WO2012090936A1 - Matériau luminescent pour scintillateur, scintillateur l'utilisant et détecteur de rayonnement et appareil d'inspection de rayonnement l'utilisant - Google Patents

Matériau luminescent pour scintillateur, scintillateur l'utilisant et détecteur de rayonnement et appareil d'inspection de rayonnement l'utilisant Download PDF

Info

Publication number
WO2012090936A1
WO2012090936A1 PCT/JP2011/080076 JP2011080076W WO2012090936A1 WO 2012090936 A1 WO2012090936 A1 WO 2012090936A1 JP 2011080076 W JP2011080076 W JP 2011080076W WO 2012090936 A1 WO2012090936 A1 WO 2012090936A1
Authority
WO
WIPO (PCT)
Prior art keywords
scintillator
light
raw material
radiation
radiation detector
Prior art date
Application number
PCT/JP2011/080076
Other languages
English (en)
Japanese (ja)
Inventor
吉川　彰
健之 柳田
藤本　裕
秀喜 八木
柳谷　高公
Original Assignee
国立大学法人東北大学
神島化学工業株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 国立大学法人東北大学, 神島化学工業株式会社 filed Critical 国立大学法人東北大学
Publication of WO2012090936A1 publication Critical patent/WO2012090936A1/fr

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01T—MEASUREMENT OF NUCLEAR OR X-RADIATION
    • G01T1/00—Measuring X-radiation, gamma radiation, corpuscular radiation, or cosmic radiation
    • G01T1/16—Measuring radiation intensity
    • G01T1/20—Measuring radiation intensity with scintillation detectors
    • G01T1/202—Measuring radiation intensity with scintillation detectors the detector being a crystal
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/50—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on rare-earth compounds
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/50—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on rare-earth compounds
    • C04B35/505—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on rare-earth compounds based on yttrium oxide
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
    • C09K11/08—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
    • C09K11/77—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals
    • C09K11/7766—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals containing two or more rare earth metals
    • C09K11/7767—Chalcogenides
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3224—Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3224—Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide
    • C04B2235/3227—Lanthanum oxide or oxide-forming salts thereof
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/50—Constituents or additives of the starting mixture chosen for their shape or used because of their shape or their physical appearance
    • C04B2235/54—Particle size related information
    • C04B2235/5409—Particle size related information expressed by specific surface values
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/50—Constituents or additives of the starting mixture chosen for their shape or used because of their shape or their physical appearance
    • C04B2235/54—Particle size related information
    • C04B2235/549—Particle size related information the particle size being expressed by crystallite size or primary particle size
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
    • C04B2235/658—Atmosphere during thermal treatment
    • C04B2235/6581—Total pressure below 1 atmosphere, e.g. vacuum
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
    • C04B2235/96—Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
    • C04B2235/9646—Optical properties

Definitions

  • the present invention relates to a luminescent material for a scintillator, a scintillator using the luminescent material, a radiation detector using the scintillator, and a radiation inspection apparatus.
  • Positrons are also called positrons.
  • a positron emitting drug is administered into a subject.
  • a positron emitting pharmaceutical is a compound labeled with a positron emitting nuclide, and is produced by irradiating a compound with protons or deuterons with cycloton or the like.
  • the positron emitting nuclide administered into the subject decays in the body and generates one positron. These positrons annihilate with the electrons of neighboring atoms. At this time, two oppositely directed ⁇ rays having energy of 511 keV are generated by the interaction between the positron and the corresponding electron.
  • the ⁇ rays enter a scintillator crystal in the scintillator and are converted into light (photons). This light is detected by the light receiving element. In this way, light emitted from a specific position in the subject is converted into an electrical signal through the scintillator and detected.
  • a photodiode (PD) or a photomultiplier tube (PMT) is used as the light receiving element.
  • PET Examination using PET is being used for diagnosis of clinical stage by diagnosis of tumor grade before treatment, detection of cancer invasion range and metastatic lesion, etc.
  • a PET test is expected to provide highly accurate information for determination and evaluation of response to cancer treatment during treatment or immediately after treatment, prognosis prediction after treatment, recurrence diagnosis, etc.
  • Clinical application is widespread.
  • materials used as light-emitting materials for scintillators are materials using the 5d-4f transition of Ce 3+ (trivalent cerium ion) as typified by Ce: GSO, Ce: LSO, and Ce: YAP. (See Non-Patent Document 1).
  • Ce 3+ trivalent cerium ion
  • Ce: GSO, Ce: LSO, and Ce: YAP typified by Ce: GSO, Ce: LSO, and Ce: YAP.
  • a normal Ce-based scintillator crystal made of such a light emitting material for scintillator has a fluorescence lifetime of several tens of ns (see Non-Patent Document 2).
  • a radiation detector having a high response speed is required in order to reduce counting down.
  • the PET apparatus is required to reduce the burden on the subject to be examined by shortening the examination time.
  • a radiation detector used for PET or the like is required to have a high temporal resolution capable of preventing a phenomenon in which a plurality of fluorescences overlap, that is, a so-called pile-up phenomenon.
  • pile-up phenomenon a phenomenon in which a plurality of fluorescences overlap
  • Non-Patent Document 2 since the general scintillator crystal described in Non-Patent Document 2 has a fluorescence lifetime of several tens of ns, a high-speed response of, for example, 1 ns or less has not been obtained. 1 ns is 10 -9 seconds.
  • Patent Document 1 describes that the scintillator has a time resolution of 1 ns or less, but does not show the specific configuration of the scintillator and data related to the time response.
  • the present invention provides a scintillator light-emitting material that exhibits an extremely short fluorescence lifetime of sub-nanoseconds to 5 ns, a scintillator using the novel light-emitting material, a radiation detector equipped with the scintillator, and a radiation inspection apparatus The purpose is to provide.
  • the present inventors have found that Yb mixed crystal rare earth oxide operates as a scintillator that responds at high speed at room temperature. By combining with an appropriate light receiving element, the present inventors realized a radiation detector with excellent characteristics and a high-speed response. The invention has been reached.
  • the light-emitting material for scintillators of the present invention has a chemical formula (R 1-X Yb X ) 2 O 3 (where R is a rare earth element composed of Sc, Y and a lanthanoid) One or more elements selected from the group consisting of 0 ⁇ x ⁇ 0.1).
  • R is a rare earth element composed of Sc, Y and a lanthanoid
  • the rare earth element is preferably one or more elements selected from Sc, Y, La, Gd, and Lu.
  • the scintillator luminescent material preferably emits fluorescence having an emission peak wavelength in a wavelength region of about 300 to 600 nm by irradiation with radiation.
  • the light emitting material for scintillator is preferably transparent with little absorption in the wavelength region of 300 to 530 nm corresponding to the emission peak wavelength.
  • the scintillator light-emitting material preferably emits fluorescence resulting from a transition from the charge transfer state (CTS) of Yb 3+ .
  • CTS charge transfer state
  • the scintillator luminescent material is preferably made of polycrystal or crystal.
  • the scintillator light-emitting material of the present invention is characterized by being composed of any of the above-described scintillator light-emitting materials.
  • the fluorescence lifetime at room temperature is preferably 5 ns or less.
  • a radiation detector includes a scintillator made of any one of the above-described scintillator light emitting materials and a light receiving element that receives fluorescence from the scintillator.
  • the light receiving element is preferably any one of a photomultiplier tube, a photodiode, an avalanche photodiode, a Geiger mode avalanche photodiode, an image intensifier, and a charge coupled device.
  • a radiation inspection apparatus includes the radiation detector described above.
  • a method for producing a light-emitting material for scintillator according to the present invention is a method for producing a light-emitting material for scintillator according to any one of the above, wherein the raw material powder is molded by mixing the following R oxide powder and Yb oxide powder: A polycrystal of (R 1-X Yb X ) 2 O 3 is produced by firing the molded body for a predetermined time.
  • the oxide powder preferably has a BET specific surface area of 2 m 2 / g or more and 15 m 2 / g or less, and secondary aggregated particles exceeding 5 ⁇ m are 10% or less by mass fraction. It is good also considering the density of a molded object as 58% or more.
  • a single crystal of a light emitting material for scintillator may be grown using raw material powder having a composition represented by the chemical formula.
  • the light emitting material for scintillator of the present invention has the chemical formula (R 1-X Yb X ) 2 O 3 (where R is one or more elements selected from rare earth elements composed of Sc, Y and lanthanoids). 0 ⁇ x ⁇ 0.1) and exhibits a very short fluorescence lifetime of sub-nanoseconds to 5 ns, and can be applied to a high-speed scintillator for radiation.
  • the radiation detector of the present invention since the high-speed scintillator and the light-receiving element having a high response speed are combined, high-speed response, high time resolution, and pile-up can be prevented. Less radiation can be detected with high accuracy.
  • the radiation detector described above since the radiation detector described above is provided, it can be applied to, for example, an image diagnostic apparatus using the PET method, and radiation can be detected with high accuracy.
  • FIG. 1 Energy wave height distribution when 0.66 MeV gamma ray from a 137 Cs source is detected using the radiation detector comprising the scintillator (Lu X0.997 Yb 0.003 ) 2 O 3 and a photomultiplier tube of Example 1.
  • FIG. 1 Using the radiation detector comprising the scintillator (Lu X0.997 Yb 0.003 ) 2 O 3 and a photomultiplier tube of Example 1, the energy wave height distribution when detecting 0.66 MeV ⁇ -rays from a 137 Cs radiation source is shown.
  • FIG. 1 Using the radiation detector comprising the scintillator (Lu X0.997 Yb 0.003 ) 2 O 3 and an avalanche photodiode of Example 1, the energy wave height distribution when detecting 0.66 MeV ⁇ -rays from a 137 Cs radiation source is shown.
  • the radiation detector comprising the scintillator (Lu X0.997 Yb 0.003 ) 2 O 3 and an avalanche photodiode of Example 1
  • the energy wave height distribution when detecting 1.8 MeV ⁇ -ray from a 90 Sr radiation source is shown.
  • FIG. Using the scintillator of Example 1 (Lu X0.997 Yb 0.003 ) 2 O 3 and an avalanche photodiode, the energy wave height distribution when detecting 5.5 MeV ⁇ -ray from a 241 Am radiation source is shown.
  • FIG. 1 Energy wave height when detecting 1.8 MeV ⁇ -ray from 90 Sr source using radiation detector comprising scintillator (Lu X0.997 Yb 0.003 ) 2 O 3 and Geiger mode avalanche photodiode of Example 1 It is a figure which shows distribution.
  • Micro pulling device 2 Melt 3: Crucible 3a: Fine pore 4: Seed crystal holding unit 4a: Seed crystal 5: Moving mechanism unit 5a: Pulling shaft 5b: Moving mechanism 5c: Moving mechanism control unit 6: Induction heating unit 6a: induction heating coil 7: furnace material 7a: heat insulating material 7b: after heater 8: crystal synthesis chamber 8a: vacuum exhaust unit 8b: gas introduction unit 9: single crystal 10: radiation detector 12: chamber 13: scintillator 14: light reception Element 14a: Power connection terminal 14b: Output terminal 15: Reflector 17: Read circuit 20, 20a: Radiation inspection apparatus 22: Bias power supply 23: Preamplifier 24: Waveform shaping amplifier 25: Multichannel analyzer 26: Computer 30: Radiation source 31: Image intensifier (IIT) 32: CCD 33: Read circuit 34: High voltage power supply
  • the light-emitting material for scintillator has a chemical formula (R 1-X Yb X ) 2 O 3 (where R is selected from rare earth elements composed of Sc, Y and lanthanoids). It is a transparent ceramic represented by 0 ⁇ x ⁇ 0.1. Lanthanoids are elements having element numbers 57 to 71.
  • the composition x of Yb serving as the emission center is set to be larger than 0 so that Yb is the emission center, and the upper limit is set to x ⁇ 0.1. This is because, as will be described later, if the amount of CTS of Yb 3+ is too large, concentration quenching occurs and the light emission amount decreases.
  • the light emitting material for scintillator of the present invention generates fluorescence having an emission peak wavelength in a wavelength region of about 300 to 600 nm when irradiated with radiation.
  • the generation of this fluorescence is Yb which is an element that forms an optically active state called a charge transfer state (hereinafter referred to as CTS) with oxygen ions, which are adjacent negative ions in the light emitting material.
  • CTS charge transfer state
  • oxygen ions which are adjacent negative ions in the light emitting material.
  • radiation refers to particles ( ⁇ rays, ⁇ rays, neutron rays, etc.) and photons ( ⁇ rays, X rays, etc.) having sufficient energy to ionize atoms and molecules.
  • R is one or more elements selected from rare earth elements composed of Sc (scandium), Y (yttrium) and lanthanoids.
  • Sc scandium
  • Y yttrium
  • lanthanoids Preferably, one or more elements selected from Sc, Y, La (lanthanum), Gd (gadolinium), Lu (lutetium) and the like can be used.
  • the composition x of the chemical formula (R 1-X Yb X ) 2 O 3 is 0 ⁇ x ⁇ 0.006, more preferably 0.001 ⁇ x ⁇ 0.005 may be satisfied. It is not preferable that the composition x of Yb is less than 0.001 because the amount of light emission becomes low because the CTS of Yb 3+ serving as the emission center is too small. Conversely, the upper limit is set to a value that does not cause a decrease in the amount of light emission due to the concentration quenching of Yb 3+ .
  • the composition x of Yb may be smaller than 0.006 or smaller than 0.005.
  • the response speed is shorter than 1 ns.
  • FIG. 1 is a schematic diagram for explaining CTS by Yb ions contained in the light emitting material for scintillator of the present invention.
  • Yb 3+ cations form an optically active state called CTS with oxygen ions, which are adjacent anions.
  • the scintillator is irradiated with radiation, the Yb 3+ cation shown on the left side of FIG. 1 interacts with surrounding O, and the electron in the ground state 4f 13 2P 6 state is the excitation level 4f 14 excited to 2P 5, the fluorescence is emitted in the process of relaxation (see the right side in FIG. 1).
  • Non-Patent Documents 1 and 2 which is a conventional additive for a scintillator luminescent material, forms an excited state of a 5d-4f transition in its nucleus.
  • CTS formed by the interaction of Yb ions and O is not in the nucleus of Yb, but is in an excited state. The light emission accompanying the transition from this state.
  • the fluorescence lifetime from CTS by Yb 3+ contained in the light emitting material for scintillator of the present invention is 100 to 300 ns at low temperature and 1 to 5 ns at room temperature.
  • the fluorescence lifetime at room temperature from CTS by Yb 3+ is about one order of magnitude faster than the conventional Ce 3+ fluorescence lifetime of 10 to 80 ns.
  • the wavelength range of fluorescence from CTS by Yb 3+ ranges from UV to red.
  • the wavelength range of conventional Ce 3+ fluorescence is from UV to blue. From now on, since the fluorescence wavelength region from the light emitting material for scintillators of the present invention is wider than the conventional Ce 3+ fluorescence wavelength region and covers visible light up to red, various semiconductor detections described later are used for fluorescence detection. Can be used.
  • the CTS with Yb 3+ has a large Stokes shift, whereas the conventional Ce 3+ has a small Stokes shift.
  • the fluorescence lifetime at room temperature is shorter than 5 ns due to thermal quenching.
  • the temperature dependence of the light emission amount depends on the composition other than Yb serving as the light emission center, that is, the host. For this reason, the fluorescence lifetime can be changed by combining with a host that exhibits a high light emission amount even at room temperature.
  • Table 1 summarizes the comparison of fluorescence lifetime, fluorescence wavelength region, Stokes shift, and concentration quenching in the Yb 3+ CTS and Ce 3+ 5d-4f transitions according to the present invention.
  • a sintered body or a single crystal made of polycrystal can be used as the scintillator light emitting material.
  • a sintered body made of polycrystal is also simply called ceramics.
  • a scintillator light-emitting material made of a polycrystalline sintered body can be produced by mixing raw materials, solidifying and firing this raw material powder.
  • a single crystal of a scintillator luminescent material can be grown by a melt growth method such as the Bridgman method, the zone melt method, the Bernoulli method, the heat exchange method, the CZ method, the FZ method, or the micro-pulling down method.
  • the polycrystal used as the raw material of the single crystal the same raw material as the polycrystal used as the light emitting material for the scintillator can be used.
  • Each raw material powder of (R 1-X Yb X ) 2 O 3 includes an oxide of R And ytterbium oxide (Yb 2 O 3 ) which is an oxide of Yb can be used.
  • the oxide of R include scandium oxide (Sc 2 O 3 ), yttrium oxide (Y 2 O 3 ), and lanthanoid oxides.
  • lanthanoid oxides include lutetium oxide (Lu 2 O 3 ) and gadolinium oxide (Gd 2 O 3 ).
  • Each raw material powder has a purity of 99.9% or more, a BET value (BET specific surface area) of 2 m 2 / g or more and 15 m 2 / g or less, and secondary aggregated particles exceeding 5 ⁇ m are 10% or less by mass fraction.
  • This raw material powder is molded to form a raw material powder compact.
  • This raw material powder compact is sintered at a temperature of 1750 ° C. or lower, which is extremely lower than the melting point, to synthesize a translucent sintered body. In order to make the average particle diameter of the translucent sintered body 20 ⁇ m or less, it is necessary to produce a high-density molded body.
  • the raw material powder compact before sintering may have a compact density of 58% or more empirically after degreasing.
  • the BET value of the raw material powder exceeds 15 m 2 / g, it is too fine to handle, and it is difficult to increase the density of the compact.
  • the BET value of the raw material powder is less than 2 m 2 / g, it is not preferable because it is not easy to densify at a low temperature.
  • the BET value of the raw material powder used is set to 2 m 2 / g or more and 15 m 2 / g or less.
  • the BET value of the raw material powder is more preferably about 4 m 2 / g or more and 8 m 2 / g or less.
  • a secondary agglomerated particle exceeding 5 ⁇ m is preferably a raw material powder having a mass fraction of 10% or less, preferably 5% or less, and a uniform particle size distribution.
  • a high-density molded body cannot be obtained, which is not preferable.
  • FIG. 2 is a schematic diagram showing the micro pull-down device 1.
  • the micro-pulling device 1 includes a crucible 3 that holds a melt 2 and a seed crystal that holds a seed crystal 4 a that is brought into contact with the melt 2 flowing out from a pore 3 a provided at the bottom of the crucible 3.
  • a holding unit 4, a moving mechanism unit 5 that moves the seed crystal holding unit 4 downward, and an induction heating unit 6 that heats the crucible 3 are provided.
  • a heat insulating material 7 a made of zirconia or the like is disposed as the furnace material 7.
  • the crucible 3 is accommodated in a crystal synthesis chamber 8 made of a quartz tube or the like disposed outside the heat insulating material 7.
  • the crystal synthesis chamber 8 includes a vacuum exhaust unit 8a and a gas introduction unit 8b, and is a container that can be evacuated.
  • the induction heating unit 6 that heats the crucible 3 includes an induction heating coil 6a that heats the crucible 3, an AC frequency power source (not shown) that supplies power to the induction heating coil 6a, and the like.
  • the moving mechanism unit 5 includes a pulling shaft 5a that moves the seed crystal holding unit 4 downward, a moving mechanism 5b that moves the pulling shaft 5a in the vertical direction, and a moving mechanism control unit 5c.
  • the moving mechanism control unit 5c performs position control of the pulling shaft 5a, speed control for moving the pulling shaft 5a downward during single crystal growth, and the like.
  • An after heater 7b which is a heating element, is disposed on the outer periphery of the bottom of the crucible 3.
  • the heating temperature of the solid-liquid boundary phase of the melt 2 drawn from the pores provided at the bottom of the crucible 3 is controlled by the crucible 3 and the after heater 7b heated by the induction heating coil 6a.
  • the polycrystal of (R 1-X Yb X ) 2 O 3 described above is put in the crucible 3 as a raw material, and the crystal synthesis chamber 8 is evacuated by the vacuum exhaust part 8a, and then the gas introduction part 8b enters the crystal synthesis chamber 8
  • An inert gas Ar is introduced to make the inside of the crystal synthesis chamber 8 an inert gas atmosphere.
  • the inert gas Ar (85 to 99%) may be a mixed gas in which hydrogen gas (H 2 , 1 to 15%) is mixed to prevent the crucible 3 from being oxidized.
  • the crucible 3 is heated by the induction heating coil 6a and the after heater 7b to completely melt the raw material in the crucible 3.
  • the seed crystal 4a is gradually raised at a predetermined speed, and the tip of the seed crystal 4a is brought into contact with the pores at the lower end of the crucible 3 so that the seed crystal 4a is sufficiently adapted. Then, the single crystal 9 is grown by lowering the pulling shaft 5a while adjusting the melt temperature. When the melt 2 in the crucible 3 is all crystallized and the melt 2 is exhausted, the crystal growth is terminated.
  • the micro-pulling device 1 When the micro-pulling device 1 is used, the effective segregation coefficient at the time of single crystallization from the melt is close to 1, and the light emitting material for scintillator is compared with the case of using the conventional pulling method or Bridgman method. There is an advantage that variation in composition is reduced. Compared with the conventional pulling method and Bridgman method, which requires a week to grow a single crystal of one composition, the micro pulling method has the advantage that it takes 5 to 10 hours. Can do growth.
  • FIG. 3 is a cross-sectional view showing the configuration of the radiation detector 10 according to the first exemplary embodiment of the present invention.
  • the radiation detector 10 of the present invention includes a chamber 12, a scintillator 13 accommodated in the chamber 12, a light receiving element 14 that detects fluorescence from the scintillator 13, and a reflector 15. It is configured.
  • the light receiving element 14 is provided in contact with the lower surface of the scintillator 13.
  • the fluorescent material may be covered with a reflector 15 so that the fluorescence does not leak outside the scintillator 13.
  • the light receiving element 14 includes a power connection terminal 14a to which power is supplied and an output terminal 14b.
  • the light receiving element 14 converts the fluorescence emitted from the scintillator 13 made of (R 1 ⁇ X Yb X ) 2 O 3 into an electrical signal.
  • the material of the scintillator 13 made of (R 1-X Yb X ) 2 O 3 is also called Yb mixed crystal rare earth oxide.
  • the light receiving element 14 is preferably capable of detecting the emission peak wavelength of the scintillator 13, that is, the wavelength region of 300 to 600 nm, and has high quantum conversion efficiency.
  • the quantum conversion efficiency is preferably 10% or more.
  • a photomultiplier tube PMT
  • PD photodiode
  • APD avalanche photodiode
  • IIT image intensifier
  • a charge coupled device also referred to as a charge coupled device or CCD
  • Examples of commercially available products that can be used for the light receiving element 14 include photomultiplier tubes, photodiodes, avalanche photodiodes, Geiger mode avalanche photodiodes manufactured by Hamamatsu Photonics Co., Ltd., and the like. Each of these light receiving elements 14 can detect a wavelength region of 200 nm to 900 nm, and has a quantum conversion efficiency of 10% or more in a wavelength region of 300 nm to 600 nm.
  • the Yb mixed crystal rare earth oxide scintillator 13 has a fluorescence lifetime of 0.05 ns to 5 ns seconds due to light emission resulting from the transition from the charge transfer state (CTS) of Yb 3+ .
  • the scintillator 13 made of Yb mixed crystal rare earth oxide has an emission peak wavelength in the range of 300 nm to 600 nm.
  • the operation of the radiation detector 10 will be described.
  • the radiation detector 10 when the radiation enters the Yb mixed crystal rare earth oxide scintillator 13, the Yb mixed crystal rare earth oxide scintillator 13 emits fluorescence, and the light receiving element 14 detects this fluorescence and converts it into an electrical signal. Output.
  • both the Yb mixed crystal rare earth oxide scintillator 13 and the light receiving element 14 have high-speed response in the sub-nanosecond range of 0.05 ns to 1 ns. Furthermore, since the Yb mixed crystal rare earth oxide scintillator 13 contains an element having a high effective atomic number Z eff such as Lu as a constituent element of the mother crystal structure, it can detect radiation with high sensitivity and high accuracy. For this reason, the time resolution of the radiation detector 10 is also increased. Thereby, the radiation detector 10 has high time resolution and can prevent pile-up. For this reason, counting down decreases.
  • FIG. 4 is a block diagram showing the configuration of the radiation inspection apparatus 20 according to the second embodiment of the present invention.
  • the radiation inspection apparatus 20 of the present invention includes the radiation detector 10 described above, a bias power source 22, a preamplifier 23, a waveform shaping amplifier 24, a multichannel analyzer 25, a computer 26, and a radiation detector. And a radiation source 30.
  • the bias power source 22 is connected to the power connection terminal 14 a of the light receiving element 14 in order to supply power to the radiation detector 10.
  • the preamplifier 23 is connected to the output terminal 14b of the light receiving element 14, and amplifies the electric signal output from the light receiving element 14.
  • the waveform shaping amplifier 24 is connected to the preamplifier 23, and shapes and further amplifies the signal waveform output from the preamplifier 23.
  • the multi-channel analyzer 25 is connected to the waveform shaping amplifier 24 and receives a signal from the waveform shaping amplifier 24 to perform sampling, data storage, data display, and the like.
  • a computer such as a personal computer (PC) can be used as the computer 26.
  • the computer 26 is connected to the multi-channel analyzer 25 and can execute various arithmetic processes on the measurement data. Thereby, the radiation inspection apparatus 20 can detect the radiation from the radiation source 30 with the radiation detector 10, can preserve
  • FIG. 5 is a block diagram showing a configuration of a modification of the radiation inspection apparatus 20 according to the second embodiment of the present invention.
  • the radiation inspection apparatus 20 a of the present invention uses the light receiving element 14 of the radiation detector 10 as an image intensifier (IIT) 31, and further receives the output light from the image intensifier 31 by the CCD 32.
  • the readout circuit 33 for reading out the output from the CCD 32 is outputted to the personal computer 26.
  • a high voltage power supply 34 is connected to the image intensifier 31 as a bias power supply.
  • the readout circuit 33 includes an amplifier, an A / D converter that converts an amplified analog signal into a digital signal, and the like.
  • the radiation inspection apparatuses 20 and 20a can configure, for example, PET, X-ray CT, SPECT (single photon emission tomography), etc., depending on the radiation source 30 used.
  • the radiation inspection apparatuses 20 and 20a are not particularly limited when made of PET, but are MRI-PET, CT-PET, two-dimensional PET, three-dimensional PET, time-of-flight positron emission apparatus (TOF type PET). It is preferably made of depth detection (DOI) type PET, OPEN-PET. Furthermore, the radiation inspection apparatuses 20 and 20a may be configured by a combination of these.
  • TOF type PET which is currently expected to be realized, differs from the conventional two scintillators, that is, a method of detecting with equal probability on a straight line (LOR) connecting both detectors.
  • the coordinate point of the radiation source 30 is obtained from the difference in measurement time, and the distribution blurred with a Gaussian function corresponding to the time resolution of the detector along the LOR is used as position information. For this reason, the response speed of the conventional scintillator has a position identification capability of less than 100 cm.
  • the fluorescence lifetime of the scintillator 13 is about an order of magnitude faster than that of the conventional scintillator.
  • a position identification capability of several centimeters can be provided, and high performance can be achieved.
  • the radiation inspection apparatus 20 includes the radiation detector 10 having a high-speed response, the data acquisition time can be greatly shortened. For this reason, by using the radiation inspection apparatus 20 for a medical imaging apparatus or the like, the inspection time can be shortened, and the burden on the subject can be greatly reduced.
  • the present invention will be described in more detail by way of examples.
  • a high-purity lutetium chloride solution Shin-Etsu Chemical Co., Ltd.
  • a lutetium chloride aqueous solution 2 liters of an ammonium hydrogen carbonate solution having a concentration of 3 M (mol ⁇ dm ⁇ 3 ) was dropped at a rate of 5 ml per minute, followed by stirring and curing at room temperature for 7 days. After curing, filtration and washing with ultrapure water were repeated several times, and then put into a dryer at 150 ° C. and dried for 3 days to prepare a precursor powder. The obtained precursor powder was put into an alumina crucible and calcined in an electric furnace at 1200 ° C. for 10 hours, whereby lutetium oxide having a BET specific surface area value of 5.0 m 2 / g and an average primary particle size of 0.13 ⁇ m. Raw material powder was prepared.
  • ytterbium oxide raw material powder manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99%, BET specific surface area value 2.7 m 2 / g
  • BET specific surface area value 2.7 m 2 / g BET specific surface area value 2.7 m 2 / g
  • 2 g of Kyoeisha Chemical's Floren G700 (Floren is a trade name of Kyoeisha Chemical) and 0.5 g of Sekisui Chemical's PVB-BL1 (PVB-BL1 is a trade name of Sekisui Chemical) were added as a binder.
  • Ethanol 35g was added to this mixture, and it mixed for 50 hours using the nylon pot and the nylon ball, and was set as the alcohol slurry.
  • the molded article was produced by pouring the alcohol slurry into a gypsum mold and curing for 3 days.
  • the amount of the ytterbium oxide raw material powder may be adjusted.
  • x is 0.01, the amount of the ytterbium oxide raw material powder is set to 0.99 g.
  • the molded body was heated at 5 ° C./hour in an oxygen stream, and degreased at 900 ° C. for 40 hours.
  • the composition ratio of the compact was determined by ICP (inductively coupled plasma) emission spectrometry, and was (Lu 0.997 Yb 0.003 ) 2 O 3 .
  • the compact was further heated to 1200 ° C. and held for 10 hours. Then, it sintered for 10 hours at the temperature of 1650 degreeC in the vacuum baking furnace. At this time, the heating rate was 300 ° C./hour up to 1200 ° C., 50 ° C./hour above that, and the degree of vacuum in the furnace was 10 ⁇ 2 Pa or less.
  • the obtained sintered body was annealed in the atmosphere at 900 ° C. for 50 hours, and then mirror-polished using a diamond slurry to produce a transparent polycrystalline ceramic.
  • FIG. 6 is an optical image showing the transparency of the scintillator crystal made of (Lu X0.99 Yb 0.01 ) 2 O 3 in Example 1. As is apparent from FIG. 6, since the pattern below the scintillator crystal made of (Lu X0.99 Yb 0.01 ) 2 O 3 of Example 1 is seen through, it can be seen that the scintillator crystal is highly transparent.
  • FIG. 7 also shows Lu 2 O 3 data to which Yb is not added for comparison. As is apparent from FIG. 7, it can be seen that there is no absorption in the vicinity of 300 to 530 nm, which is the emission peak due to the transition from the charge transfer state (CTS) of Yb 3+ .
  • CTS charge transfer state
  • the horizontal axis represents wavelength (nm) and the vertical axis represents fluorescence intensity (arbitrary scale).
  • the fluorescence intensity spectrum has two peaks characteristic of the emission peak caused by the transition from the charge transfer state (CTS) of Yb 3+ at around 370 nm and around 480 nm. I understand that.
  • CTS charge transfer state
  • the horizontal axis of FIG. 9 is time (ns), and the vertical axis is the fluorescence count.
  • these scintillators 13 have an extremely short sub-nanosecond fluorescence lifetime of 0.8 ns.
  • the scintillator 13 made of (Lu X0.99 Yb 0.01 ) 2 O 3 has a light emission amount of about 1000 photons / MeV.
  • the radiation detector 10 was manufactured.
  • the reflecting member 14 covering the scintillator 13 a fluororesin tape was used.
  • the light receiving element 14 a photomultiplier tube, an avalanche photodiode, or a Geiger mode avalanche photodiode was used.
  • the radiation detector 10 has a light emission amount of about 1000 photons / MeV when a photomultiplier tube is used as the light receiving element 14.
  • a radiation inspection apparatus 20 was manufactured using the radiation detector 10 of Example 2.
  • the radiation inspection apparatus 20 has the configuration shown in FIG.
  • a radiation source 30 a ⁇ ray having an energy of 0.66 MeV from a 137 Cs source, a ⁇ ray having an energy of 1.8 MeV from a 90 Sr source, and a 241 Am source ⁇ rays with an energy of 5.5 MeV were used.
  • FIG. 10 shows detection of 0.66 MeV ⁇ rays from a 137 Cs source using the radiation detector 10 comprising the scintillator 13 (Lu X0.997 Yb 0.003 ) 2 O 3 and a photomultiplier tube of Example 1. It is a figure which shows energy wave height distribution at the time of doing.
  • the horizontal axis in FIG. 10 is the channel, and the vertical axis is the fluorescence count in each channel.
  • the display in FIGS. 11 to 17 described later is also the same.
  • the radiation detector 10 was able to detect 0.66 MeV ⁇ rays from a 137 Cs radiation source with high sensitivity by using a photomultiplier tube as the light receiving element 14.
  • FIG. 11 shows detection of 1.8 MeV ⁇ -rays from a 90 Sr source using the radiation detector 10 comprising the scintillator 13 (Lu X0.997 Yb 0.003 ) 2 O 3 and a photomultiplier tube of Example 1. It is a figure which shows energy wave height distribution at the time of doing. As shown in FIG. 11, the radiation detector 10 was able to detect the 1.8 MeV ⁇ -ray from the 90 Sr radiation source with high sensitivity using a photomultiplier tube as the light receiving element 14.
  • FIG. 12 shows detection of 5.5 MeV ⁇ -rays from a 241 Am radiation source using the radiation detector 10 composed of the scintillator 13 (Lu X0.997 Yb 0.003 ) 2 O 3 and a photomultiplier tube of Example 1. It is a figure which shows energy wave height distribution at the time of doing. As shown in FIG. 12, the radiation detector 10 was able to detect 5.5 MeV ⁇ rays from a 241 Am radiation source with high sensitivity by using a photomultiplier tube as the light receiving element 14.
  • FIG. 13 shows the detection of 0.66 MeV ⁇ rays from a 137 Cs source using the radiation detector 10 comprising the scintillator 13 (Lu X0.997 Yb 0.003 ) 2 O 3 and an avalanche photodiode in Example 1. It is a figure which shows energy wave height distribution at the time.
  • the ⁇ -ray signal is shown by a straight line, and the gentle slope in the figure is a ⁇ -ray direct detection signal by an avalanche photodiode.
  • the radiation detector 10 was able to detect 0.66 MeV ⁇ rays from a 137 Cs radiation source with high sensitivity by using an avalanche photodiode as the light receiving element 14.
  • FIG. 14 shows detection of 1.8 MeV ⁇ -rays from a 90 Sr radiation source using the radiation detector 10 composed of the scintillator 13 (Lu X0.997 Yb 0.003 ) 2 O 3 of Example 1 and an avalanche photodiode. It is a figure which shows energy wave height distribution at the time. As shown in FIG. 14, the radiation detector 10 was able to detect the 1.8 MeV ⁇ -ray from the 90 Sr radiation source with high sensitivity by using an avalanche photodiode as the light receiving element 14.
  • FIG. 15 shows detection of 5.5 MeV ⁇ rays from a 241 Am radiation source using the radiation detector 10 comprising the scintillator 13 (Lu X0.997 Yb 0.003 ) 2 O 3 of Example 1 and an avalanche photodiode. It is a figure which shows energy wave height distribution at the time.
  • the radiation detector 10 can detect the 5.5 MeV ⁇ ray from the 241 Am radiation source with high sensitivity by using an avalanche photodiode as the light receiving element 14.
  • FIG. 16 shows a 5.5 MeV ⁇ ray from a 241 Am radiation source using the radiation detector 10 composed of the scintillator 13 (Lu X0.997 Yb 0.003 ) 2 O 3 and Geiger mode avalanche photodiode of Example 1. The energy wave height distribution at the time of detection is shown.
  • the radiation detector 10 was able to detect the 5.5 MeV ⁇ ray from the 241 Am radiation source with high sensitivity by using a Geiger mode avalanche photodiode as the light receiving element 14.
  • FIG. 17 shows a 1.8 MeV ⁇ ray from a 90 Sr radiation source using the radiation detector 10 composed of the scintillator 13 (Lu X0.997 Yb 0.003 ) 2 O 3 and Geiger mode avalanche photodiode of Example 1. The energy wave height distribution at the time of detection is shown.
  • the radiation detector 10 was able to detect the 1.8 MeV ⁇ -ray from the 90 Sr radiation source with high sensitivity by using a Geiger mode avalanche photodiode as the light receiving element 14.
  • the characteristics of the radiation detector 10 were the same even if the light receiving element 14 was replaced with IIT and CCD. From the above measurement, in the scintillator 13 (Lu X0.997 Yb 0.003 ) 2 O 3 of Example 1, the light receiving peak wavelength is 360 to 370 nm, the light emission amount is 1500 photons / MeV, and the fluorescence lifetime is about 1 ns. there were.
  • Example 4 a fluorescent material having a blending ratio of (Lu 0.99 Sc 0.007 Yb 0.003 ) 2 O 3 was produced.
  • Lutetium oxide raw material powder and ytterbium oxide raw material powder manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99%, BET specific surface area value 2.7 m 2 / g) prepared in Example 1 and scandium oxide raw material powder (Shin-Etsu Chemical Co., Ltd.) Co., Ltd., purity 99.99%, BET specific surface area value 3.5 m 2 / g) was weighed so as to have a composition ratio of (Lu 0.99 Sc 0.007 Yb 0.003 ) 2 O 3 , and then mixed to prepare a raw material A mixed powder was obtained.
  • the raw material mixed powder was treated in the same manner as in Example 1 and vacuum baked at 1650 ° C. for 10 hours to obtain a transparent polycrystalline ceramic composed of (Lu 0.99 Sc 0.007 Yb 0.003 ) 2 O 3 of Example 4. Produced. Next, a radiation detector 10 using this transparent polycrystalline ceramic was manufactured. The radiation detector 10 was incorporated in the radiation inspection apparatus 20, and the characteristics of the scintillator 13 were measured in the same manner as in Example 3.
  • the light reception peak wavelength was 360 to 370 nm
  • the light emission amount when irradiated with ⁇ rays was 1800 photons / MeV
  • the fluorescence lifetime was about 1.5 ns.
  • Example 5 a fluorescent material having a blending ratio of (Lu 0.99 Y 0.007 Yb 0.003 ) 2 O 3 was produced.
  • the lutetium oxide raw material powder and the yttrium oxide raw material powder (manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99%, BET specific surface area value 4.5 m 2 / g) prepared in Example 1 and the ytterbium oxide raw material powder (Shin-Etsu Chemical Co., Ltd.) Co., Ltd., purity 99.99%, BET specific surface area value 2.7 m 2 / g) was weighed so as to have a composition ratio of (Lu 0.99 Y 0.007 Yb 0.003 ) 2 O 3 , then mixed and used as a raw material A mixed powder was obtained.
  • the raw material mixed powder was treated in the same manner as in Example 1 and vacuum baked at 1650 ° C. for 10 hours to obtain a transparent polycrystalline ceramic composed of (Lu 0.99 Y 0.007 Yb 0.003 ) 2 O 3 of Example 5. Produced. Next, a radiation detector 10 using this transparent polycrystalline ceramic was manufactured. The radiation detector 10 was incorporated in the radiation inspection apparatus 20, and the characteristics of the scintillator 13 were measured in the same manner as in Example 3.
  • the light receiving peak wavelength was 360 to 370 nm
  • the light emission amount was 1400 photons / MeV
  • the fluorescence lifetime was about 1 ns.
  • Example 6 a fluorescent material having a blending ratio of (Lu 0.99 Gd 0.007 Yb 0.003 ) 2 O 3 was produced.
  • Lutetium oxide raw material powder and ytterbium oxide raw material powder manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99%, BET specific surface area value 2.7 m 2 / g) and gadolinium oxide raw material powder (Shin-Etsu Chemical Co., Ltd.) prepared in Example 1 (Made by Co., Ltd., purity 99.99%, BET specific surface area value 4.3 m 2 / g) was weighed so as to have a composition ratio of (Lu 0.99 Gd 0.007 Yb 0.003 ) 2 O 3 , then mixed and used as a raw material A mixed powder was obtained.
  • This raw material mixed powder was treated in the same manner as in Example 1 and vacuum baked at 1650 ° C. for 10 hours to produce scintillator 13 made of (Lu 0.99 Gd 0.007 Yb 0.003 ) 2 O 3 of Example 6.
  • the radiation detector 10 using this scintillator 13 was manufactured.
  • the radiation detector 10 was incorporated in the radiation inspection apparatus 20, and the characteristics of the scintillator 13 were measured in the same manner as in Example 3.
  • the light receiving peak wavelength was 360 to 370 nm
  • the light emission amount was 1500 photons / MeV
  • the fluorescence lifetime was about 1.5 ns.
  • Example 7 a fluorescent material having a blending ratio of (Lu 0.99 La 0.007 Yb 0.003 ) 2 O 3 was produced.
  • the lutetium oxide raw material powder and the lanthanum oxide raw material powder (manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99%, BET specific surface area value 3.8 m 2 / g) prepared in Example 1 and ytterbium oxide raw material powder (Shin-Etsu Chemical Co., Ltd.) Co., Ltd., purity 99.99%, BET specific surface area value 2.7 m 2 / g) was weighed so as to have a composition ratio of (Lu 0.99 La 0.007 Yb 0.003 ) 2 O 3 , and then mixed to prepare a raw material A mixed powder was obtained.
  • This raw material mixed powder was treated in the same manner as in Example 1 and vacuum baked at 1650 ° C. for 10 hours to produce scintillator 13 made of (Lu 0.99 La 0.007 Yb 0.003 ) 2 O 3 of Example 6.
  • the radiation detector 10 using this scintillator 13 was manufactured.
  • the radiation detector 10 was incorporated in the radiation inspection apparatus 20, and the characteristics of the scintillator 13 were measured in the same manner as in Example 3.
  • the light receiving peak wavelength was 360 to 370 nm
  • the light emission amount was 1000 photons / MeV
  • the fluorescence lifetime was about 1.5 ns.
  • Example 8 a fluorescent material having a compounding ratio of (Lu 0.99 Sc 0.003 Y 0.004 Yb 0.003 ) 2 O 3 was produced.
  • the lutetium oxide raw material powder and scandium oxide raw material powder (manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99%, BET specific surface area value 3.5 m 2 / g) prepared in Example 1 and yttrium oxide raw material powder (Shin-Etsu Chemical Co., Ltd.) Manufactured by Co., Ltd., purity 99.99%, BET specific surface area value 4.5 m 2 / g) and ytterbium oxide raw material powder (manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99%, BET specific surface area value 2.7 m 2) / G) was weighed so as to have a composition ratio of (Lu 0.99 Sc 0.003 Y 0.004 Yb 0.003 ) 2 O 3 and then mixed to
  • the raw material mixed powder is treated in the same manner as in Example 1 and vacuum baked at 1650 ° C. for 10 hours to produce the scintillator 13 made of (Lu 0.99 Sc 0.003 Y 0.004 Yb 0.003 ) 2 O 3 of Example 6. did.
  • the radiation detector 10 using this scintillator 13 was manufactured.
  • the radiation detector 10 was incorporated in the radiation inspection apparatus 20, and the characteristics of the scintillator 13 were measured in the same manner as in Example 3.
  • the light receiving peak wavelength was 360 to 370 nm
  • the light emission amount was 1700 photons / MeV
  • the fluorescence lifetime was about 1.5 ns.
  • Example 9 a fluorescent material having a blending ratio of (Lu 0.99 Sc 0.003 Gd 0.004 Yb 0.003 ) 2 O 3 was produced.
  • Lutetium oxide raw material powder and scandium oxide raw material powder (manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99%, BET specific surface area value 3.5 m 2 / g) and gadolinium oxide raw material powder (Shin-Etsu Chemical Co., Ltd.) produced in Example 1 Manufactured by Co., Ltd., purity 99.99%, BET specific surface area value 4.3 m 2 / g) and ytterbium oxide raw material powder (manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99%, BET specific surface area value 2.7 m 2) / G) was weighed so as to have a composition ratio of (Lu 0.99 Sc 0.003 Gd 0.004 Yb 0.003 ) 2 O 3 and mixed to obtain a
  • the raw material mixed powder is treated in the same manner as in Example 1 and vacuum baked at 1650 ° C. for 10 hours to produce the scintillator 13 made of (Lu 0.99 Sc 0.003 Gd 0.004 Yb 0.003 ) 2 O 3 of Example 9. did.
  • the radiation detector 10 using this scintillator 13 was manufactured.
  • the radiation detector 10 was incorporated in the radiation inspection apparatus 20, and the characteristics of the scintillator 13 were measured in the same manner as in Example 3.
  • the light receiving peak wavelength was 360 to 370 nm
  • the light emission amount was 1600 photons / MeV
  • the fluorescence lifetime was about 1.5 ns.
  • Example 10 a fluorescent material having a blending ratio of (Lu 0.99 Sc 0.005 La 0.002 Yb 0.003 ) 2 O 3 was produced.
  • Lutetium oxide raw material powder and scandium oxide raw material powder (manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99%, BET specific surface area value 3.5 m 2 / g) and lanthanum oxide raw material powder (Shin-Etsu Chemical Industry) produced in Example 1 Manufactured by Co., Ltd., purity 99.99%, BET specific surface area value 3.8 m 2 / g) and ytterbium oxide raw material powder (manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99%, BET specific surface area value 2.7 m 2) / G) was weighed so as to have a composition ratio of (Lu 0.99 Sc 0.005 La 0.002 Yb 0.003 ) 2 O 3 and mixed to obtain a raw material mixed powder.
  • This raw material mixed powder is treated in the same manner as in Example 1 and vacuum baked at 1650 ° C. for 10 hours to produce the scintillator 13 made of (Lu 0.99 Sc 0.005 La 0.002 Yb 0.003 ) 2 O 3 of Example 10. did.
  • the radiation detector 10 using this scintillator 13 was manufactured.
  • the radiation detector 10 was incorporated in the radiation inspection apparatus 20, and the characteristics of the scintillator 13 were measured in the same manner as in Example 3.
  • the light receiving peak wavelength was 360 to 370 nm
  • the light emission amount was 1400 photons / MeV
  • the fluorescence lifetime was about 1.7 ns.
  • Example 11 a fluorescent material having a blending ratio of (Lu 0.99 Y 0.004 Gd 0.003 Yb 0.003 ) 2 O 3 was produced.
  • the lutetium oxide raw material powder and yttrium oxide raw material powder (manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99%, BET specific surface area value 4.5 m 2 / g) and gadolinium oxide raw material powder (Shin-Etsu Chemical Industry) produced in Example 1 Manufactured by Co., Ltd., purity 99.99%, BET specific surface area value 4.3 m 2 / g) and ytterbium oxide raw material powder (manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99%, BET specific surface area value 2.7 m 2) / G) was weighed so as to have a composition ratio of (Lu 0.99 Y 0.004 Gd 0.003 Yb 0.003 ) 2 O 3 and then mixed to
  • the raw material mixed powder is treated in the same manner as in Example 1 and vacuum baked at 1650 ° C. for 10 hours to produce the scintillator 13 made of (Lu 0.99 Y 0.004 Gd 0.003 Yb 0.003 ) 2 O 3 of Example 11. did.
  • the radiation detector 10 using this scintillator 13 was manufactured.
  • the radiation detector 10 was incorporated in the radiation inspection apparatus 20, and the characteristics of the scintillator 13 were measured in the same manner as in Example 3.
  • the light receiving peak wavelength was 360 to 370 nm
  • the light emission amount was 1500 photons / MeV
  • the fluorescence lifetime was about 1 ns.
  • Example 12 a fluorescent material having a blending ratio of (Lu 0.99 Y 0.005 La 0.02 Yb 0.003 ) 2 O 3 was produced.
  • the lutetium oxide raw material powder and the yttrium oxide raw material powder (manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99%, BET specific surface area value 4.5 m 2 / g) and lanthanum oxide raw material powder (Shin-Etsu Chemical Industry) produced in Example 1 Manufactured by Co., Ltd., purity 99.99%, BET specific surface area value 3.8 m 2 / g) and ytterbium oxide raw material powder (manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99%, BET specific surface area value 2.7 m 2) / G) was weighed so as to have a composition ratio of (Lu 0.99 Y 0.005 La 0.02 Yb 0.003 ) 2 O 3 and mixed to obtain a raw
  • This raw material mixed powder is treated in the same manner as in Example 1 and vacuum baked at 1650 ° C. for 10 hours to produce the scintillator 13 made of (Lu 0.99 Y 0.005 La 0.02 Yb 0.003 ) 2 O 3 of Example 12. did.
  • the radiation detector 10 using this scintillator 13 was manufactured.
  • the radiation detector 10 was incorporated in the radiation inspection apparatus 20, and the characteristics of the scintillator 13 were measured in the same manner as in Example 3.
  • the light receiving peak wavelength was 360 to 370 nm
  • the light emission amount was 1400 photons / MeV
  • the fluorescence lifetime was about 1 ns.
  • Example 13 a fluorescent material having a blending ratio of (Lu 0.99 Gd 0.005 La 0.002 Yb 0.003 ) 2 O 3 was produced.
  • the lutetium oxide raw material powder and gadolinium oxide raw material powder (manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99%, BET specific surface area value 4.3 m 2 / g) and lanthanum oxide raw material powder (Shin-Etsu Chemical Industry) produced in Example 1 Manufactured by Co., Ltd., purity 99.99%, BET specific surface area value 3.8 m 2 / g) and ytterbium oxide raw material powder (manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99%, BET specific surface area value 2.7 m 2) / G) was weighed so as to have a composition ratio of (Lu 0.99 Gd 0.005 La 0.002 Yb 0.003 ) 2 O 3 and mixed to obtain a raw
  • This raw material mixed powder is treated in the same manner as in Example 1 and vacuum baked at 1650 ° C. for 10 hours to produce the scintillator 13 made of (Lu 0.99 Gd 0.005 La 0.002 Yb 0.003 ) 2 O 3 of Example 13. did.
  • the radiation detector 10 using this scintillator 13 was manufactured.
  • the radiation detector 10 was incorporated in the radiation inspection apparatus 20, and the characteristics of the scintillator 13 were measured in the same manner as in Example 3.
  • the light receiving peak wavelength was 360 to 370 nm
  • the light emission amount was 1500 photons / MeV
  • the fluorescence lifetime was about 1 ns.
  • Table 2 summarizes the emission peak wavelength, emission amount, and fluorescence lifetime when the radiation detector 10 using the scintillators 13 of Examples 3 to 13 is irradiated with ⁇ rays.
  • Example 14 a fluorescent material having a blending ratio of (Gd 0.997 Yb 0.003 ) 2 O 3 was produced.
  • the single crystal for the scintillator 13 was produced using a micro pulling method.
  • As the melt a mixture of oxide powders of Gd 2 O 3 and Yb 2 O 3 so that the single crystal has a composition ratio of (Gd 0.997 Yb 0.003 ) 2 O 3 was used. That is, an oxide powder raw material having a purity of 99.99% was prepared, and Re metal was used as a crucible.
  • As the atmosphere a mixed gas composed of Ar (97%) gas and H 2 (3%) gas was used.
  • a single crystal having the same composition as the single crystal to be produced was cut in the [111] direction to obtain a seed crystal.
  • the solid-liquid interface was observed with a CCD camera to determine the appropriate temperature and crystal production rate.
  • a typical condition for the crystal production speed was 0.05 to 0.1 mm / min.
  • the radiation detector 10 using the scintillator 13 made of (Gd 0.997 Yb 0.003 ) 2 O 3 was manufactured and incorporated in the radiation inspection apparatus 20, and the characteristics of the scintillator 13 were measured in the same manner as in Example 3.
  • the light reception peak wavelength was 360 to 370 nm
  • the light emission amount was 1600 photons / MeV
  • the fluorescence lifetime was about 1 ns.
  • Lu in Example 3 is replaced with Gd, but the received light peak wavelength is 360 to 370 nm as in Example 3.
  • the light emission amount and fluorescence lifetime of Example 14 were the same as those of Example 3.
  • Example 15 a fluorescent material having a blending ratio of (Gd 0.947 Sc 0.05 Yb 0.003 ) 2 O 3 was produced.
  • the radiation detector 10 using the scintillator 13 made of (Gd 0.947 Sc 0.05 Yb 0.003 ) 2 O 3 is manufactured in the same manner as in the fourteenth embodiment, and is incorporated in the radiation inspection apparatus 20.
  • the characteristics of the scintillator 13 were measured.
  • the received light peak wavelength was 360 to 370 nm
  • the light emission amount was 1800 photons / MeV
  • the fluorescence lifetime was about 1.5 ns.
  • Example 16 a fluorescent material having a blending ratio of (Gd 0.947 Y 0.05 Yb 0.003 ) 2 O 3 was produced.
  • the radiation detector 10 using the scintillator 13 made of (Gd 0.947 Y 0.05 Yb 0.003 ) 2 O 3 is manufactured in the same manner as in the fourteenth embodiment, incorporated in the radiation inspection apparatus 20, and the same as in the third embodiment. The characteristics of the scintillator 13 were measured.
  • the light receiving peak wavelength was 360 to 370 nm
  • the light emission amount was 1600 photons / MeV
  • the fluorescence lifetime was about 1 ns.
  • Example 17 a fluorescent material having a blending ratio of (Gd 0.947 La 0.05 Yb 0.003 ) 2 O 3 was produced.
  • the radiation detector 10 using the scintillator 13 made of (Gd 0.947 La 0.05 Yb 0.003 ) 2 O 3 is manufactured and incorporated in the radiation inspection apparatus 20, and the same as in Example 3.
  • the characteristics of the scintillator 13 were measured.
  • the light reception peak wavelength was 360 to 370 nm
  • the light emission amount was 1200 photons / MeV
  • the fluorescence lifetime was about 1 ns.
  • Table 3 summarizes the emission peak wavelength, emission amount, and fluorescence lifetime when the radiation detector 10 using the scintillators 13 of Examples 14 to 17 is irradiated with ⁇ rays.
  • Example 18 a fluorescent material with a blending ratio of (La 0.997 Yb 0.003 ) 2 O 3 was produced.
  • polycrystal was used as in Example 1.
  • the radiation detector 10 using the scintillator 13 made of (La 0.997 Yb 0.003 ) 2 O 3 was manufactured, incorporated in the radiation inspection apparatus 20, and the characteristics of the scintillator 13 were measured in the same manner as in Example 3.
  • the received light peak wavelength was 360 to 370 nm
  • the light emission amount was 200 photons / MeV
  • the fluorescence lifetime was about 1 ns.
  • Example 14 Lu in Example 3 is replaced with La, but the received light peak wavelength is 360 to 370 nm as in Example 3. Further, the light emission amount of Example 14 was about 13% of Example 3, but the fluorescence lifetime was the same as that of Example 3.
  • Example 19 a fluorescent material having a blending ratio of (La 0.947 Sc 0.05 Yb 0.003 ) 2 O 3 was produced.
  • the radiation detector 10 using the scintillator 13 made of (La 0.947 Sc 0.05 Yb 0.003 ) 2 O 3 was manufactured and incorporated in the radiation inspection apparatus 20, and the characteristics of the scintillator 13 were measured in the same manner as in Example 3. did.
  • the light receiving peak wavelength was 360 to 370 nm
  • the light emission amount was 400 photons / MeV
  • the fluorescence lifetime was about 1.5 ns.
  • Example 20 a fluorescent material having a blending ratio of (La 0.947 Y 0.05 Yb 0.003 ) 2 O 3 was produced.
  • the radiation detector 10 using the scintillator 13 made of (La 0.947 Y 0.05 Yb 0.003 ) 2 O 3 was manufactured and incorporated in the radiation inspection apparatus 20, and the characteristics of the scintillator 13 were measured in the same manner as in Example 3. did.
  • the light reception peak wavelength was 360 to 370 nm
  • the light emission amount was 300 photons / MeV
  • the fluorescence lifetime was about 1 ns.
  • Example 21 a fluorescent material having a blending ratio of (La 0.947 Gd 0.05 Yb 0.003 ) 2 O 3 was produced.
  • the radiation detector 10 using the scintillator 13 made of (La 0.947 Gd 0.05 Yb 0.003 ) 2 O 3 was manufactured and incorporated in the radiation inspection apparatus 20, and the characteristics of the scintillator 13 were measured in the same manner as in Example 3. did.
  • the light reception peak wavelength was 360 to 370 nm
  • the light emission amount was 300 photons / MeV
  • the fluorescence lifetime was about 1 ns.
  • Table 4 summarizes the emission peak wavelength, emission amount, and fluorescence lifetime when the radiation detector 10 using the scintillators 13 of Examples 18 to 21 is irradiated with ⁇ rays.
  • Example 22 a fluorescent material with a blending ratio of (Sc 0.997 Yb 0.003 ) 2 O 3 was produced.
  • a scandium oxide raw material powder was produced (see Patent Document 2, paragraph [0040]). Scandium oxide having a purity of 99.9% or more and Si of 5 ppm was dissolved in hydrochloric acid to prepare an aqueous scandium chloride solution having a concentration of 0.25 M (mol ⁇ dm ⁇ 3 ). 500 ml of this solution was placed in a polytetrafluoroethylene beaker and stirred.
  • a 0.5M (mol ⁇ dm ⁇ 3 ) ammonium hydrogen carbonate solution was dropped into an aqueous scandium chloride solution at a rate of 5 ml / min until pH 8.0 was reached, followed by curing at room temperature for 10 days. . After curing, filtration and washing with ultrapure water were repeated several times, and then placed in a dryer at 150 ° C. and dried for 2 days.
  • the obtained precursor powder was put into an alumina crucible and calcined (1250 ° C. ⁇ 3 hours) in an electric furnace to prepare a scandium oxide raw material powder having an average primary particle size of 0.35 ⁇ m.
  • the scandium oxide raw material powder and the ytterbium oxide raw material powder (manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99%, BET specific surface area value 2.7 m 2 / g) are (Sc 0.997 Yb 0.003 ) 2 O 3
  • the raw material mixed powder was treated in the same manner as in Example 1 and vacuum baked at 1700 ° C. for 5 hours to produce a scintillator 13 made of (Sc 0.997 Yb 0.003 ) 2 O 3 of Example 22.
  • the radiation detector 10 using this scintillator 13 was manufactured.
  • the radiation detector 10 was incorporated in the radiation inspection apparatus 20, and the characteristics of the scintillator 13 were measured in the same manner as in Example 3.
  • the light receiving peak wavelength was 360 to 370 nm
  • the light emission amount was 2000 photons / MeV
  • the fluorescence lifetime was about 2 ns.
  • Lu in Example 3 is replaced with Sc, but the received light peak wavelength is 360 to 370 nm as in Example 3.
  • the light emission amount of Example 22 was about 133% of Example 3, but the fluorescence lifetime was 2 ns, about twice that of Example 3.
  • Example 23 a fluorescent material having a blending ratio of (Sc 0.99 Y 0.007 Yb 0.003 ) 2 O 3 was produced.
  • Scandium oxide raw material powder and yttrium oxide raw material powder produced by Example 22 manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99%, BET specific surface area value 4.5 m 2 / g) and ytterbium oxide (Shin-Etsu Chemical Co., Ltd.) ), Purity 99.99%, BET specific surface area value 2.7 m 2 / g) was weighed so as to have a composition ratio of (Sc 0.99 Y 0.007 Yb 0.003 ) 2 O 3 , and mixed to mix the raw materials Powdered.
  • the raw material mixed powder was treated in the same manner as in Example 1 and vacuum baked at 1700 ° C. for 5 hours to produce a scintillator 13 made of (Sc 0.99 Y 0.007 Yb 0.003 ) 2 O 3 of Example 23.
  • the radiation detector 10 using this scintillator 13 was manufactured.
  • the radiation detector 10 was incorporated in the radiation inspection apparatus 20, and the characteristics of the scintillator 13 were measured in the same manner as in Example 3.
  • the light receiving peak wavelength was 360 to 370 nm
  • the light emission amount was 1800 photons / MeV
  • the fluorescence lifetime was about 1.8 ns.
  • Example 24 a fluorescent material having a blending ratio of (Sc 0.99 Gd 0.007 Yb 0.003 ) 2 O 3 was produced.
  • Scandium oxide raw material powder and yttrium oxide raw material powder produced by Example 22 manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99%, BET specific surface area value 4.5 m 2 / g) and ytterbium oxide raw material powder (Shin-Etsu Chemical Co., Ltd.) (Made by Co., Ltd., purity 99.99%, BET specific surface area value 2.7 m 2 / g) was weighed so as to have a composition ratio of (Sc 0.99 Gd 0.007 Yb 0.003 ) 2 O 3 and mixed.
  • Raw material mixed powder was used.
  • the raw material mixed powder was treated in the same manner as in Example 1 and vacuum baked at 1700 ° C. for 5 hours to produce the scintillator 13 made of (Sc 0.99 Gd 0.007 Yb 0.003 ) 2 O 3 of Example 24.
  • the radiation detector 10 using this scintillator 13 was manufactured.
  • the radiation detector 10 was incorporated in the radiation inspection apparatus 20, and the characteristics of the scintillator 13 were measured in the same manner as in Example 3.
  • the light receiving peak wavelength was 360 to 370 nm
  • the light emission amount was 1800 photons / MeV
  • the fluorescence lifetime was about 2 ns.
  • Example 25 a fluorescent material having a blending ratio of (Sc 0.99 Gd 0.007 Yb 0.003 ) 2 O 3 was produced.
  • Scandium oxide raw material powder and yttrium oxide raw material powder produced by Example 22 manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99%, BET specific surface area value 4.5 m 2 / g) and ytterbium oxide raw material powder (Shin-Etsu Chemical Co., Ltd.) (Made by Co., Ltd., purity 99.99%, BET specific surface area value 2.7 m 2 / g) was weighed so as to have a composition ratio of (Sc 0.99 Gd 0.007 Yb 0.003 ) 2 O 3 and mixed.
  • Raw material mixed powder was used.
  • the raw material mixed powder was treated in the same manner as in Example 1 and vacuum baked at 1700 ° C. for 5 hours to produce the scintillator 13 made of (Sc 0.99 Gd 0.007 Yb 0.003 ) 2 O 3 of Example 25.
  • the radiation detector 10 using this scintillator 13 was manufactured.
  • the radiation detector 10 was incorporated in the radiation inspection apparatus 20, and the characteristics of the scintillator 13 were measured in the same manner as in Example 3.
  • the light receiving peak wavelength was 360 to 370 nm
  • the light emission amount was 1600 photons / MeV
  • the fluorescence lifetime was about 2 ns.
  • Table 5 summarizes the emission peak wavelength, emission amount, and fluorescence lifetime when the radiation detector 10 using the scintillators 13 of Examples 22 to 25 is irradiated with ⁇ rays.
  • Example 26 a fluorescent material having a blending ratio of (Y 0.997 Yb 0.003 ) 2 O 3 was produced.
  • an yttrium oxide raw material powder was prepared, an average primary particle size of 0.3 ⁇ m, a purity of 99.99, based on the technique of JP-A-11-157933. 9% or more of Si 3 wtppm yttrium oxide raw material powder was produced.
  • an aqueous solution of yttrium nitrate, an aqueous solution of urea, and an aqueous solution of ammonium sulfate were mixed to give a yttrium: urea: ammonium sulfate molar ratio of 1: 6: 1 and hydrothermally reacted in an autoclave at 125 ° C. for 2 hours. Carbonate was obtained. The obtained carbonate was washed with pure water and dried. Next, this dry powder was calcined at 1200 ° C. for 3 hours in an air atmosphere using an alumina crucible to obtain an yttrium oxide raw material powder.
  • the above yttrium oxide raw material powder and ytterbium oxide raw material powder (manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99%, BET specific surface area value 2.7 m 2 / g) are used as (Y 0.997 Yb 0.003 ) 2 O 3
  • This raw material mixed powder was treated in the same manner as in Example 1 and vacuum baked at 1600 ° C. for 10 hours to produce scintillator 13 made of (Y 0.997 Yb 0.003 ) 2 O 3 of Example 26.
  • the radiation detector 10 using this scintillator 13 was manufactured.
  • the radiation detector 10 was incorporated in the radiation inspection apparatus 20, and the characteristics of the scintillator 13 were measured in the same manner as in Example 3.
  • the light receiving peak wavelength was 360 to 370 nm
  • the light emission amount was 200 photons / MeV
  • the fluorescence lifetime was about 1 ns.
  • Lu in Example 3 is replaced with Y, but the received light peak wavelength is 360 to 370 nm as in Example 3.
  • the light emission amount of Example 22 was about 13% of Example 3, but the fluorescence lifetime was 1 ns, the same as that of Example 3.
  • Example 27 a fluorescent material having a blending ratio of (Y 0.99 Sc 0.007 Yb 0.003 ) 2 O 3 was produced.
  • the yttrium oxide raw material powder and scandium oxide raw material powder produced by Example 26 (manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99%, BET specific surface area value 3.5 m 2 / g) and ytterbium oxide (Shin-Etsu Chemical Co., Ltd.
  • the light receiving peak wavelength was 360 to 370 nm
  • the light emission amount was 250 photons / MeV
  • the fluorescence lifetime was about 2 ns.
  • Example 28 a fluorescent material having a blending ratio of (Y 0.99 Gd 0.007 Yb 0.003 ) 2 O 3 was produced.
  • Yttrium oxide raw material powder and gadolinium oxide raw material powder manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99%, BET specific surface area value 4.3 m 2 / g) prepared in Example 26 and ytterbium oxide raw material powder (Shin-Etsu Chemical Co., Ltd.) (Made by Co., Ltd., purity 99.99%, BET specific surface area value 2.7 m 2 / g) was weighed so as to have a composition ratio of (Y 0.99 Gd 0.007 Yb 0.003 ) 2 O 3 and mixed.
  • Raw material mixed powder was used.
  • the raw material mixed powder was treated in the same manner as in Example 1 and vacuum baked at 1600 ° C. for 10 hours to produce the scintillator 13 made of (Y 0.99 Gd 0.007 Yb 0.003 ) 2 O 3 of Example 28.
  • the radiation detector 10 using this scintillator 13 was manufactured.
  • the radiation detector 10 was incorporated in the radiation inspection apparatus 20, and the characteristics of the scintillator 13 were measured in the same manner as in Example 3.
  • the light reception peak wavelength was 360 to 370 nm
  • the light emission amount was 300 photons / MeV
  • the fluorescence lifetime was about 1.5 ns.
  • Example 29 a fluorescent material having a blending ratio of (Y 0.995 La 0.002 Yb 0.003 ) 2 O 3 was produced.
  • Yttrium oxide raw material powder and lanthanum oxide raw material powder manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99%, BET specific surface area value 3.8 m 2 / g) prepared in Example 26 and ytterbium oxide raw material powder (Shin-Etsu Chemical Co., Ltd.) (Made by Co., Ltd., purity 99.99%, BET specific surface area value 2.7 m 2 / g) was weighed so as to have a composition ratio of (Y 0.995 La 0.002 Yb 0.003 ) 2 O 3 and mixed.
  • Raw material mixed powder was used.
  • the raw material mixed powder was treated in the same manner as in Example 1 and vacuum baked at 1600 ° C. for 10 hours to produce the scintillator 13 made of (Y 0.995 La 0.002 Yb 0.003 ) 2 O 3 of Example 29.
  • the radiation detector 10 using this scintillator 13 was manufactured.
  • the radiation detector 10 was incorporated in the radiation inspection apparatus 20, and the characteristics of the scintillator 13 were measured in the same manner as in Example 3.
  • the light receiving peak wavelength was 360 to 370 nm
  • the light emission amount was 250 photons / MeV
  • the fluorescence lifetime was about 1.5 ns.
  • Example 30 a fluorescent material having a compounding ratio of (Y 0.99 Sc 0.004 Gd 0.003 Yb 0.003 ) 2 O 3 was produced.
  • Yttrium oxide raw material powder and scandium oxide raw material powder manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99%, BET specific surface area value 3.5 m 2 / g) and gadolinium oxide raw material powder (Shin-Etsu Chemical Co., Ltd.) produced in Example 26 Manufactured by Co., Ltd., purity 99.99%, BET specific surface area value 4.3 m 2 / g) and ytterbium oxide raw material powder (manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99%, BET specific surface area value 2.7 m 2) / G) was weighed so as to have a composition ratio of (Y 0.99 Sc 0.004 Gd 0.003 Yb 0.003 ) 2 O 3 and mixed to obtain a raw material mixed
  • the raw material mixed powder was treated in the same manner as in Example 1 and vacuum baked at 1600 ° C. for 10 hours to produce the scintillator 13 made of (Y 0.99 Sc 0.004 Gd 0.003 Yb 0.003 ) 2 O 3 of Example 30. did.
  • the radiation detector 10 using this scintillator 13 was manufactured.
  • the radiation detector 10 was incorporated in the radiation inspection apparatus 20, and the characteristics of the scintillator 13 were measured in the same manner as in Example 3.
  • the light receiving peak wavelength was 360 to 370 nm
  • the light emission amount was 500 photons / MeV
  • the fluorescence lifetime was about 1.5 ns.
  • Example 31 a fluorescent material having a blending ratio of (Y 0.99 Sc 0.005 La 0.002 Yb 0.003 ) 2 O 3 was produced.
  • Yttrium oxide raw material powder and scandium oxide raw material powder manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99%, BET specific surface area value 3.5 m 2 / g) prepared in Example 26 and lanthanum oxide raw material powder (Shin-Etsu Chemical Co., Ltd.) Manufactured by Co., Ltd., purity 99.99%, BET specific surface area value 3.8 m 2 / g) and ytterbium oxide raw material powder (manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99%, BET specific surface area value 2.7 m 2) / G) was weighed so as to have a composition ratio of (Y 0.99 Sc 0.005 La 0.002 Yb 0.003 ) 2 O 3 and mixed to obtain a raw material mixed powder.
  • the raw material mixed powder was treated in the same manner as in Example 1 and vacuum fired at 1600 ° C. for 10 hours to produce the scintillator 13 made of (Y 0.99 Sc 0.005 La 0.002 Yb 0.003 ) 2 O 3 of Example 31. .
  • the radiation detector 10 using this scintillator 13 was manufactured.
  • the radiation detector 10 was incorporated in the radiation inspection apparatus 20, and the characteristics of the scintillator 13 were measured in the same manner as in Example 3.
  • the light receiving peak wavelength was 360 to 370 nm
  • the light emission amount was 600 photons / MeV
  • the fluorescence lifetime was about 1.5 ns.
  • Example 32 a fluorescent material having a blending ratio of (Y 0.99 Gd 0.005 La 0.002 Yb 0.003 ) 2 O 3 was produced.
  • Yttrium oxide raw material powder and scandium oxide raw material powder manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99%, BET specific surface area value 3.5 m 2 / g) prepared in Example 26 and lanthanum oxide raw material powder (Shin-Etsu Chemical Co., Ltd.) Manufactured by Co., Ltd., purity 99.99%, BET specific surface area value 3.8 m 2 / g) and ytterbium oxide raw material powder (manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99%, BET specific surface area value 2.7 m 2) / G) was weighed so as to have a composition ratio of (Y 0.99 Gd 0.005 La 0.002 Yb 0.003 ) 2 O 3 and mixed to obtain a raw material
  • the raw material mixed powder was treated in the same manner as in Example 1 and vacuum baked at 1600 ° C. for 10 hours to produce the scintillator 13 made of (Y 0.99 Gd 0.005 La 0.002 Yb 0.003 ) 2 O 3 of Example 32. .
  • the radiation detector 10 using this scintillator 13 was manufactured.
  • the radiation detector 10 was incorporated in the radiation inspection apparatus 20, and the characteristics of the scintillator 13 were measured in the same manner as in Example 3.
  • the light receiving peak wavelength was 360 to 370 nm
  • the light emission amount was 500 photons / MeV
  • the fluorescence lifetime was about 1 ns.
  • Table 6 summarizes the emission peak wavelength, emission amount, and fluorescence lifetime when the radiation detector 10 using the scintillators 13 of Examples 26 to 32 is irradiated with ⁇ rays.
  • the composition of the scintillator 13 may be set as appropriate in consideration of the fluorescence emission amount and the fluorescence lifetime.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Structural Engineering (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Molecular Biology (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Measurement Of Radiation (AREA)
  • Luminescent Compositions (AREA)
  • Nuclear Medicine (AREA)

Abstract

La présente invention concerne : un matériau luminescent pour scintillateur, le matériau présentant une durée de fluorescence extrêmement courte de quelques subnanosecondes ; un scintillateur l'utilisant ; et un détecteur de rayonnement et un appareil d'inspection de rayonnement l'utilisant. Le matériau luminescent pour scintillateur est représenté par la formule chimique (R1-XYbX)2O3 (où R est au moins un élément choisi parmi les terres rares tels que Sc, Y et les lanthanides, et 0 < x < 0,1). Ce matériau luminescent pour scintillateur génère une fluorescence présentant une longueur d'onde de maximum d'émission située dans la plage de longueurs d'onde allant d'environ 300 nm à 600 nm après exposition à un rayonnement, absorbe moins dans la plage de longueurs d'onde allant de 300 nm à 530 nm qui correspond à cette longueur d'onde de maximum d'émission et est transparent. Le matériau luminescent pour scintillateur est polycristallin ou monocristallin. Le scintillateur est composé du matériau luminescent pour scintillateur décrit ci-dessus. Le détecteur de rayonnement (10) de l'invention comprend un scintillateur (13) et un élément récepteur de lumière (14) qui reçoit la fluorescence provenant du scintillateur (13).
PCT/JP2011/080076 2010-12-27 2011-12-26 Matériau luminescent pour scintillateur, scintillateur l'utilisant et détecteur de rayonnement et appareil d'inspection de rayonnement l'utilisant WO2012090936A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2010291327A JP2012136667A (ja) 2010-12-27 2010-12-27 シンチレータ用発光材料、それを用いたシンチレータ及びそれを用いた放射線検出器並びに放射線検査装置
JP2010-291327 2010-12-27

Publications (1)

Publication Number Publication Date
WO2012090936A1 true WO2012090936A1 (fr) 2012-07-05

Family

ID=46383039

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2011/080076 WO2012090936A1 (fr) 2010-12-27 2011-12-26 Matériau luminescent pour scintillateur, scintillateur l'utilisant et détecteur de rayonnement et appareil d'inspection de rayonnement l'utilisant

Country Status (2)

Country Link
JP (1) JP2012136667A (fr)
WO (1) WO2012090936A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110622039A (zh) * 2017-03-15 2019-12-27 德国史密斯海曼简化股份公司 用于检查系统的检测器和方法

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015531414A (ja) * 2012-09-11 2015-11-02 オーシャンズ キング ライティング サイエンス アンド テクノロジー シーオー．，エルティーディー ルテチウム酸化物発光材料、及び、その製造方法
JP2019082409A (ja) * 2017-10-31 2019-05-30 国立大学法人千葉大学 Ｐｅｔ装置用シンチレーター及びこれを用いたｐｅｔ装置

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5930882A (ja) * 1982-06-18 1984-02-18 ゼネラル・エレクトリツク・カンパニイ 希土類添加イツトリア−ガドリニアセラミツクシンチレ−タおよびその製法
JPS5930883A (ja) * 1982-06-18 1984-02-18 ゼネラル・エレクトリツク・カンパニイ 希土類添加イツトリア−ガドリニアセラミツクシンチレ−タおよびその製法
JPS6438491A (en) * 1982-06-18 1989-02-08 Gen Electric Rare earth metal element added yttria-gadonia ceramic scintillator
JPH06206769A (ja) * 1992-07-28 1994-07-26 Siemens Ag 希土類−オキシスルフィドの高密度シンチレーションセラミックの製法及びレントゲンコンピューター断層撮影用セラミック体
JP2000178547A (ja) * 1998-12-16 2000-06-27 Hitachi Metals Ltd セラミックスシンチレータ
JP2003277191A (ja) * 2002-03-26 2003-10-02 Japan Science & Technology Corp Ｙｂ混晶酸化物単結晶からなるシンチレータ用発光材料
JP2005095514A (ja) * 2003-09-26 2005-04-14 Hitachi Medical Corp 放射線検出器及びそれを用いたｘ線ｃｔ装置
JP2010122166A (ja) * 2008-11-21 2010-06-03 Tohoku Univ 放射線検出器および放射線検査装置
JP2010169673A (ja) * 2008-12-26 2010-08-05 Tohoku Univ 放射線検出器

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5930882A (ja) * 1982-06-18 1984-02-18 ゼネラル・エレクトリツク・カンパニイ 希土類添加イツトリア−ガドリニアセラミツクシンチレ−タおよびその製法
JPS5930883A (ja) * 1982-06-18 1984-02-18 ゼネラル・エレクトリツク・カンパニイ 希土類添加イツトリア−ガドリニアセラミツクシンチレ−タおよびその製法
JPS6438491A (en) * 1982-06-18 1989-02-08 Gen Electric Rare earth metal element added yttria-gadonia ceramic scintillator
JPH06206769A (ja) * 1992-07-28 1994-07-26 Siemens Ag 希土類−オキシスルフィドの高密度シンチレーションセラミックの製法及びレントゲンコンピューター断層撮影用セラミック体
JP2000178547A (ja) * 1998-12-16 2000-06-27 Hitachi Metals Ltd セラミックスシンチレータ
JP2003277191A (ja) * 2002-03-26 2003-10-02 Japan Science & Technology Corp Ｙｂ混晶酸化物単結晶からなるシンチレータ用発光材料
JP2005095514A (ja) * 2003-09-26 2005-04-14 Hitachi Medical Corp 放射線検出器及びそれを用いたｘ線ｃｔ装置
JP2010122166A (ja) * 2008-11-21 2010-06-03 Tohoku Univ 放射線検出器および放射線検査装置
JP2010169673A (ja) * 2008-12-26 2010-08-05 Tohoku Univ 放射線検出器

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110622039A (zh) * 2017-03-15 2019-12-27 德国史密斯海曼简化股份公司 用于检查系统的检测器和方法
CN110622039B (zh) * 2017-03-15 2023-10-24 德国史密斯海曼简化股份公司 用于检查系统的检测器和方法

Also Published As

Publication number Publication date
JP2012136667A (ja) 2012-07-19

Similar Documents

Publication Publication Date Title
JP5952746B2 (ja) シンチレータ用ガーネット型単結晶、及びこれを用いた放射線検出器
JP6644010B2 (ja) 向上した耐放射線性を有する多重ドープルテチウム系オキシオルトシリケートシンチレータ
JP5462515B2 (ja) 透明セラミックス及びその製造方法並びにその透明セラミックスを用いたデバイス
US8431042B2 (en) Solid state scintillator material, solid state scintillator, radiation detector, and radiation inspection apparatus
EP1043383B2 (fr) Luminophores et detecteurs de rayonnement et unites de tomodensitometrie formes a partir de ces luminophores
US5116560A (en) Method of forming rare earth oxide ceramic scintillator with ammonium dispersion of oxalate precipitates
CA2059915C (fr) Methode de production d&#39;un scintillateur ceramique d&#39;yttrium et de gadolinium comprenant une etape de coprecipitation d&#39;hydroxyde
US9183962B2 (en) Ceramic scintillator body and scintillation device
JP6037025B2 (ja) シンチレータ材料、放射線検出器及び放射線検査装置
CN112745845A (zh) 用于正电子发射断层摄影（pet）的基于立方石榴石组合物的陶瓷闪烁体
CN114561704A (zh) 大尺寸钨酸铋晶体的助熔剂生长方法及应用
WO2012090936A1 (fr) Matériau luminescent pour scintillateur, scintillateur l&#39;utilisant et détecteur de rayonnement et appareil d&#39;inspection de rayonnement l&#39;utilisant
JP2013043960A (ja) シンチレータ用ガーネット型結晶およびこれを用いる放射線検出器
JP4429444B2 (ja) シンチレータ、それを用いた放射線検出器及びｘ線ｃｔ装置
JP6188024B2 (ja) 発光体及び放射線検出器
JP5241979B2 (ja) セラミックシンチレータ材料とその製造方法、およびそれを用いた放射線検出器と放射線検査装置
JP6776671B2 (ja) 蛍光材料、セラミックシンチレータおよび放射線検出器、並びに蛍光材料の製造方法
Glodo et al. Novel high-stopping power scintillators for medical applications
Wang et al. ${\rm Lu} _ {2}{\rm SiO} _ {5}:{\rm Ce} $ Optical Ceramic Scintillator for PET
CN117721537A (zh) 竞争发光中心的稀土正硅酸盐闪烁材料及其制备方法和应用
KR101641946B1 (ko) 섬광체 및 이의 제조 방법
WO2024195455A1 (fr) Cristal de silicate de lutétium, sa méthode de production, matériau de scintillateur l&#39;utilisant, détecteur de rayonnement et dispositif d&#39;inspection de rayonnement
JP2013040274A (ja) シンチレータ用ガーネット型結晶およびこれを用いる放射線検出器
WO2021149670A1 (fr) Scintillateur et détecteur de radiation
JP2021143288A (ja) シンチレータ、放射線検知器、及び放射線画像システム

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 11853750

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 11853750

Country of ref document: EP

Kind code of ref document: A1