WO2019034043A1 - 用于慢化中子的缓速体 - Google Patents

用于慢化中子的缓速体 Download PDF

Info

Publication number
WO2019034043A1
WO2019034043A1 PCT/CN2018/100384 CN2018100384W WO2019034043A1 WO 2019034043 A1 WO2019034043 A1 WO 2019034043A1 CN 2018100384 W CN2018100384 W CN 2018100384W WO 2019034043 A1 WO2019034043 A1 WO 2019034043A1
Authority
WO
WIPO (PCT)
Prior art keywords
layer
substrate
container
retarding
surface treatment
Prior art date
Application number
PCT/CN2018/100384
Other languages
English (en)
French (fr)
Inventor
刘渊豪
Original Assignee
南京中硼联康医疗科技有限公司
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 南京中硼联康医疗科技有限公司 filed Critical 南京中硼联康医疗科技有限公司
Priority to EP18845737.8A priority Critical patent/EP3586921B1/en
Publication of WO2019034043A1 publication Critical patent/WO2019034043A1/zh
Priority to US16/561,234 priority patent/US11400316B2/en

Links

Images

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N5/00—Radiation therapy
    • A61N5/10—X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy
    • A61N5/103—Treatment planning systems
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N5/00—Radiation therapy
    • A61N5/10—X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy
    • A61N5/1077—Beam delivery systems
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N5/00—Radiation therapy
    • A61N5/10—X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N5/00—Radiation therapy
    • A61N5/10—X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy
    • A61N5/1048—Monitoring, verifying, controlling systems and methods
    • 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
    • C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
    • C04B35/553—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on fluorides
    • 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
    • C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/64—Burning or sintering processes
    • C04B35/645—Pressure sintering
    • 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
    • C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/64—Burning or sintering processes
    • C04B35/645—Pressure sintering
    • C04B35/6455—Hot isostatic pressing
    • 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
    • C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
    • C04B41/009—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone characterised by the material treated
    • 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
    • C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
    • C04B41/45—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements
    • C04B41/46—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements with organic materials
    • C04B41/48—Macromolecular compounds
    • C04B41/4838—Halogenated polymers
    • C04B41/4842—Fluorine-containing polymers
    • 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
    • C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
    • C04B41/45—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements
    • C04B41/46—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements with organic materials
    • C04B41/49—Compounds having one or more carbon-to-metal or carbon-to-silicon linkages ; Organo-clay compounds; Organo-silicates, i.e. ortho- or polysilicic acid esters ; Organo-phosphorus compounds; Organo-inorganic complexes
    • C04B41/4905—Compounds having one or more carbon-to-metal or carbon-to-silicon linkages ; Organo-clay compounds; Organo-silicates, i.e. ortho- or polysilicic acid esters ; Organo-phosphorus compounds; Organo-inorganic complexes containing silicon
    • C04B41/495—Compounds having one or more carbon-to-metal or carbon-to-silicon linkages ; Organo-clay compounds; Organo-silicates, i.e. ortho- or polysilicic acid esters ; Organo-phosphorus compounds; Organo-inorganic complexes containing silicon applied to the substrate as oligomers or polymers
    • C04B41/4961—Polyorganosiloxanes, i.e. polymers with a Si-O-Si-O-chain; "silicones"
    • 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
    • C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
    • C04B41/80—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone of only ceramics
    • C04B41/81—Coating or impregnation
    • C04B41/82—Coating or impregnation with organic materials
    • C04B41/83—Macromolecular 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
    • C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
    • C04B41/80—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone of only ceramics
    • C04B41/81—Coating or impregnation
    • C04B41/82—Coating or impregnation with organic materials
    • C04B41/84—Compounds having one or more carbon-to-metal of carbon-to-silicon linkages
    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21G—CONVERSION OF CHEMICAL ELEMENTS; RADIOACTIVE SOURCES
    • G21G1/00—Arrangements for converting chemical elements by electromagnetic radiation, corpuscular radiation or particle bombardment, e.g. producing radioactive isotopes
    • G21G1/04—Arrangements for converting chemical elements by electromagnetic radiation, corpuscular radiation or particle bombardment, e.g. producing radioactive isotopes outside nuclear reactors or particle accelerators
    • G21G1/06—Arrangements for converting chemical elements by electromagnetic radiation, corpuscular radiation or particle bombardment, e.g. producing radioactive isotopes outside nuclear reactors or particle accelerators by neutron irradiation
    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21K—TECHNIQUES FOR HANDLING PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES
    • G21K1/00—Arrangements for handling particles or ionising radiation, e.g. focusing or moderating
    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21K—TECHNIQUES FOR HANDLING PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES
    • G21K1/00—Arrangements for handling particles or ionising radiation, e.g. focusing or moderating
    • G21K1/10—Scattering devices; Absorbing devices; Ionising radiation filters
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
    • H05H3/00—Production or acceleration of neutral particle beams, e.g. molecular or atomic beams
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
    • H05H3/00—Production or acceleration of neutral particle beams, e.g. molecular or atomic beams
    • H05H3/06—Generating neutron beams
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N5/00—Radiation therapy
    • A61N5/10—X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy
    • A61N2005/1085—X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy characterised by the type of particles applied to the patient
    • A61N2005/109—Neutrons
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N5/00—Radiation therapy
    • A61N5/10—X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy
    • A61N2005/1092—Details
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N5/00—Radiation therapy
    • A61N5/10—X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy
    • A61N2005/1092—Details
    • A61N2005/1094—Shielding, protecting against radiation
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N5/00—Radiation therapy
    • A61N5/10—X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy
    • A61N2005/1092—Details
    • A61N2005/1095—Elements inserted into the radiation path within the system, e.g. filters or wedges
    • 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
    • C04B2235/3201—Alkali metal oxides or oxide-forming salts thereof
    • C04B2235/3203—Lithium 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
    • C04B2235/30—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
    • C04B2235/3205—Alkaline earth oxides or oxide forming salts thereof, e.g. beryllium oxide
    • C04B2235/3206—Magnesium oxides 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
    • C04B2235/30—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
    • C04B2235/3205—Alkaline earth oxides or oxide forming salts thereof, e.g. beryllium oxide
    • C04B2235/3208—Calcium oxide or oxide-forming salts thereof, e.g. lime
    • 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
    • C04B2235/3217—Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
    • 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
    • C04B2235/3296—Lead oxides, plumbates or oxide forming salts thereof, e.g. silver plumbate
    • 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
    • C04B2235/40—Metallic constituents or additives not added as binding phase
    • C04B2235/402—Aluminium
    • 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
    • C04B2235/656—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes characterised by specific heating conditions during heat treatment
    • C04B2235/6562—Heating rate
    • 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
    • C04B2235/656—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes characterised by specific heating conditions during heat treatment
    • C04B2235/6565—Cooling rate
    • 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
    • C04B2235/6582—Hydrogen containing atmosphere
    • 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
    • C04B2235/66—Specific sintering techniques, e.g. centrifugal sintering
    • C04B2235/666—Applying a current during sintering, e.g. plasma sintering [SPS], electrical resistance heating or pulse electric current sintering [PECS]
    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21G—CONVERSION OF CHEMICAL ELEMENTS; RADIOACTIVE SOURCES
    • G21G4/00—Radioactive sources
    • G21G4/02—Neutron sources

Definitions

  • the present invention relates to the field of medical devices, and in particular to a slowing body for moderating neutrons.
  • BNCT Boron Neutron Capture Therapy
  • boron-containing ( 10 B) drugs with 10 B(n, ⁇ ) 7 Li neutron capture and nuclear splitting reactions.
  • Two heavy charged particles of 4 He and 7 Li are produced. 1 and 2, which respectively show a schematic diagram of a boron neutron capture reaction and a 10 B(n, ⁇ ) 7 Li neutron capture nuclear reaction equation, the average energy of the two charged particles is about 2.33 MeV, which has high linearity.
  • Linear Energy Transfer (LET) short-range characteristics, the linear energy transfer and range of ⁇ particles are 150 keV/ ⁇ m and 8 ⁇ m, respectively, while the 7 Li heavy particles are 175 keV/ ⁇ m and 5 ⁇ m.
  • the total range of the two particles is approximately equivalent.
  • a cell size so the radiation damage caused by the organism can be limited to the cell level.
  • the boron-containing drug When the boron-containing drug is selectively accumulated in the tumor cells, with appropriate neutron source, it can cause too much damage to normal tissues. Under the premise, the purpose of locally killing tumor cells is achieved. High-energy neutron rays illuminate normal cells, which can damage DNA and cause side effects such as skin inflammation and radiation anemia, and white blood cells.
  • the ultrathermal neutron energy required for BNCT is low, while the average neutron energy produced by the neutron source is relatively high. It is necessary to moderately filter the neutrons in different energy regions before irradiating the patient.
  • the commonly used slowing materials are aluminum, aluminum fluoride, aluminum oxide, magnesium fluoride, calcium fluoride, etc., but metal fluorides such as aluminum fluoride and calcium fluoride may cause water absorption and even deliquescence after being exposed to the air for a long time. Physical and chemical changes affect the performance of the material, so there is a need for a method that effectively avoids the dehydration of the material.
  • a retarding body for moderating neutrons comprising a substrate and a surface treatment layer or a dry inert gas layer or vacuum coated on the surface of the substrate a layer; wherein the substrate is prepared from a powdered sintering device by a powder sintering device from a powder or a powder compact to a block, the moderated material comprising: 40-100% by weight of aluminum fluoride;
  • the surface treatment layer is a hydrophobic material; the surface treatment layer or a dry inert gas layer or a vacuum layer is used to insulate the water in the environment in which the substrate and the substrate are located.
  • the retarding body further includes a first container, the inert gas layer is located between the first container and the substrate, and the first container is for placing the substrate In an inert gas atmosphere.
  • the retarding body further includes a second container, the vacuum layer being located between the second container and the substrate, the second container being used to vacuum the substrate In the atmosphere.
  • the inert gas comprises: nitrogen, helium, neon, argon, helium, neon, or a combination thereof.
  • the moderator material comprises 50-90% by weight of aluminum fluoride and optionally one of lithium fluoride, aluminum, lead fluoride, aluminum oxide, calcium fluoride or magnesium fluoride. One or more mixed materials.
  • the moderator material comprises from 90 to 99.9% by weight of aluminum fluoride and optionally from 0.1 to 10% by weight of lithium fluoride.
  • the moderator material comprises: aluminum fluoride and lithium fluoride, and optionally one or more of aluminum, lead fluoride, aluminum oxide, calcium fluoride or magnesium fluoride. material.
  • the powder sintering apparatus is a hot press sintering apparatus or a discharge plasma sintering apparatus.
  • the powder sintering process is a hot press sintering process or a discharge plasma sintering process.
  • the surface treatment layer is a peelable surface treatment layer.
  • the surface treatment layer is selected from the group consisting of a hydrophobic organic polymer, a hydrophobic inorganic polymer, or a combination thereof.
  • the hydrophobic organic polymer is selected from the group consisting of organic fluoropolymers, silicone polymers, C2-20 substituted or unsubstituted olefinic polymers, C2-20 substituted or unsubstituted An alkyne polymer, or a combination thereof.
  • the hydrophobic material is a hydrophobic material having a contact angle ⁇ of 110 to 180° with water, preferably having a contact angle ⁇ of 120-180°, and more preferably a contact angle ⁇ of 130-180°.
  • the surface treatment layer is selected from the group consisting of a metal element, an alloy, a metal oxide, a metal fluoride, a metal nitride, a metal carbon oxynitride, silicon oxide, silicon nitride, or a combination thereof.
  • a metal element an alloy, a metal oxide, a metal fluoride, a metal nitride, a metal carbon oxynitride, silicon oxide, silicon nitride, or a combination thereof.
  • Any of the "metals” described herein are non-deliquescent metals, i.e., do not occur or substantially do not absorb moisture in the air, and do not occur or substantially do not undergo chemical changes in the presence of water.
  • the metal fluoride is selected from the group consisting of magnesium fluoride, calcium fluoride, barium fluoride, lead fluoride, or a combination thereof.
  • the surface treatment layer is coated on the surface of the substrate by a method selected from the group consisting of covering, wrapping, pasting, electroplating, evaporation, electroless plating, sputtering, spraying, dipping, vacuum evaporation. , sputtering, deposition, or a combination thereof.
  • the surface treatment layer is a single layer or a multilayer structure
  • the multilayer structure is a two-layer, three-layer, four-layer, five-layer structure; wherein each layer in the multilayer structure is the same material Or different materials.
  • the surface treatment layer has a thickness of 0.01 to 100 ⁇ m.
  • the surface treatment layer has a thickness of 0.05 to 50 ⁇ m.
  • the surface treatment layer has a thickness of 0.1 to 10 ⁇ m.
  • the retarding body is disposed in a cone shape in which two opposite directions are adjacent to each other.
  • the pyramid shape includes a first diameter, a second diameter, and a third diameter, the first diameter length being 1 cm-20 cm, and the second diameter length being 30 cm-100 cm, the first The three-diameter length is from 1 cm to 50 cm, and the material of the slow-moving body has a density of 80% to 100% of the theoretical density.
  • a second aspect of the present invention provides a beam shaping body comprising a retarding body and a beam inlet according to the first aspect of the present invention, a target, adjacent to the target, and surrounded by a reflector outside the retardation body, a thermal neutron absorber adjacent to the retarding body, and a radiation shield and a beam outlet disposed in the beam shaping body.
  • the beam shaping body further includes a third container, the inert gas layer being located between the second container and the substrate, and the third container for using the slowing speed
  • the substrate of the body is in an inert gas atmosphere as described in the first aspect.
  • the beam shaping body further includes a fourth container, the vacuum layer being located between the fourth container and the substrate, and the fourth container for using the retarding body
  • the substrate is in a vacuum atmosphere.
  • the beam shaping body further includes a fifth container for absorbing the slowing body and the beam inlet, the target, the reflector, and the thermal neutron of the shaping body
  • the body, radiation shield and beam exit are in an inert gas atmosphere as described in the first aspect.
  • the beam shaping body is used for accelerator boron neutron capture treatment
  • the accelerator boron neutron capture treatment accelerates the proton beam by an accelerator
  • the target is made of metal
  • the proton beam is accelerated to An energy sufficient to overcome the coulomb repulsion of the target nucleus, reacting nuclearly with the target to produce neutrons that slow the neutron to the epithermal neutron energy zone and reduce thermal neutrons and fast neutrons
  • the content, the epithermal energy region is between 0.5 eV and 40 keV
  • the thermal neutron energy region is less than 0.5 eV
  • the fast neutron energy region is greater than 40 keV
  • the reflector has strong neutron reflection capability.
  • the thermal neutron absorber is made of a material having a large cross section with thermal neutrons.
  • Figure 1 is a schematic diagram of a boron neutron capture reaction.
  • Figure 2 is a 10 B(n, ⁇ ) 7 Li neutron capture nuclear reaction equation.
  • FIG. 3 is a schematic plan view of a slowing body for moderating neutrons in an embodiment of the present invention, wherein the retarding body is disposed as a double cone.
  • FIG. 4 is a schematic view of a preparation apparatus of a slow-moving body material in an embodiment of the present invention, wherein the preparation apparatus is a discharge plasma sintering apparatus.
  • Fig. 5 is a schematic view showing a device for preparing a slow-moving body material in an embodiment of the present invention, wherein the preparing device is a hot press sintering device.
  • Fig. 6 is a schematic view showing a surface treatment layer of a retarding body in an embodiment of the present invention.
  • 1 is a beam shaping body
  • 2 is a beam entrance
  • 3 is a target
  • 4 is a retarding body adjacent to the target
  • 5 is a reflector surrounded by a slow-moving body
  • 6 is adjacent to the retarding body.
  • the thermal neutron absorber, 7 is the beam outlet
  • 401 is the surface treatment layer
  • 402 is the substrate.
  • a slow-acting body for slowing down neutrons which includes a slow-activating material, aluminum fluoride, which is easy to absorb moisture and deliquess, through the surface of the slow-acting body substrate. Coating the surface treatment layer can avoid the gradual moisture absorption and deliquescence of the slowing material during use, improve the quality of the neutron source and prolong the service life.
  • the present invention has been completed.
  • the surface treatment layer of the present invention comprises a hydrophobic organic polymer, a hydrophobic inorganic polymer, a metal element, an alloy, a metal oxide, a metal fluoride, a metal nitride, a metal carbon oxynitride, silicon oxide, silicon nitride, or combination.
  • the hydrophobic organic polymer is selected from the group consisting of: an organic fluoropolymer, a silicone polymer, a C2-20 substituted or unsubstituted olefinic polymer, a C2-20 substituted or unsubstituted acetylenic polymer, or combination.
  • the C2-20 substituted or unsubstituted olefinic polymer means a substituted or unsubstituted linear or branched olefin polymer having 2 to 20 carbon atoms
  • the "substituted" means The olefin polymer is substituted with one, two, three, four substituents selected from the group consisting of methyl, ethyl, propyl, fluorine, chlorine, bromine, sulfur, oxygen, phenyl, benzyl.
  • substituents selected from the group consisting of methyl, ethyl, propyl, fluorine, chlorine, bromine, sulfur, oxygen, phenyl, benzyl.
  • polytetrafluoroethylene, polystyrene, and polypropylene for example, polytetrafluoroethylene, polystyrene, and polypropylene.
  • the substituted or unsubstituted acetylenic polymer of C2-20 means a substituted or unsubstituted linear or branched alkyne polymer having 2 to 20 carbon atoms
  • the "substituted" means The alkyne polymer is substituted with one, two, three or four substituents selected from the group consisting of methyl, ethyl, propyl, fluorine, chlorine, bromine, sulfur, oxygen, phenyl, benzyl. .
  • substituents selected from the group consisting of methyl, ethyl, propyl, fluorine, chlorine, bromine, sulfur, oxygen, phenyl, benzyl.
  • the hydrophobic material is a hydrophobic material having a contact angle ⁇ of 110 to 180° with water, preferably having a contact angle ⁇ of 120-180°, and more preferably
  • the number of layers of the surface treatment layer is not particularly limited, and is preferably a single layer, two layers, three layers, four layers, or five layers; the layers may be the same material or different materials.
  • the thickness of the surface treatment layer is not particularly limited, and is preferably from 0.01 to 100 ⁇ m, more preferably from 0.1 to 10 ⁇ m.
  • the surface treatment layer may be a peelable surface treatment layer or a non-peelable surface treatment layer.
  • the coating method of the surface treatment layer is not particularly limited, and is preferably coated on the surface of the substrate by a method selected from the group consisting of covering, wrapping, pasting, plating, vapor deposition, electroless plating, sputtering, spraying, Impregnation, vacuum evaporation, sputtering, deposition, or any combination thereof.
  • the hydrophobic material is tightly covered on the surface of the substrate to isolate water in the environment, or the surface treatment layer is coated on the substrate by any of the film forming methods described.
  • the dry inert gas layer or vacuum layer coated on the surface of the substrate of the present invention means that the substrate is placed in a dry inert gas atmosphere or a vacuum atmosphere, and the inert gas layer or the vacuum layer is used to isolate the surface.
  • the substrate is in contact with water, especially water in the air.
  • the retarding body further comprises a first container, the inert gas layer being located between the first container and the substrate, the first container for placing the substrate in an inert gas atmosphere.
  • the inert gas comprises: nitrogen, helium, neon, argon, helium, neon, or a combination thereof.
  • the retarding body further comprises a second container, the vacuum layer being located between the second container and the substrate, the second container being for placing the substrate in a vacuum atmosphere.
  • Neutron capture therapy has been increasingly used as an effective means of treating cancer in recent years, with boron neutron capture therapy being the most common, and neutrons supplying boron neutron capture therapy can be supplied by nuclear reactors or accelerators.
  • Embodiments of the invention take the accelerator boron neutron capture treatment as an example.
  • the basic components of the accelerator boron neutron capture treatment typically include an accelerator, target and heat removal for accelerating charged particles (eg, protons, deuterons, etc.).
  • Systems and beam shaping bodies in which accelerated charged particles interact with metal targets to produce neutrons, depending on the desired neutron yield and energy, the energy and current of the accelerated charged particles, and the physicochemical properties of the metal target.
  • the nuclear reactions that are often discussed are 7 Li(p,n) 7 Be and 9 Be(p,n) 9 B, both of which are endothermic.
  • the energy thresholds of the two nuclear reactions are 1.881 MeV and 2.055 MeV, respectively. Since the ideal neutron source for boron neutron capture therapy is the superheated neutron of the keV energy level, theoretically, if proton bombardment with energy only slightly higher than the threshold is used.
  • a metallic lithium target that produces relatively low-energy neutrons that can be used clinically without too much slow processing.
  • proton interaction cross sections for lithium metal (Li) and base metal (Be) targets and threshold energy Not high, in order to generate a sufficiently large neutron flux, a higher energy proton is usually used to initiate the nuclear reaction.
  • embodiments of the present invention are directed to improvements proposed for slower bodies for neutron capture therapy, as a preferred embodiment for accelerator boron neutron capture therapy. Improvement of the slow speed body.
  • the beam shaping body 1 for the neutron capture treatment of the present invention the beam inlet 2, the target 3, the retarding body 4 adjacent to the target, and the reflector 5 surrounded by the retarding body, The thermal neutron absorber 6 adjacent to the retarding body, the beam outlet 7.
  • the target reacts nuclearly with the proton beam incident from the beam entrance to generate neutrons, the neutron forms a neutron beam, the neutron beam defines a major axis X, and the slowing body decelerates the neutrons generated from the target to super
  • the reflector will deviate from the neutron of the main axis X back to the main axis X to increase the intensity of the epithermal neutron beam, and a gap channel between the retarding body and the reflector to increase the superheat neutron flux
  • heat Neutron absorbers are used to absorb thermal neutrons to avoid excessive doses with shallow normal tissue during treatment
  • radiation shields are used to shield leaking neutrons and photons to reduce normal tissue dose in non-irradiated areas.
  • the accelerator boron neutron capture treatment accelerates the proton beam by an accelerator.
  • the target is made of lithium metal, and the proton beam is accelerated to an energy sufficient to overcome the coulomb repulsion of the target nucleus, and 7 Li is generated with the target.
  • the beam shaping body can slow the neutron to the super-heat neutron energy zone and reduce the thermal neutron and fast neutron content.
  • the slow-speed body is made of a material with a fast neutron action cross section and a super-thermal neutron action cross section.
  • the retarding body is made of a retarding material comprising aluminum fluoride and/or lithium fluoride which are hygroscopic and deliquescent.
  • the reflector is made of a material having a strong neutron reflection capability. As a preferred embodiment, the reflector is made of at least one of Pb or Ni.
  • the thermal neutron absorber is made of a material having a large cross section with thermal neutrons. As a preferred embodiment, the thermal neutron absorber is made of 6 Li, and air is provided between the thermal neutron absorber and the beam outlet. aisle.
  • the radiation shield includes a photon shield and a neutron shield. As a preferred embodiment, the radiation shield includes a photon shield made of lead (Pb) and a neutron shield made of polyethylene (PE).
  • FIG. 4 discloses a schematic of a spark plasma sintering apparatus.
  • the discharge plasma sintering apparatus 100 includes a first electrode 101, a second electrode 102, a conductive mold 103 interposed between the first electrode 101 and the second electrode 102, and a pulse current generator 104 that supplies a pulse current to the mold 103, with Pressurizing device 105 of pressurized pressurizing members 1051, 1052 and control device 106 for controlling pulse current generator 104 and pressurizing device 105, at least one of first electrode 101 and second electrode 102 can be moved, plus At least one of the pressing members 1051, 1052 is movable, and as a preferred example, the first electrode 101 and the pressing member 1051 are fixed, and the second electrode 102 and the pressing member 1052 are movable so as to be pressurizable into the mold 103.
  • the discharge plasma sintering apparatus 100 further includes a displacement measuring system 108 for measuring the displacement of the pressing device 105, an atmosphere control system 109 for controlling the atmosphere in the mold 103, and a water cooling system 111 for controlling the water-cooling vacuum chamber 110 to be cooled.
  • a temperature measuring device 112 for measuring the temperature within the discharge plasma sintering apparatus 100.
  • the mold 103 and the powder or powder compact 107 are subjected to a pulse current, in addition to providing discharge shock pressure and Joule heat for sintering, and further utilizing a spark discharge phenomenon (instantaneous generation of a high temperature plasma) generated between the powders at the initial stage of the pulse discharge.
  • the sintering promotion effect is rapid sintering by the instantaneous high temperature field, so that the powder or powder compact 107 is changed from a powder state to a block shape, and the so-called block shape is integrally formed without being required to be polished by a single crystal or by a single crystal.
  • the polishing and other processes are spliced into a size suitable for the slow speed body.
  • the spark plasma sintering apparatus 100 directly conducts sintering and pressurization using a direct current pulse current, and the temperature rising rate and the sintering temperature are controlled by the control unit 106 by adjusting the magnitude of the pulsed direct current.
  • the entire sintering process can be carried out under vacuum or in a protective atmosphere such as oxygen or hydrogen.
  • Sintering temperature is one of the key parameters in the rapid plasma sintering process.
  • the sintering temperature is determined by considering the phase transition of the sintered body sample at high temperature, the growth rate of the crystal grains, the quality requirements of the sample, and the density requirements of the sample. Under normal circumstances, as the sintering temperature increases, the density of the sample increases as a whole, which indicates that the sintering temperature has a significant effect on the density of the sample. The higher the sintering temperature, the faster the material transfer rate during sintering. The easier it is to be dense.
  • the higher the temperature the faster the growth rate of the grains and the worse the mechanical properties.
  • the temperature is too low, the density of the sample is very low, and the quality is not up to the requirement.
  • the contradiction between temperature and grain size requires a suitable parameter in the choice of temperature.
  • Prolonging the holding time at the sintering temperature generally promotes the sintering to a different extent and improves the microstructure of the sample. This is more obvious for the viscous flow mechanism, but less for the bulk diffusion and surface diffusion mechanism.
  • the density of the sample reaches 96.5% of the theoretical density.
  • the holding time increases, the density of the sample increases, but the variation range is not very large, indicating the holding time to the sample.
  • the density of the film has a certain influence, the effect is not very obvious.
  • the acceleration of the time heating rate makes the sample reach the required temperature in a short time, and the growth time of the crystal grains is greatly reduced, which is not only beneficial for suppressing the growth of the crystal grains, but also obtaining a fine-grained ceramic having a uniform size. Save time, save energy and increase the utilization of sintering equipment.
  • the rapid heating rate will have a devastating effect on the device. Therefore, the heating rate is accelerated as much as possible within the allowable range. However, it is reflected in the measured experimental data. Different from the sintering temperature and holding time, the effect of heating rate on the density of the sample shows the opposite result, that is, as the heating rate increases, the densification of the sample shows a tendency to gradually decrease.
  • the temperature rising process is generally divided into three stages, from room temperature to 600 ° C, 600 ° C to 900 ° C, 900 ° C to sintering temperature: the first stage is the preparation stage, the heating rate is relatively compared Slow; the second stage is a controllable rapid heating stage, the heating rate is generally controlled at 100-500 (°C/min); the third stage is the buffering stage of heating, the temperature is slowly raised to the sintering temperature, and the holding time is generally 1 ⁇ 7 minutes, after cooling, the furnace is cooled, the cooling rate can reach 300 ° C / min.
  • the powder is subjected to press forming and sintering immediately after being sufficiently discharged.
  • the sintered material undergoes severe plastic deformation under the joint action of the resistance Joule heat and pressure.
  • the application of the forming pressure is beneficial to enhance the contact between the powder particles, increase the sintering area, discharge the residual gas between the sintered powders, and improve the strength and density of the workpiece.
  • the size of the forming pressure is generally determined according to the compressibility of the sintered powder and the requirements for the properties such as the density and strength of the sintered material, and is generally in the range of 15 to 30 MPa, and sometimes as high as 50 MPa or even higher. Generally, the greater the forming pressure, the higher the density of the sintered material.
  • the duration of pressurization also has a large effect on the density of the sintered material.
  • the appropriate pressurization time varies depending on the type of the sintered material, the particle size and the geometrical size of the material to be sintered, and needs to be determined experimentally.
  • the duration of pressurization is equal to or slightly greater than the discharge time, which is a necessary condition for obtaining the highest density sintered material. It is easy to understand from the mechanism of sintering and solid phase reaction. The higher the pressure, the tighter the particle packing in the sample, and the mutual contact points and contact areas increase the sintering speed. This allows the sample to have a better density and effectively inhibits grain growth and lowers the sintering temperature. Therefore, the pressure selected is generally 30 to 50 MPa. However, some studies have shown that when the external pressure is 30Mpa and 50Mpa, the density of the sample is not much different, which indicates that the phenomenon of density increase with pressure is only obvious within a certain range.
  • Spark plasma sintering has the following advantages over conventional sintering techniques: fast sintering speed; improved material microstructure and improved material properties.
  • the mold can be made of other conductive materials, and the discharge plasma sintering apparatus can also be arranged such that both electrodes are stationary and only at least one of the pressure members can be moved.
  • the main process flow of spark plasma sintering is divided into four stages.
  • the first stage applying an initial pressure to the powder sample to make sufficient contact between the powder particles to subsequently produce a uniform and sufficient discharge plasma in the powder sample;
  • the second stage applying a pulse current, under the action of the pulse current, the powder The particle contact point generates a discharge plasma, and the surface of the particle generates a micro-discharge phenomenon due to activation;
  • the third stage the pulse power supply is turned off, and the sample is subjected to resistance heating until a predetermined sintering temperature is reached and the sample shrinks completely;
  • the fourth stage pressure relief.
  • Reasonable control of initial pressure, sintering time, forming pressure, pressurization duration, sintering temperature, heating rate and other major process parameters can obtain materials with good comprehensive performance.
  • the surface of the particle is maximally activated to accelerate the sintering densification process, which requires sintering.
  • the powder is applied with an appropriate initial pressure to bring the powder particles into full contact.
  • the initial pressure can vary depending on the type of sintered powder, the size of the sintered part, and the properties. When the initial pressure is too small, the discharge phenomenon is limited to a part of the powder, causing the powder to partially melt; if the pressure is too large, the discharge will be suppressed, thereby delaying the sintering diffusion process. According to the prior literature, in order to continue the discharge sufficiently, the initial pressure is generally not more than 10 MPa.
  • the sintering time is extremely short, even instantaneous, but the length of the sintering should be based on the powder quality, variety and performance. The difference is usually from a few seconds to a few minutes; even when sintering large, refractory metal powder materials, it can be as long as several tens of minutes.
  • the sintering time has a great influence on the density of the part. In order to make the densification process sufficiently, it is necessary to ensure a certain sintering time.
  • the spark plasma sintering process includes the steps of: filling the mold 103 with an appropriate amount of powder or powder compact 107; moving the pressurizing device 105 to pressurize the powder or powder compact 107 in the mold 103; through the control device 106
  • the pulse current generator 104 is turned on to conduct the mold 103 to generate plasma, the surface of the powder particles is activated and heated, and sintered into a block.
  • the spark plasma sintering process further includes the steps of: the control device 106 controls the displacement measuring system 108 to ensure that the displacement measuring system 108 is functioning properly, and the control device 106 controls the atmosphere control system 109 to ensure that the atmosphere within the mold 103 is in normal operation, the control device The water cooling system 111 is controlled 106 to ensure that it is in normal operation, and the control device 106 controls the temperature measuring device 112 to ensure that the temperature within the discharge plasma sintering apparatus 100 is in normal operation.
  • the so-called normal work refers to an alarm signal such as visual, tactile or auditory that does not occur to humans in the discharge plasma sintering apparatus, such as an alarm indicator light, an alarm indicator sound, an alarm indication vibration, and the like.
  • Hot-pressing sintering is a sintering method in which a dry powder is filled into a mold and heated while being pressed from a uniaxial direction to complete molding and sintering.
  • the production process of hot pressing sintering technology is very rich, and there is no uniform specification and standard in classification. According to the status quo, it can be divided into vacuum hot pressing, atmospheric hot pressing, shaking hot pressing, equalizing hot pressing, hot isostatic pressing, reactive hot pressing and ultra high pressure sintering.
  • the hot pressing sintering is carried out simultaneously by heating and pressing, and the powder is in a thermoplastic state, which contributes to the contact diffusion of the particles and the flow mass transfer process, so that the molding pressure is only 1/10 of the cold pressure; the sintering temperature can be lowered and shortened. Sintering time, thereby resisting grain growth, and obtaining a product having fine crystal grains, high density, and good mechanical and electrical properties.
  • the hot press sintering apparatus 200 mainly includes a heating furnace 201, a pressurizing device 202 placed in the heating furnace 201, a mold 203, and a powder or powder loaded into the mold 203.
  • the heating furnace 201 usually uses electricity as a heat source, and the heating element is made of SiC, MoSi or nickel filament, platinum wire, molybdenum wire or the like.
  • the pressurizing device 202 requires a gentle speed, a constant pressure, and a flexible pressure adjustment, and generally has a lever type and a hydraulic type.
  • the pressure atmosphere may be air or a reducing atmosphere or an inert atmosphere depending on the nature of the material.
  • the mold 203 is required to have high strength, high temperature resistance, oxidation resistance and no adhesion to the hot pressing material, and the thermal expansion coefficient of the mold 203 should be identical or similar to that of the hot pressing material.
  • a graphite mold is used in the embodiment.
  • the control device 205 causes the hot press sintering apparatus 200 to operate under normal conditions.
  • the so-called normal work refers to the visual, tactile or auditory alarm signals that the human plasma sensor does not have human discharge, such as the alarm indicator lights up, the alarm indicator lights, the alarm indicates vibration, and the like.
  • the production process generally includes the following steps: preparation of MgF 2 raw material - raw material grinding, screening treatment - transfer into the mold - high temperature sintering - high temperature Hot pressing sintering - cooling out of the furnace - hot isostatic pressing high temperature sintering - cooling out of the furnace - grinding, polishing, bonding - finished products.
  • the hot press sintering process includes the steps of: filling the mold 203 with an appropriate amount of powder or powder compact 204; turning on the hot press 201 to preset pressure and temperature parameters; moving the pressurizing device 202 to the powder or powder compact 204 in the mold 203 Pressurization; control device 205 controls hot press sintering apparatus 200 in the case of normal operation; energization to sinter into a block.
  • the step in the hot press sintering process “the moving pressurizing device 202 pressurizes the powder or the powder compact 204 in the mold 203” may be pre-pressurized or may be performed in synchronization with the energization, that is, the step "moving"
  • the pressurizing device 202 pressurizes the powder or powder compact 204 in the mold 203 and the step "energizes to sinter into a block".
  • the surface treatment layer 401 is coated on the surface of the retarding body substrate 402, wherein the surface treatment layer may be a single layer or a multi-layer structure, and the multilayer structure may be a second layer. , three-layer, four-layer, five-layer structure; wherein each layer in the multilayer structure may be the same material or different materials.
  • the thickness of the surface treatment layer is not particularly limited, and different thicknesses may be selected depending on the material of the surface treatment layer and different processes, and the thickness is preferably 0.01 to 100 ⁇ m, and more preferably 0.1 to 10 ⁇ m.
  • the surface treatment layer is coated on the surface of the substrate by a method selected from the group consisting of covering, wrapping, pasting, electroplating, vapor deposition, electroless plating, sputtering, spraying, dipping, vacuum evaporation, sputtering, Deposition, or any combination thereof.
  • the retarding body for slowing down neutrons disclosed in the present invention is not limited to the contents described in the above embodiments and the structures shown in the drawings. Obvious modifications, substitutions, or alterations of the materials, shapes and positions of the components in the present invention are within the scope of the invention as claimed.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Ceramic Engineering (AREA)
  • Materials Engineering (AREA)
  • Structural Engineering (AREA)
  • Organic Chemistry (AREA)
  • Health & Medical Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Biomedical Technology (AREA)
  • Manufacturing & Machinery (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Radiology & Medical Imaging (AREA)
  • General Health & Medical Sciences (AREA)
  • Veterinary Medicine (AREA)
  • Public Health (AREA)
  • Pathology (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Animal Behavior & Ethology (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • High Energy & Nuclear Physics (AREA)
  • General Engineering & Computer Science (AREA)
  • Inorganic Chemistry (AREA)
  • Plasma & Fusion (AREA)
  • General Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Physical Vapour Deposition (AREA)
  • Particle Accelerators (AREA)
  • Radiation-Therapy Devices (AREA)

Abstract

一种用于慢化中子的缓速体，包括基材(402)以及包覆于所述基材(402)表面的表面处理层(401)或干燥的惰性气体层或真空层；其中，所述基材(402)由慢化材料经粉末烧结设备通过粉末烧结工艺由粉末或粉末压坯变成块制备得到，所述慢化材料包括40-100％重量份的氟化铝，所述表面处理层(401)为疏水材料；所述表面处理层(401)或干燥的惰性气体层或真空层用于隔绝所述基材(402)和基材(402)所处环境中的水。经表面处理后的缓速体可以避免慢化材料在使用过程中的吸湿潮解，改善了中子射源的品质并延长了使用寿命。

Description

用于慢化中子的缓速体 技术领域
本发明涉及医疗设备领域，具体地，涉及到一种用于慢化中子的缓速体。
背景技术
硼中子捕获治疗(Boron Neutron Capture Therapy,BNCT)是利用含硼( 10B)药物对热中子具有高捕获截面的特性，借由 10B(n,α) 7Li中子捕获及核分裂反应产生 4He和 7Li两个重荷电粒子。参照图1和图2，其分别示出了硼中子捕获反应的示意图和 10B(n,α) 7Li中子捕获核反应方程式，两荷电粒子的平均能量约为2.33MeV，具有高线性转移(Linear Energy Transfer,LET)、短射程特征，α粒子的线性能量转移与射程分别为150keV/μm、8μm，而 7Li重荷粒子则为175keV/μm、5μm，两粒子的总射程约相当于一个细胞大小，因此对于生物体造成的辐射伤害能局限在细胞层级，当含硼药物选择性地聚集在肿瘤细胞中，搭配适当的中子射源，便能在不对正常组织造成太大伤害的前提下，达到局部杀死肿瘤细胞的目的。高能量中子射线照射正常细胞，会伤害DNA，引起皮肤炎症和放射性贫血、白血球减少等副作用。BNCT所需的超热中子能量较低，而一般中子源产生的中子平均能量较高，一次对病人照射之前需要对不同能区的中子进行适宜慢化过滤。目前常用的慢化材料有铝、氟化铝、氧化铝、氟化镁、氟化钙等，但是氟化铝、氟化钙等金属氟化物长时间暴露在空气中可能会导致吸水甚至潮解等物理化学改变，影响材料的使用性能，因此需要一种有效避免慢化材料吸水潮解的方法。
发明内容
本发明的目的是提供一种防潮解的用于慢化中子的缓速体。
在本发明第一方面提供了一种用于慢化中子的缓速体，所述缓速体包括基材以及包覆于所述基材表面的表面处理层或干燥的惰性气体层或真空层；其中，所述基材由慢化材料经粉末烧结设备通过粉末烧结工艺由粉末或粉末压坯变成块制备得到，所述慢化材料包括：40-100％重量份的氟化铝；其中，所述表面处理层为疏水材料；所述表面处理层或干燥的惰性气体层或真空层用于隔绝所述基材和基材所处环境中的水。
在另一优选例中，所述缓速体还包括第一容器，所述惰性气体层位于所述第一容器与所述基材之间，所述第一容器用于将所述基材处于惰性气体氛围中。
在另一优选例中，所述缓速体还包括第二容器，所述真空层位于所述第二容器与所述基 材之间，所述第二容器用于将所述基材处于真空氛围中。
在另一优选例中，所述惰性气体包括：氮气、氦气、氖气、氩气、氪气、氙气，或其组合。
在另一优选例中，所述慢化材料包括50-90％重量份的氟化铝以及任选的氟化锂、铝、氟化铅、氧化铝、氟化钙或氟化镁中的一种或多种混合材料。
在另一优选例中，所述慢化材料包括90-99.9％重量份的氟化铝以及任选的0.1-10％重量份的氟化锂。
在另一优选例中，所述慢化材料包括：氟化铝和氟化锂，以及任选的铝、氟化铅、氧化铝、氟化钙或氟化镁中的一种或多种混合材料。
在另一优选例中，所述粉末烧结设备为热压烧结设备或放电等离子烧结设备。
在另一优选例中，所述粉末烧结工艺为热压烧结工艺或放电等离子烧结工艺。
在另一优选例中，所述表面处理层是可剥离的表面处理层。
在另一优选例中，所述表面处理层选自下组：疏水有机聚合物、疏水无机聚合物，或其组合。
在另一优选例中，所述疏水有机聚合物选自下组：有机氟聚合物、有机硅聚合物、C2-20的取代或未取代的烯类聚合物、C2-20取代或未取代的炔类聚合物，或其组合。
在另一优选例中，所述疏水材料是与水的接触角θ为110-180°的疏水材料，优选的接触角θ为120-180°，更优选的接触角θ为130-180°。
在另一优选例中，所述表面处理层选自下组：金属单质、合金、金属氧化物、金属氟化物、金属氮化物、金属碳氧氮化物、氧化硅、氮化硅，或其组合；其中任一所述的“金属”为不易潮解金属，即在空气中不发生或基本不发生吸湿行为，在有水环境下不发生或基本不发生化学性质的改变。
在另一优选例中，所述金属氟化物选自下组：氟化镁、氟化钙、氟化钡、氟化铅，或其组合。
在另一优选例中，所述表面处理层是通过选自下组的方法包覆于基材表面：覆盖、包裹、粘贴、电镀、蒸镀、化学镀、喷镀、喷涂、浸渍、真空蒸发、溅射、沉积，或其组合。
在另一优选例中，所述表面处理层为单层或多层结构，所述多层结构为二层、三层、四层、五层结构；其中多层结构中的各层为相同材料或不同材料。
在另一优选例中，所述表面处理层的厚度为0.01-100微米。
在另一优选例中，所述表面处理层的厚度为0.05-50微米。
在另一优选例中，所述表面处理层的厚度为0.1-10微米。
在另一优选例中，所述缓速体设置成两个相反方向相互邻接的锥体状。
在另一优选例中，所述锥体状包括第一直径、第二直径和第三直径，所述第一直径长度为1cm-20cm，所述第二直径长度为30cm-100cm，所述第三直径长度为1cm-50cm，所述缓速体的材料的密度为理论密度的80％-100％。
本发明第二方面提供了一种射束整形体，所述射束整形体包括如本发明第一方面所述的缓速体和射束入口、靶材、邻接于所述靶材的、包围在所述缓速体外的反射体、与所述缓速体邻接的热中子吸收体、及设置在所述射束整形体内的辐射屏蔽和射束出口。
在另一优选例中，所述射束整形体还包括第三容器，所述惰性气体层位于所述第二容器与所述基材之间，所述第三容器用于将所述缓速体的基材处于如第一方面所述的惰性气体氛围中。
在另一优选例中，所述射束整形体还包括第四容器，所述真空层位于所述第四容器与所述基材之间，所述第四容器用于将所述缓速体的基材处于真空氛围中。
在另一优选例中，所述射束整形体还包括第五容器，所述第五容器用于将所述整形体的缓速体和射束入口、靶材、反射体、热中子吸收体、辐射屏蔽和射束出口处于如第一方面所述的惰性气体氛围中。
在另一优选例中，所述射束整形体用于加速器硼中子捕获治疗，加速器硼中子捕获治疗通过加速器将质子束加速，所述靶材由金属制成，所述质子束加速至足以克服靶材原子核库伦斥力的能量，与所述靶材发生核反应以产生中子，所述射束整形体能将中子缓速至超热中子能区，并降低热中子及快中子含量，所述超热中子能区在0.5eV到40keV之间，所述热中子能区小于0.5eV，所述快中子能区大于40keV，所述反射体由具有中子反射能力强的材料制成，所述热中子吸收体由与热中子作用截面大的材料制成。
附图说明
为了更清楚地说明本发明实施例的技术方案，下面将对本发明实施例中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本发明的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的附图。
图1是硼中子捕获反应示意图。
图2是 10B(n,α) 7Li中子捕获核反应方程式。
图3是本发明一个实施例中用于慢化中子的缓速体的平面示意图，其中，缓速体设置成双锥体。
图4是本发明一个实施例中的缓速体材料的制备装置示意图，其中，该制备装置为放电等离子烧结设备。
图5是本发明一个实施例中的缓速体材料的制备装置示意图，其中，该制备装置为热压烧结设备。
图6是本发明一个实施例中的缓速体表面处理层示意图。
其中，1为射束整形体，2为射束入口，3为靶材，4为邻接于靶材的缓速体，5为包围在缓速体外的反射体，6为与缓速体邻接的热中子吸收体，7为射束出口，401为表面处理层，402为基材。
具体实施方式
本发明人经过广泛而深入的研究，发明了一种用于慢化中子的缓速体，所述缓速体包括易吸湿潮解的慢化材料氟化铝，通过在缓速体基材表面包覆表面处理层，可以避免慢化材料在使用过程中逐渐的吸湿、潮解，改善了中子射源的品质并延长了使用寿命。在此基础上，完成了本发明。
本发明所述表面处理层包括疏水有机聚合物、疏水无机聚合物、金属单质、合金、金属氧化物、金属氟化物、金属氮化物、金属碳氧氮化物、氧化硅、氮化硅，或其组合。所述疏水有机聚合物选自下组：有机氟聚合物、有机硅聚合物、C2-20的取代或未取代的烯类聚合物、C2-20取代或未取代的炔类聚合物，或其组合。其中所述C2-20的取代或未取代的烯类聚合物是指含有2-20个碳原子的取代或未取代的直链或支链的烯烃聚合物，所述“取代”是指所述烯烃聚合物被选自下组的一个、两个、三个、四个取代基取代：甲基、乙基、丙基、氟、氯、溴、硫、氧、苯基、苯甲基。例如聚四氟乙烯、聚苯乙烯、聚丙烯。其中所述C2-20的取代或未取代的炔类聚合物是指含有2-20个碳原子的取代或未取代的直链或支链的炔烃聚合物，所述“取代”是指所述炔烃聚合物被选自下组的一个、两个、三个、四个取代基取代：甲基、乙基、丙基、氟、氯、溴、硫、氧、苯基、苯甲基。例如聚四氟乙炔、聚苯乙炔、聚丙炔。所述疏水材料是与水的接触角θ为110-180°的疏水材料，优选的接触角θ为120-180°，更优选的接触角θ为130-180°。
所述表面处理层的层数没有特别的限制，优选地为单层、二层、三层、四层、五层结构；各层可以是相同材料，也可以是不同材料。所述表面处理层的厚度没有特别的限制，优选地为0.01-100微米，更优选地为0.1-10微米。
所述表面处理层可以是可剥离的表面处理层，也可以是不可剥离的表面处理层。所述表面处理层的包覆方法没有特别的限制，优选地是通过选自下组的方法包覆于基材表面：覆盖、包裹、粘贴、电镀、蒸镀、化学镀、喷镀、喷涂、浸渍、真空蒸发、溅射、沉积，或其任意组合方法。例如，将所述疏水材料紧密覆盖于所述基材表面以此隔绝环境中的水，或通过所述的任一成膜方法在所述基材上包覆表面处理层。
本发明所述的包覆于所述基材表面的干燥的惰性气体层或真空层是指将所述基材处于干燥的惰性气体氛围或真空氛围中，通过惰性气体层或真空层隔绝所述基材与水接触，尤其是空气中的水。优选地所述缓速体还包括第一容器，所述惰性气体层位于所述第一容器与所述基材之间，所述第一容器用于将所述基材处于惰性气体氛围中。其中，所述惰性气体包括：氮气、氦气、氖气、氩气、氪气、氙气，或其组合。优选地，所述缓速体还包括第二容器，所述真空层位于所述第二容器与所述基材之间，所述第二容器用于将所述基材处于真空氛围中。
中子捕获治疗作为一种有效的治疗癌症的手段近年来的应用逐渐增加，其中以硼中子捕获治疗最为常见，供应硼中子捕获治疗的中子可以由核反应堆或加速器供应。本发明的实施例以加速器硼中子捕获治疗为例，加速器硼中子捕获治疗的基本组件通常包括用于对带电粒子(如质子、氘核等)进行加速的加速器、靶材与热移除系统和射束整形体，其中加速带电粒子与金属靶材作用产生中子，依据所需的中子产率与能量、可提供的加速带电粒子能量与电流大小、金属靶材的物化性等特性来挑选合适的核反应，常被讨论的核反应有 7Li(p,n) 7Be及 9Be(p,n) 9B，这两种反应皆为吸热反应。两种核反应的能量阀值分别为1.881MeV和2.055MeV，由于硼中子捕获治疗的理想中子源为keV能量等级的超热中子，理论上若使用能量仅稍高于阀值的质子轰击金属锂靶材，可产生相对低能的中子，不须太多的缓速处理便可用于临床，然而锂金属(Li)和铍金属(Be)两种靶材与阀值能量的质子作用截面不高，为产生足够大的中子通量，通常选用较高能量的质子来引发核反应。
以下结合具体实施例，进一步说明本发明。需理解，以下的描述仅为本发明的最优选实施方式，而不应当被认为是对于本发明保护范围的限制。在充分理解本发明的基础上，下列实施例中未注明具体条件的实验方法，通常按照常规条件，或按照制造厂商所建议的条件，本领域技术人员可以对本发明的技术方案作出非本质的改动，这样的改动应当被视为包括于本发明的保护范围之中的。除非另外说明，否则百分比和份数是重量百分比和重量份数。
为了改善中子射源的通量与品质，本发明的实施例是针对用于中子捕获治疗的缓速体提出的改进，作为一种优选地，是针对用于加速器硼中子捕获治疗的缓速体的改进。如图3所 示，本发明用于中子捕获治疗的射束整形体1，射束入口2，靶材3，邻接于靶材的缓速体4，包围在缓速体外的反射体5，与缓速体邻接的热中子吸收体6，射束出口7。靶材与自射束入口入射的质子束发生核反应以产生中子，中子形成中子射束，中子射束限定一根主轴X，缓速体将自靶材产生的中子减速至超热中子能区，反射体将偏离主轴X的中子导回主轴X以提高超热中子射束强度，缓速体和反射体之间设置间隙通道以提高超热中子通量，热中子吸收体用于吸收热中子以避免治疗时与浅层正常组织造成过多剂量，辐射屏蔽用于屏蔽渗漏的中子和光子以减少非照射区的正常组织剂量。
加速器硼中子捕获治疗通过加速器将质子束加速，作为一种优选实施例，靶材由锂金属制成，质子束加速至足以克服靶材原子核库伦斥力的能量，与靶材发生 7Li(p,n) 7Be核反应以产生中子。射束整形体能将中子缓速至超热中子能区，并降低热中子及快中子含量，缓速体由具有快中子作用截面大、超热中子作用截面小的材料制成，作为一种优选实施例，缓速体有缓速材料制成，所述缓速材料包括易吸湿潮解的氟化铝和/或氟化锂。反射体由具有中子反射能力强的材料制成，作为一种优选实施例，反射体由Pb或Ni中的至少一种制成。热中子吸收体由与热中子作用截面大的材料制成，作为一种优选实施例，热中子吸收体由 6Li制成，热中子吸收体和射束出口之间设有空气通道。辐射屏蔽包括光子屏蔽和中子屏蔽，作为一种优选实施例，辐射屏蔽包括由铅(Pb)制成的光子屏蔽和由聚乙烯(PE)制成的中子屏蔽。
图4揭示了一种放电等离子烧结设备的示意图。放电等离子烧结设备100包括第一电极101、第二电极102、置于第一电极101和第二电极102之间的导电模具103、给模具103提供脉冲电流的脉冲电流发生器104、带有用于加压的加压件1051、1052的加压装置105和用于控制脉冲电流发生器104和加压装置105的控制装置106，第一电极101和第二电极102中的至少一个能够移动，加压件1051、1052中的至少一个能够移动，作为一种优选地，第一电极101和加压件1051固定，第二电极102和加压件1052能够移动，从而能够加压置于模具103内的粉末或粉末压坯107。作为一种优选地，导电模具103设置为铅或石墨。放电等离子烧结设备100进一步包括用于测量加压装置105的位移的位移测量系统108，用于控制所述模具103内气氛的气氛控制系统109，用于控制水冷真空室110来冷却的水冷系统111，用于测量放电等离子烧结设备100内的温度的温度测量装置112。模具103和粉末或粉末压坯107通上脉冲电流，除了提供放电冲击压力和焦耳热进行烧结之外，进一步利用脉冲放电初期粉体间产生的火花放电现象(瞬间产生高温等离子体)所引起的烧结促进作用通过瞬时高温场实现快速烧结，从而使得粉末或粉末压坯107从粉末状态变成块状，所谓的块状为一体成型，而不需要如长晶的方式，由单晶通过打磨或抛光等工序拼接成适合缓速体尺寸大小。
该放电等离子烧结设备100利用直流脉冲电流直接通电烧结和加压，经控制装置106通 过调节脉冲直流电流的大小控制升温速率和烧结温度。整个烧结过程可在真空环境下进行，也可在保护气氛中进行，如氧气或氢气。
在氧气气氛下，由于氧被烧结物表面吸附或发生化学反应作用，使晶体表面形成正离子缺位型的非化学计量化合物，正离子空位增加，同时使闭口气孔中的氧可直接进入晶格，并和氧离子空位一样沿表面进行扩散，扩散和烧结加速。当烧结由正离子扩散控制时，氧化气氛或氧分压较高并有利于正离子空位形成，促进烧结；由负离子扩散控制时，还原气氛或较低的氧分压将导致氧离子空位产生并促进烧结。
在氢气气氛下烧结样品时，由于氢原子半径很小，易于扩散并有利于闭口气孔的消除，氧化铝等类型的材料于氢气气氛下烧结可得到接近于理论密度的烧结体样品。
烧结温度是等离子快速烧结过程中一个关键的参数之一。烧结温度的确定要考虑烧结体样品在高温下的相转变、晶粒的生长速率、样品的质量要求以及样品的密度要求。一般情况下，随着烧结温度的升高，试样致密度整体呈上升趋势，这说明烧结温度对样品致密度程度有明显的影响，烧结温度越高，烧结过程中物质传输速度越快，样品越容易密实。
但是，温度越高，晶粒的生长速率就越快，其力学性能就越差。而温度太低，样品的致密度就很低，质量达不到要求。温度与晶粒大小之间的矛盾在温度的选择上要求一个合适的参数。
延长烧结温度下的保温时间，一般都会不同程度地促进烧结完成，完善样品的显微结构，这对粘性流动机理的烧结较为明显，而对体积扩散和表面扩散机理的烧结影响较小。在烧结过程中，一般保温仅1分钟时，样品的密度就达到理论密度的96.5％以上，随着保温时间的延长，样品的致密度增大，但是变化范围不是很大，说明保温时间对样品的致密度虽然有一定的影响，但是作用效果不是很明显。但不合理地延长烧结温度下的保温时间，晶粒在此时间内急剧长大，加剧二次重结晶作用，不利于样品的性能要求，而时间太短会引起样品的致密化下降，因此需要选择合适的保温时间。
时间升温速率的加快，使得样品在很短的时间内达到所要求的温度，晶粒的生长时间会大大减少，这不仅有利于抑制晶粒的长大，得到大小均匀的细晶粒陶瓷，还能节约时间、节约能源以及提高烧结设备的利用率。但是，由于设备本身的限制，升温速率过快对设备会造成破坏性影响。因此在可允许的范围内尽可能的的加快升温速率。但是，在实测的实验数据中反映到。与烧结温度和保温时间不同，升温速率对样品致密度的影响显示出相反的结果，即随着升温速率的增大，样品致密度表现粗化逐渐下降的趋势，有学者提出这是因为在烧结温度附近升温速率的提高相当于缩短了保温时间，因而样品致密度会有所下降。在实际的高 温烧结过程中，升温过程一般分为三个阶段，分别为从室温至600℃左右、600℃至900℃左右、900℃至烧结温度：第一阶段是准备阶段，升温速率相对比较缓慢；第二阶段是可控的快速升温阶段，升温速率一般控制在100～500(℃/min)；第三阶段是升温的缓冲阶段，该阶段温度缓慢升至烧结温度，保温时间一般是1～7分钟，保温后随炉冷却，冷却速率可达300℃/min。
粉末经充分放电处理后立即进行压制成形与烧结。烧结材料在电阻焦耳热和压力的共同作用下发生严重的塑性变形，施加成形压力有利于增强粉末颗粒间的接触、增加烧结面积、排出烧结粉末间的残余气体、提高制件强度、密度及其表面光洁度。成形压力的大小一般根据烧结粉末的压缩性和对烧结材料密度、强度等性能的要求决定，一般在15～30MPa范围内，有时可能高达50MPa，甚至更高。通常，成形压力越大，烧结材料的密度越高。加压持续时间对烧结材料密度也有很大的影响，合适的加压时间视烧结材料的种类、粉末粒度和所烧结材料的几何尺寸而不同，需要通过实验确定。实验证明，加压持续时间等于或稍大于放电时间，这是获取最高密度烧结材料的必要条件。从烧结和固相反应机理容易理解，压力越大，样品中颗粒堆积就越紧密，相互的接触点和接触面积增大烧结被加速。这样能使样品得到更好的致密度，并能有效的抑制晶粒长大和降低烧结温度。因此选择的压力一般为30～50Mpa。不过有研究表明，当烧结时外压力为30Mpa和50Mpa时，样品的致密度相差并不大，这说明致密度随压力增大的现象仅在一定范围内较为明显。
放电等离子烧结相比于常规烧结技术有以下优点：烧结速度快；改进材料显微结构和提高材料的性能。
本领域技术人员熟知的，模具可以使用其他的导电材料制成，放电等离子烧结设备也可以设置成两个电极均固定不动，而只有至少一个加压件能够移动。
放电等离子烧结的主要工艺流程共分四个阶段。第一阶段：向粉末样品施加初始压力，使粉末颗粒之间充分接触，以便随后能够在粉末样品内产生均匀且充分的放电等离子；第二阶段：施加脉冲电流，在脉冲电流的作用下，粉末颗粒接触点产生放电等离子，颗粒表面由于活化产生微放热现象；第三阶段：关闭脉冲电源，对样品进行电阻加热,直至达到预定的烧结温度并且样品收缩完全为止；第四阶段：卸压。合理控制初始压力、烧结时间、成形压力、加压持续时间、烧结温度、升温速率等主要工艺参数可获得综合性能良好的材料。
由于粉末颗粒之间的拱桥效应，它们一般不能充分接触，因此，为了使电火花烧结时在样品内产生均匀并且充分放电的等离子，最大程度地活化颗粒表面以加速烧结致密化过程，需要向烧结粉末施加适当的初始压力，使粉末颗粒充分接触。初始压力的大小可随烧结粉末品种、烧结件大小和性能而不同。初压过小，放电现象只局限于部分粉末中，导致粉末局部 熔化；压力过大，将会抑制放电，进而延缓烧结扩散过程。根据现有文献，为使放电持续而充分地进行，此初始压力一般不宜超过10MPa。
当用电火花烧结导电性能较好的粉末试样时，由于电阻加热从样品的外部和内部同时进行，因此烧结时间极短，甚至是瞬间的，但烧结时间长短应视粉末质量、品种和性能而不同，一般为几秒钟到几分钟；当烧结大型、难熔金属粉末材料时，甚至长达几十分钟。烧结时间对制件密度影响较大，为使致密化过程得以充分进行，需要确保一定的烧结时间。
一般认为，放电等离子烧结过程中快速升温对粉末的烧结是很有利的，因为它抑制了材料的非致密化机制而激活了材料的致密化机制，因此，提高升温速率，能使样品的致密化程度得到提高。
作为一种优选地，放电等离子烧结工艺包括如下步骤：用适量的粉末或粉末压坯107填充模具103；移动加压装置105对模具103内的粉末或粉末压坯107加压；通过控制装置106打开脉冲电流发生器104以将模具103导电从而产生等离子体，粉末颗粒表面被活化和发热；烧结成块。放电等离子烧结工艺进一步包括如下步骤：控制装置106控制位移测量系统108以确保位移测量系统108正常工作，控制装置106控制气氛控制系统109以确保模具103内的气氛在正常工作的情形下，控制装置106控制水冷系统111以确保其在正常工作的情形下，控制装置106控制温度测量装置112以确保放电等离子烧结设备100内的温度在正常工作的情形下。所谓的正常工作指的是放电等离子烧结设备未发生人类感知的视觉、触觉或听觉等报警信号，如报警指示灯亮起，报警指示灯响起，报警指示振动等等诸如此类。
热压烧结是将干燥粉料充填入模型内，再从单轴方向边加压边加热，使成型和烧结同时完成的一种烧结方法。热压烧结技术生产工艺十分丰富，分类目前无统一规范和标准。依据现状可以分为真空热压、气氛热压、震动热压、均衡热压、热等静压、反应热压和超高压烧结。热压烧结由于加热加压同时进行，粉料处于热塑性状态，有助于颗粒的接触扩散、流动传质过程的进行，因而成型压力仅为冷压的1/10；还能降低烧结温度，缩短烧结时间，从而抵制晶粒长大，得到晶粒细小、致密度高和机械、电学性能良好的产品。
为了采用热压烧结工艺制备缓速体材料参照图5，热压烧结设备200主要包括加热炉201、置于加热炉201内的加压装置202、模具203、装入模具203内的粉末或粉末压坯204和控制装置205。加热炉201通常以电作为热源，加热元件由SiC、MoSi或镍络丝、白金丝、钼丝等。加压装置202要求速度平缓、保压恒定、压力灵活调节，一般有杠杆式和液压式。根据材料性质的要求，压力气氛可以是空气也可以是还原气氛或惰性气氛。模具203要求高强度、耐高温、抗氧化且不与热压材料黏结，模具203热膨胀系数应与热压材料一致或近似，作为一种优选地，本实施例中采用石墨模具。控制装置205使得热压烧结设备200在正常工作的情形下。所谓的 正常工作指的是放电等离子烧结设备未发生人类感知的视觉、触觉或听觉等报警信号，如报警指示灯亮起，报警指示灯响起，报警指示振动等等诸如此类。
以氟化铝采用热压烧结工艺制备目标缓速体为例，其生产工艺流程大致包括如下步骤，MgF 2原料制备——原料研磨、筛分处理——转入模具——高温烧结——高温热压烧结——冷却出炉——热等静压高温烧结——冷却出炉——磨削、抛光加工、粘接——成品。
作为一种优选地，在此省略前序的粉末处理步骤和后序的烧结完成的处理步骤。热压烧结工艺包括如下步骤：用适量的粉末或粉末压坯204填充模具203；开启热压炉201以预设压力和温度参数；移动加压装置202对模具203内的粉末或粉末压坯204加压；控制装置205控制热压烧结设备200在正常工作的情形下；通电以烧结成块。
需要进一步说明的是，热压烧结工艺中的步骤“移动加压装置202对模具203内的粉末或粉末压坯204加压”可以作为预加压，也可以与通电同步进行，即将步骤“移动加压装置202对模具203内的粉末或粉末压坯204加压”和步骤“通电以烧结成块”合二为一。
缓速体表面处理层示意图参见图6，表面处理层401包覆于缓速体基材402表面，其中所述表面处理层可以为单层或多层结构，所述多层结构可以为二层、三层、四层、五层结构；其中多层结构中的各层可以为相同材料或不同材料。所述表面处理层的厚度没有特别的限制，根据表面处理层的材料和不同的工艺可以选择不同的厚度，优选的厚度为0.01-100微米，更优选的厚度为0.1-10微米。优选地，所述表面处理层是通过选自下组的方法包覆于基材表面：覆盖、包裹、粘贴、电镀、蒸镀、化学镀、喷镀、喷涂、浸渍、真空蒸发、溅射、沉积，或其任意组合方法。
本发明揭示的用于慢化中子的缓速体并不局限于以上实施例所述的内容以及附图所表示的结构。在本发明的基础上对其中构件的材料、形状及位置所做的显而易见地改变、替代或者修改，都在本发明要求保护的范围之内。

Claims (15)

  1. 一种用于慢化中子的缓速体，其特征在于，所述缓速体包括基材以及包覆于所述基材表面的表面处理层或干燥的惰性气体层或真空层；其中，所述基材由慢化材料经粉末烧结设备通过粉末烧结工艺由粉末或粉末压坯变成块制备得到，所述慢化材料包括：40-100％重量份的氟化铝；所述表面处理层为疏水材料。
  2. 如权利要求1所述的缓速体，其特征在于，所述慢化材料包括50-90％重量份的氟化铝以及任选的氟化锂、铝、氟化铅、氧化铝、氟化钙或氟化镁中的一种或多种混合材料。
  3. 如权利要求1所述的缓速体，其特征在于，所述缓速体还包括第一容器，所述惰性气体层位于所述第一容器与所述基材之间，所述第一容器用于将所述基材处于惰性气体氛围中。
  4. 如权利要求1所述的缓速体，其特征在于，所述缓速体还包括第二容器，所述真空层位于所述第二容器与所述基材之间，所述第二容器用于将所述基材处于真空氛围中。
  5. 如权利要求1所述的缓速体，其特征在于，所述表面处理层选自下组：疏水有机聚合物、疏水无机聚合物，或其组合。
  6. 如权利要求1或5所述的缓速体，其特征在于，所述表面处理层选自下组：金属单质、合金、金属氧化物、金属氟化物、金属氮化物、金属碳氧氮化物、氧化硅、氮化硅，或其组合。
  7. 如权利要求1所述的缓速体，其特征在于，所述表面处理层是通过选自下组的方法包覆于基材表面：覆盖、包裹、粘贴、电镀、蒸镀、化学镀、喷镀、喷涂、浸渍、真空蒸发、溅射、沉积，或其组合。
  8. 如权利要求1所述的缓速体，其特征在于，所述表面处理层为单层或多层结构，所述多层结构为二层、三层、四层、五层结构；其中多层结构中的各层为相同材料或不同材料。
  9. 如权利要求1所述的缓速体，其特征在于，所述表面处理层的厚度为0.01-100微米。
  10. 如权利要求1所述的缓速体，其特征在于，所述缓速体设置成两个相反方向相互邻接的锥体状。
  11. 如权利要求10所述的缓速体，其特征在于，所述锥体状包括第一直径、第二直径和第三直径，所述第一直径长度为1cm-20cm，所述第二直径长度为30cm-100cm，所述第三直径长度为1cm-50cm，所述缓速体的材料的密度为理论密度的80％-100％。
  12. 一种射束整形体，其特征在于，所述射束整形体包括：如权利要求1-11任一所述的缓速体和射束入口、靶材、邻接于所述靶材的、包围在所述缓速体外的反射体、与所述缓速体邻接的热中子吸收体、及设置在所述射束整形体内的辐射屏蔽和射束出口。
  13. 如权利要求12所述的射束整形体，其特征在于，所述射束整形体还包括：
    第三容器，所述惰性气体层位于所述第三容器与所述基材之间，所述第三容器用于将所述缓速体的基材处于惰性气体氛围中；和/或
    第四容器，所述真空层位于所述第四容器与所述基材之间，所述第四容器用于将所 述缓速体的基材处于真空氛围中。
  14. 如权利要求12所述的射束整形体，其特征在于，所述射束整形体还包括：第五容器，所述第五容器用于将所述整形体的缓速体和射束入口、靶材、反射体、热中子吸收体、辐射屏蔽和射束出口处于如第一方面所述的惰性气体氛围中。
  15. 如权利要求12-14任一所述的射束整形体，其特征在于，所述射束整形体用于加速器硼中子捕获治疗，加速器硼中子捕获治疗通过加速器将质子束加速，所述靶材由金属制成，所述质子束加速至足以克服靶材原子核库伦斥力的能量，与所述靶材发生核反应以产生中子，所述射束整形体能将中子缓速至超热中子能区，并降低热中子及快中子含量，所述超热中子能区在0.5eV到40keV之间，所述热中子能区小于0.5eV，所述快中子能区大于40keV，所述反射体由具有中子反射能力强的材料制成，所述热中子吸收体由与热中子作用截面大的材料制成。
PCT/CN2018/100384 2017-08-18 2018-08-14 用于慢化中子的缓速体 WO2019034043A1 (zh)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP18845737.8A EP3586921B1 (en) 2017-08-18 2018-08-14 Moderator for moderating neutrons
US16/561,234 US11400316B2 (en) 2017-08-18 2019-09-05 Moderator for moderating neutrons

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201710710213.7A CN109411108B (zh) 2017-08-18 2017-08-18 用于慢化中子的缓速体
CN201710710213.7 2017-08-18

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US16/561,234 Continuation US11400316B2 (en) 2017-08-18 2019-09-05 Moderator for moderating neutrons

Publications (1)

Publication Number Publication Date
WO2019034043A1 true WO2019034043A1 (zh) 2019-02-21

Family

ID=65362177

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2018/100384 WO2019034043A1 (zh) 2017-08-18 2018-08-14 用于慢化中子的缓速体

Country Status (4)

Country Link
US (1) US11400316B2 (zh)
EP (1) EP3586921B1 (zh)
CN (2) CN111494812B (zh)
WO (1) WO2019034043A1 (zh)

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018223487A1 (zh) * 2017-06-05 2018-12-13 南京中硼联康医疗科技有限公司 用于中子捕获治疗的射束整形体
RU2743972C1 (ru) * 2017-08-24 2021-03-01 Нойборон Медтех Лтд. Система нейтрон-захватной терапии
US11517769B2 (en) * 2019-07-10 2022-12-06 Ricoh Company, Ltd. Neutron beam transmission adjusting device comprising a neutron beam transmission unit including a neutron reactant, method for producing neutron beam transmission adjusting device, and neutron beam adjusting method
CN110965004B (zh) * 2019-09-04 2022-05-24 扬州斯帕克实业有限公司 一种耐高温腐蚀Mg-Pb-Al-B核屏蔽材料的制备方法
CN111072387A (zh) * 2019-12-31 2020-04-28 中国建筑材料科学研究总院有限公司 氟化铝复合陶瓷及其制备方法
TWI790709B (zh) * 2021-04-16 2023-01-21 國立大學法人筑波大學 用於放射線屏蔽材料之燒結體、放射線屏蔽材料及其製造方法
CN113186440A (zh) * 2021-04-28 2021-07-30 禾材高科(苏州)有限公司 一种氟化铝基陶瓷中子慢化材料及其制备方法
CN113808772A (zh) * 2021-09-10 2021-12-17 中山大学 一种中子慢化材料
CA3235629A1 (en) * 2021-10-27 2023-05-04 Tae Life Sciences, Llc Systems, devices, and methods for converting a neutron beam
CN114315356B (zh) * 2022-01-21 2023-05-26 东北大学 一种铝电解炭阳极抗氧化涂层及其制备方法
CN116375473A (zh) * 2023-03-30 2023-07-04 山东亚赛陶瓷科技有限公司 氟化镁基复合中子慢化材料及其制备方法

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006047115A (ja) * 2004-08-04 2006-02-16 Mitsubishi Heavy Ind Ltd 中性子発生装置及びターゲット、並びに中性子照射システム
CN102214488A (zh) * 2011-05-31 2011-10-12 航天材料及工艺研究所 一种含碳化硼石墨吸收球及制备工艺
CN104332190A (zh) * 2014-11-19 2015-02-04 中国核动力研究设计院 矿物绝缘组件及制备方法和具备矿物绝缘组件的安全装置
CN104511096A (zh) * 2014-12-08 2015-04-15 南京中硼联康医疗科技有限公司 用于中子捕获治疗的射束整形体
WO2015111586A1 (ja) * 2014-01-22 2015-07-30 日本軽金属株式会社 フッ化マグネシウム焼結体の製造方法、中性子モデレータの製造方法及び中性子モデレータ
CN205004353U (zh) * 2015-09-10 2016-01-27 惠州雷通光电器件有限公司 Led封装结构及led灯具
CN106938124A (zh) * 2016-01-04 2017-07-11 南京中硼联康医疗科技有限公司 中子缓速材料

Family Cites Families (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3166614A (en) * 1959-11-30 1965-01-19 Carborundum Co Process of making nuclear fuel element
JP2004317566A (ja) * 2003-04-11 2004-11-11 Orc Mfg Co Ltd レーザ装置及びレーザ波長変換装置
US20090130447A1 (en) * 2007-11-16 2009-05-21 Nth Tech Corporation Hydrophilic systems and methods thereof
CN101471157A (zh) * 2007-12-24 2009-07-01 北京有色金属研究总院 金属浸渍与电镀结合保护单畴YBaCuO超导块材及其制备方法
CN101265099B (zh) * 2008-04-11 2012-03-14 中国科学技术大学 一种高温超导材料的制备方法
US20120330084A1 (en) * 2011-06-27 2012-12-27 Richard Harris Pantell Neutron Source for Neutron Capture Therapy
US20130095307A1 (en) * 2011-10-17 2013-04-18 Cella Energy Limited Spacecraft and spacesuit shield
EP2822911B1 (fr) * 2012-03-09 2019-11-20 Parexgroup Sa Composition seche a base de liant mineral et destinee a la preparation d'une formulation humide durcissable pour le batiment
EP2893537A2 (en) * 2012-09-05 2015-07-15 Transatomic Power Corporation Nuclear reactors and related methods and apparatus
JP6125827B2 (ja) * 2012-12-20 2017-05-10 トーカロ株式会社 放射線遮蔽コーティング部材及び放射線遮蔽コーティング部材の製造方法
US20160045841A1 (en) * 2013-03-15 2016-02-18 Transtar Group, Ltd. New and improved system for processing various chemicals and materials
CN107082642B (zh) * 2013-07-08 2021-11-16 国立大学法人筑波大学 中子射线减速材料用氟化物烧结体及中子射线减速材料
US9754687B2 (en) * 2013-09-03 2017-09-05 Uchicago Argonne, Llc ALD coating of nuclear fuel actinides materials
CN104975316A (zh) * 2014-04-02 2015-10-14 中国科学院海洋研究所 一种利用超疏水表面防止大气环境中因物质潮解所致腐蚀的方法
JP6473602B2 (ja) * 2014-11-12 2019-02-20 イビデン株式会社 黒鉛ブロック
PL3032926T3 (pl) * 2014-12-08 2017-07-31 Neuboron Medtech Ltd. Zespół kształtowania wiązki do terapii wychwytu neutronów
CN106310540A (zh) * 2015-05-04 2017-01-11 南京中硼联康医疗科技有限公司 用于中子捕获治疗的射束整形体
EP3254729B1 (en) * 2015-05-04 2019-09-04 Neuboron Medtech Ltd. Beam shaping body for neutron capture therapy
WO2017014230A1 (ja) * 2015-07-21 2017-01-26 日本軽金属株式会社 フッ化マグネシウム焼結体、フッ化マグネシウム焼結体の製造方法、中性子モデレータ及び中性子モデレータの製造方法
CN205235192U (zh) * 2015-11-12 2016-05-18 南京中硼联康医疗科技有限公司 中子捕获治疗系统
WO2017118291A1 (zh) * 2016-01-08 2017-07-13 南京中硼联康医疗科技有限公司 用于中子捕获治疗的射束整形体

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006047115A (ja) * 2004-08-04 2006-02-16 Mitsubishi Heavy Ind Ltd 中性子発生装置及びターゲット、並びに中性子照射システム
CN102214488A (zh) * 2011-05-31 2011-10-12 航天材料及工艺研究所 一种含碳化硼石墨吸收球及制备工艺
WO2015111586A1 (ja) * 2014-01-22 2015-07-30 日本軽金属株式会社 フッ化マグネシウム焼結体の製造方法、中性子モデレータの製造方法及び中性子モデレータ
CN104332190A (zh) * 2014-11-19 2015-02-04 中国核动力研究设计院 矿物绝缘组件及制备方法和具备矿物绝缘组件的安全装置
CN104511096A (zh) * 2014-12-08 2015-04-15 南京中硼联康医疗科技有限公司 用于中子捕获治疗的射束整形体
CN205004353U (zh) * 2015-09-10 2016-01-27 惠州雷通光电器件有限公司 Led封装结构及led灯具
CN106938124A (zh) * 2016-01-04 2017-07-11 南京中硼联康医疗科技有限公司 中子缓速材料

Also Published As

Publication number Publication date
CN109411108A (zh) 2019-03-01
CN111494812A (zh) 2020-08-07
EP3586921A4 (en) 2020-03-25
US11400316B2 (en) 2022-08-02
CN109411108B (zh) 2020-06-12
EP3586921A1 (en) 2020-01-01
CN111494812B (zh) 2022-03-22
US20210060360A1 (en) 2021-03-04
EP3586921B1 (en) 2021-04-14

Similar Documents

Publication Publication Date Title
WO2019034043A1 (zh) 用于慢化中子的缓速体
CN109568812B (zh) 用于中子捕获治疗的射束整形体
WO2016177270A1 (zh) 用于中子捕获治疗的射束整形体
US9868673B2 (en) Method for manufacturing magnesium fluoride sintered compact, method for manufacturing neutron moderator, and neutron moderator
TWI691238B (zh) 中子減速材料之製作方法
Klimov et al. Electron beam sintering of ceramics for additive manufacturing
CN106310540A (zh) 用于中子捕获治疗的射束整形体
CN115572961B (zh) 一种微波辅助气压浸渗制备金刚石复合材料的方法
CN116396089B (zh) 一种三维碳化硅/碳化钼陶瓷骨架增强碳基复合材料及其制备方法和应用
KR102114825B1 (ko) 방사선 차폐용 복합재료 제조방법
Cutroneo et al. Characterization of thin films for TNSA laser irradiation
CZ289688B6 (cs) Způsob výroby produktů na bázi ITO-slitin
WO2018226205A1 (en) Method and system for surface modification of substrate for ion beam target
CN107921273B (zh) 用于中子捕获治疗的射束整形体
CN102936714B (zh) 基于大面积强流脉冲电子束复合处理制备硬质碳化物陶瓷涂层的装置及其制备方法
CN110251847A (zh) 用于中子捕获治疗的射束整形体
RU2385517C1 (ru) СПОСОБ ИЗГОТОВЛЕНИЯ МИШЕНИ ДЛЯ МАГНЕТРОННОГО НАНЕСЕНИЯ СВЕРХПРОВОДНИКОВЫХ ПЛЕНОК СОСТАВА Bi-Pb-Sr-Ca-Cu-O
Yoon Electrical Leads for Gas Pressure System to 10 kbar at High Temperature

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: 18845737

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2018845737

Country of ref document: EP

Effective date: 20190923

NENP Non-entry into the national phase

Ref country code: DE