen and water from the starting metal fluoride and from the interior of the production furnace. Further, the pretreated metal fluoride as a starting material is heated and melted, and a fluoride crystal of a high quality is obtained from the obtained melt by a crystal growing method such as a melt pull-up method or a melt pull-down method.

Abstract: To provide a scintillator for neutron detection which has high sensitivity to neutron rays, and is reduced in a background noise attributed to ? rays. [Means to Solve the Problems] A scintillator for neutron detection, comprising a metal fluoride crystal containing, as constituent elements, a metal having a valence of 2 or higher, such as calcium, aluminum or yttrium; lithium; and fluorine, the metal fluoride crystal containing 1.1 to 20 atoms per unit volume (atoms/nm3) of 6Li, having an effective atomic number of 10 to 40, containing a lanthanoid such as cerium, praseodymium or europium, and being represented by LiCaAlF6, LiSrAlF6, LiYF4 etc.

Abstract: A radiation detecting apparatus of the present invention is an apparatus comprising a scintillator for converting incident radiation into ultraviolet radiation having a wavelength of 220 nm or less, the scintillator being composed of, for example, Nd-doped LaF3 crystals; and a diamond thin film sensor for guiding the resulting ultraviolet radiation and converting it into an electrical signal, the radiation detecting apparatus being adapted to transform the incident radiation to the electrical signal. The radiation detecting apparatus can detect radiation, such as X-rays, ? rays, ? rays, ? rays, or neutron rays, with high sensitivity. The radiation detecting apparatus also has a fast response, is very easy to downsize, has high resistance to radiation, and can be preferably used in the medical field, the industrial field, or the security field.

Abstract: A radiation detection apparatus comprising a scintillator composed of a lanthanum fluoride crystal containing neodymium or a lithium barium fluoride crystal containing neodymium, for converting incident radiation into ultraviolet ray and a micro-strip gas chamber for converting the incident ultraviolet ray into an electric signal and capable of extracting the radiation as an electric signal. The radiation detection apparatus which has excellent spatial resolution and can detect even a high-energy photon at high sensitivity is provided at low cost.

Abstract: A method of thinning lateral flowers of apples, comprising applying of flower thinning effective amount of a pyrazole compound represented by general formula (I) ##STR1## wherein R.sub.1 represents an alkyl group having 1 to 4 carbon atoms; andR.sub.2 and R.sub.3, which are the same or different, each represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms,to flowers of apples. A compound in which R.sub.1 and R.sub.2 are each a methyl group, and R.sub.3 is a hydrogen atom is preferred. The pyrazole compounds are applied at a flowering stage of apples, preferably in a period from immediately after full bloom to terminal flowers of apples to 2 days thereafter, typically in a proportion of from about 5 mg to about 75 g per tree at a coverage in a range of from about 20 mg/10a to about 2,000 g/10a.