WO2024024771A1 - Ｘ線蛍光板、ｘ線検出器およびそれを用いたｘ線検査装置 - Google Patents

Ｘ線蛍光板、ｘ線検出器およびそれを用いたｘ線検査装置 Download PDF

Info

Publication number
WO2024024771A1
WO2024024771A1 PCT/JP2023/027148 JP2023027148W WO2024024771A1 WO 2024024771 A1 WO2024024771 A1 WO 2024024771A1 JP 2023027148 W JP2023027148 W JP 2023027148W WO 2024024771 A1 WO2024024771 A1 WO 2024024771A1
Authority
WO
WIPO (PCT)
Prior art keywords
ray
phosphor
layer
rays
fluorescent screen
Prior art date
Legal status (The legal status 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 status listed.)
Ceased
Application number
PCT/JP2023/027148
Other languages
English (en)
French (fr)
Japanese (ja)
Inventor
英二 小柳津
誠 林
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toshiba Corp
Niterra Materials Co Ltd
Original Assignee
Toshiba Corp
Toshiba Materials Co Ltd
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 Toshiba Corp, Toshiba Materials Co Ltd filed Critical Toshiba Corp
Priority to JP2024537736A priority Critical patent/JPWO2024024771A1/ja
Priority to EP23846501.7A priority patent/EP4563673A1/en
Priority to CN202380056569.7A priority patent/CN119631145A/zh
Publication of WO2024024771A1 publication Critical patent/WO2024024771A1/ja
Priority to US19/034,831 priority patent/US20250164651A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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
    • G01T1/2018—Scintillation-photodiode combinations
    • 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
    • G01T1/2023—Selection of materials
    • 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 materials, e.g. electroluminescent or chemiluminescent
    • C09K11/08—Luminescent materials, e.g. electroluminescent or chemiluminescent containing inorganic luminescent materials
    • C09K11/77—Luminescent materials, e.g. electroluminescent or chemiluminescent containing inorganic luminescent materials containing rare earth metals
    • C09K11/7728—Luminescent materials, e.g. electroluminescent or chemiluminescent containing inorganic luminescent materials containing rare earth metals containing europium
    • C09K11/7732—Halogenides
    • C09K11/7733—Halogenides with alkali or alkaline earth metals
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
    • G01N23/02—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material
    • G01N23/06—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material and measuring the absorption
    • G01N23/083—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material and measuring the absorption the radiation being X-rays
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
    • G01N23/02—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material
    • G01N23/06—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material and measuring the absorption
    • G01N23/10—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material and measuring the absorption the material being confined in a container, e.g. in a luggage X-ray scanners
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
    • G01N23/20—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by using diffraction of the radiation by the materials, e.g. for investigating crystal structure; by using scattering of the radiation by the materials, e.g. for investigating non-crystalline materials; by using reflection of the radiation by the materials
    • G01N23/20066—Measuring inelastic scatter of gamma rays, e.g. Compton effect
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2223/00—Investigating materials by wave or particle radiation
    • G01N2223/50—Detectors
    • G01N2223/505—Detectors scintillation
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2223/00—Investigating materials by wave or particle radiation
    • G01N2223/60—Specific applications or type of materials
    • G01N2223/643—Specific applications or type of materials object on conveyor
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
    • G01N23/02—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material
    • G01N23/04—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material and forming images of the material

Definitions

  • Embodiments of the present invention relate to an X-ray fluorescent screen, an X-ray detector, and an X-ray inspection device using the same.
  • Transmission X-ray inspection devices that utilize the transmission of X-rays and Compton scattering X-ray inspection devices that utilize Compton scattering of X-rays are widely used in airports and the like as counter-terrorism measures.
  • Such X-ray inspection equipment generally guides X-rays or Compton scattered X-rays that have passed through the inspected object to an X-ray detector, converts the detected X-rays into visible light using a phosphor, and then converts the detected X-rays into visible light.
  • the inspection is performed by detecting the intensity with a photomultiplier, and creating an image of the inside of the baggage according to the intensity.
  • the problem to be solved by the present invention is to provide a fluorescent screen that maintains afterglow characteristics and has high light output.
  • the fluorescent screen is configured to convert X-rays into visible light, and includes a first layer, a second layer, and a space between the first layer and the second layer.
  • a third layer containing a phosphor provided in the phosphor the phosphor is made of europium-activated barium fluoride chloride, and the weight of the phosphor is 300 mg/cm 2 or more and 600 mg/cm 2 or less,
  • a phosphor screen is provided, in which the first layer and the second layer each have a total light transmittance of 70% or more with respect to the emission wavelength of 380 nm of the phosphor.
  • FIG. 1 is a perspective view schematically showing an X-ray inspection apparatus according to the present embodiment.
  • FIG. 1 is a schematic cross-sectional view showing the configuration of a scattered X-ray detector according to the present embodiment.
  • FIG. 1 is a schematic diagram showing the configuration of a transmission X-ray detector according to the present embodiment.
  • FIG. 1 is a schematic cross-sectional view showing a fluorescent screen according to the present embodiment.
  • FIG. 3 is a diagram showing the relationship between the concentration of europium in the phosphor and the relative light output of the phosphor screen according to the present embodiment.
  • FIG. 3 is a diagram showing the relationship between the europium concentration of the phosphor and the afterglow characteristics of the phosphor screen according to the present embodiment.
  • FIG. 3 is a diagram showing the relationship between the phosphor weight and relative light output of the phosphor layer according to the present embodiment.
  • FIG. 3 is a diagram showing the relationship between the phosphor weight and relative light output of the phosphor layer according
  • FIG. 1 is a perspective view schematically showing an X-ray inspection apparatus according to the present embodiment.
  • the X-ray inspection apparatus includes an X-ray tube 1 as an X-ray irradiation section.
  • the X-ray tube 1 emits X-rays at an X-ray tube voltage in the range of 140 kV to 180 kV.
  • a more preferred X-ray tube voltage is 160 kV.
  • an X-ray tube voltage of 120 kV was used, but by using the fluorescent screen of this embodiment, which will be described later, it is possible to obtain clearer images by using a higher value than the conventional X-ray tube voltage. It is possible.
  • the emitted X-rays A are collimated by a slit having a predetermined width in the linear collimator 2.
  • the collimated X-rays B are shaped into a pencil beam that repeats linear motion by a rotating collimator 3 provided with a plurality of slits in the radial direction.
  • the pencil beam-shaped X-rays C are irradiated while scanning an object to be inspected, such as a baggage 5, which is moving on a conveyor 4, for example.
  • the cargo 5 moves at a speed depending on the X-ray detection sensitivity.
  • the X-rays reflected by the baggage 5, that is, the Compton scattered X-rays D, are detected by the scattered X-ray detector 6. Furthermore, the X-rays E that have passed through the baggage 5 are detected by the transmission X-ray detector 7. Compton scattered X-rays D detected by the scattered X-ray detector 6 and transmitted X-rays E detected by the transmitted X-ray detector 7 are measured as continuous intensity values. In accordance with this X-ray intensity, the state inside the luggage 5 is displayed as an image on a display unit (not shown) such as a liquid crystal display. The interior of the luggage 5 is inspected based on the displayed image.
  • FIG. 2 is a schematic cross-sectional view showing the configuration of the scattered X-ray detector 6 according to this embodiment. As shown in FIG. 2, two scattered X-ray detectors 6 are arranged with a gap therebetween for passage of pencil beam-shaped X-rays C.
  • the arrangement and number of scattered X-ray detectors 6 are not limited to these, and may be sufficient as long as they can allow X-rays C to pass therethrough and allow scattered X-rays from baggage 5 to enter.
  • the scattered X-ray detector 6 has a detector main body 8 shaped like a housing.
  • the detector main body 8 has an X-ray entrance part 8a on a surface facing the baggage 5, into which the Compton scattered X-rays D are incident.
  • the X-ray entrance portion 8a is made of a material that transmits X-rays, such as resin.
  • the other portion 8b of the detector main body 8 excluding the X-ray entrance part 8a is made of, for example, aluminum in order to maintain the strength of the detector main body 8.
  • the other portion 8b has one surface that is inclined with respect to the surface of the X-ray entrance portion 8a.
  • the one surfaces of the two scattered X-ray detectors 6 are provided to face each other, and these surfaces form a gap through which the X-rays C pass.
  • the outer surface of the other portion 8b of the detector main body 8 is covered with an X-ray shielding member 9 made of lead or the like. This is to eliminate the influence of external X-rays.
  • a transmissive fluorescent screen 10 is provided inside the X-ray entrance section 8a, with the light emitting direction directed toward the inside of the detector main body 8. Furthermore, a reflective fluorescent screen 11 is provided inside the other portion 8b of the detector main body 8.
  • a photomultiplier 12 is provided as a photoelectric conversion section on the other surface that is perpendicular to the surface of the X-ray entrance section 8a.
  • the photomultiplier 12 has a light receiving sensitivity peak around 400 nm, and for example, R-1307 (trade name) manufactured by Hamamatsu Photonics Co., Ltd. is used. Note that the configuration and shape of the detector main body 8, the type of photomultiplier 12, etc. are not limited to these.
  • the Compton scattered X-rays D1 that have entered the X-ray incidence section 8a of the detector main body 8 are irradiated onto a transmission type fluorescent screen 10.
  • the transmissive fluorescent screen 10 emits visible light a corresponding to the selected phosphor.
  • the visible light a is emitted toward the inside of the detector body 8.
  • the reflective fluorescent screen 11 emits visible light b corresponding to the selected phosphor.
  • the visible light b is emitted toward the inside of the detector body 8.
  • the visible lights a and b are detected by the photomultiplier 12, and the total intensity of the visible lights a and b is measured. In this way, the intensity of the Compton scattered X-rays incident on the scattered X-ray detector 6 is determined. By detecting Compton scattered X-rays, it is possible to identify objects that are mainly composed of elements with small atomic numbers, such as plastic products.
  • FIG. 3 is a schematic diagram showing the configuration of the transmission X-ray detector 7 according to this embodiment.
  • the transmission X-ray detector 7 is arranged so that the X-rays E that have passed through the object to be inspected enter a slit-shaped window 15 of the transmission X-ray detector 7 .
  • the transmission X-ray detector 7 has an elongated slit window 15 so that the X-rays E that have passed through the object to be inspected are efficiently incident into the transmission X-ray detector 7.
  • the window 15 is covered with a material 16 that absorbs little X-rays, such as a plastic film or a carbon plate.
  • the fluorescent screen 17 is provided on an installation plate 18 provided inside the transmitted X-ray detector 7.
  • the installation plate 18 is desirably transparent in order to efficiently extract the light emitted by the fluorescent screen 17 toward the installation plate 18 when irradiated with X-rays E.
  • the fluorescent screen 17 is provided at an angle with respect to the irradiation direction of the X-rays E to increase the irradiated area.
  • other parts of the transmission X-ray detector 7 except for the window 15 are made of, for example, aluminum in order to maintain strength.
  • the inner surface of the transmitted X-ray detector 7 is white in order to reflect light and focus it on the photomultiplier 19, and is made of, for example, white paint or white film.
  • a photomultiplier 19 is installed in the transmitted X-ray detector as a photoelectric conversion means.
  • the photomultiplier 19 has a light receiving sensitivity peak around 400 nm, and for example, R-1307 (trade name) manufactured by Hamamatsu Photonics Co., Ltd. is used. Note that the configuration and shape of the transmission X-ray detector 7, the type of photomultiplier 19, etc. are not limited to these.
  • the scattered X-ray detector 6 and the transmitted X-ray detector 7 are provided with fluorescent plates 10 and 17 that convert X-rays into visible light.
  • the fluorescent screens 10 and 17 will be explained below.
  • FIG. 4 is a schematic cross-sectional view showing the fluorescent screen 10 according to this embodiment.
  • the fluorescent screen 10 includes, for example, a support (first layer) 21, a protective layer (second layer) 22, and a phosphor layer (third layer) 23.
  • the phosphor layer 23 contains, for example, phosphor particles and a binder.
  • the binder is generally a resin binder, and various organic resins are used.
  • the phosphor layer 23 is formed by coating the support 21 with a slurry in which phosphor particles, a binder, and an organic solvent are mixed together.
  • the phosphor layer 23 includes phosphor particles made of europium-activated barium fluoride chloride phosphor BaFCl:Eu. A part of europium may be replaced with Ce, Yb, etc. Further, a part of fluorine and chlorine may be replaced with Br, I, or the like.
  • the scattered X-ray detector 6 typically uses a photomultiplier 12 having spectral sensitivity characteristics around 400 nm. Therefore, as a phosphor that converts X-rays into visible light, a phosphor having an emission wavelength peak around 400 nm is preferable in combination with the photomultiplier 12.
  • the emission spectrum of the europium-activated barium fluoride chloride phosphor has an emission wavelength peak near 380 nm and a broad waveform, so it is compatible with the photomultiplier 12.
  • the weight per unit area of the phosphor contained in the phosphor layer 23 is preferably 300 mg/cm 2 or more and 600 mg/cm 2 or less. If the weight of the phosphor is less than 300 mg/cm 2 , the element performance of the phosphor screen 10 will be inferior to the irradiated X-rays irradiated with an X-ray tube voltage of 160 kV, so the wavelength will be converted into visible light in the phosphor layer 23. A portion of the irradiated X-rays that were not present enters the photomultiplier 19 and generates noise. As a result, the S/N ratio of the X-ray detector deteriorates.
  • the optical output decreases. This is because the thickness of the phosphor layer 23 increases, making it difficult for X-rays to pass through, or the visible light generated by X-ray irradiation becomes difficult to reach the photomultiplier 19 due to self-absorption of the phosphor layer 23. This seems to be due to the following.
  • the fluorescent weight is in the range of 300 mg/cm 2 or more and 600 mg/cm 2 or less, the light output increases.
  • the fluorescent screen 10 with the fluorescent weight of this embodiment By using irradiation X with an X-ray tube voltage of 160 kV, a relative light output of 150% or more can be obtained. That is, it is possible to obtain a light output that is 1.5 times or more greater than that of a conventional fluorescent screen. This is because the fluorescent screen 10 of this embodiment can efficiently and effectively convert the wavelength of the irradiated X-rays, which have a higher intensity than the conventional ones, into visible light.
  • the boiling point of the solvent for the phosphor solution was By lowering the coating temperature to 100°C or lower, using 2/3 the amount of solvent, and lowering the line speed to 1/3 of the conventional coating conditions, sufficient drying was achieved even when the weight of the phosphor was 300 mg/cm2 or more .
  • a phosphor layer 23 can be formed on the support 21.
  • the average particle diameter of the particles of the europium-activated barium fluoride chloride phosphor in the phosphor layer 23 is preferably 3 ⁇ m or more and 6 ⁇ m or less. Since the phosphor layer 23 has transparency by increasing the average particle size of the phosphor particles, visible light converted from X-rays can be taken out to the outside of the phosphor screen 10 without being absorbed in the phosphor layer 23. can. Therefore, it is possible to increase the light output of the fluorescent screen 10. On the other hand, when the average particle size becomes large, a disadvantage arises in that the yield in phosphor production becomes poor. Considering the above, the average particle diameter is preferably 6 ⁇ m or less.
  • the average particle size is preferably 3 ⁇ m or more.
  • the concentration of europium in the europium-activated barium fluoride chloride phosphor is preferably 0.3% by weight or more and 1.5% by weight or less. In this concentration range, a relative light output of more than 140% can be obtained when irradiating X-rays with an X-ray tube voltage of 140 kV to 180 kV. Note that the relative light output is calculated by setting the light output when measuring at an X-ray tube voltage of 160 kV using a conventional fluorescent screen as 100%. Details will be described in Examples below.
  • the afterglow property of the phosphor used in an X-ray inspection device is such that the light output of the phosphor screen 10 after 20 ms has elapsed after irradiation with X-rays is 0.06% or less of that during irradiation. With this value, a clear image without afterimages can be obtained in the X-ray inspection apparatus.
  • the concentration of europium exhibiting a light output of 0.06% or less is 0.3% by weight or more, and has preferable afterglow characteristics within this range. From the above, in consideration of the relative light output of the phosphor screen 10 and the maintenance of the afterglow characteristics of the phosphor, the europium concentration range of the phosphor is preferably 0.3% by weight or more and 1.5% by weight or less.
  • the support 21 and the protective layer 22 of this embodiment have light transmittance.
  • the total light transmittance of the support 21 and the protective layer 22 is preferably 70% or more, and more preferably 85% or more in order to obtain a larger light output.
  • the total light transmittance is less than 70%, the light output of the fluorescent screen 10 decreases.
  • Conventional fluorescent screens are provided with a light-reflecting support, and the light emitted from the phosphor layer is guided to the protective layer provided on the opposite side of the support by utilizing the reflection of the support, and the photo The amount of light reaching the multiplier was increased.
  • a white film with a light reflectance of 70% or more was used as the support material.
  • the fluorescent screen 10 can obtain high light output.
  • a light-transmitting material such as a transparent plastic film can be used.
  • transparent polyethylene terephthalate it is preferable to use transparent polyethylene terephthalate.
  • the thickness of both the support 21 and the protective layer 22 is preferably 188 ⁇ m or more and 350 ⁇ m or less. If the thickness of the support 21 and the protective layer 22 is smaller than 188 ⁇ m, the strength of the fluorescent screen 10 cannot be maintained and it becomes easy to break. Further, the thickness of the support 21 and the protective layer 22 is preferably 350 ⁇ m from the viewpoint of strength, and making them unnecessarily thick may lead to an increase in the volume of the X-ray detector, so it is preferable. do not have.
  • the phosphor screen 10 is made by coating a slurry of a phosphor mixed with a binder and an organic solvent on a light-transmitting transparent polyethylene terephthalate support 13 using a knife coater or the like and drying it to form a phosphor layer 23.
  • a protective layer 22 made of light-transmitting transparent polyethylene terephthalate was laminated on the body layer 23 using a press or the like.
  • europium-activated barium fluoride chloride was used, the average particle size was 4 ⁇ m, and the concentration of europium was 0.75% by weight.
  • the phosphor weight of the phosphor layer 23 was 300 mg/cm 2 , and the total light transmittance of the support 21 and the protective layer 22 was 70%.
  • FIG. 5 shows the relationship between the concentration of europium in the europium-activated barium fluoride chloride phosphor of the phosphor layer 23 and the relative light output of the phosphor screen 10.
  • the relative light output was measured by irradiating the fluorescent screen 10 with X-rays at an X-ray tube voltage of 160 kV.
  • the average particle size of the europium-activated barium fluoride chloride phosphor was approximately 4 ⁇ m
  • the phosphor weight of the phosphor layer 23 was 250 mg/cm 2
  • the concentration of europium was 0.75% by weight
  • the support The value of the light output measured by irradiating X-rays with an X-ray tube voltage of 160 kV to the conventional fluorescent screen 10 having a light reflectance of 70% was defined as 100%.
  • the total light transmittance indicates the transmittance at 380 nm, which is the main emission wavelength of the europium-activated barium fluoride chloride phosphor.
  • Line 101 represents the measurement results. As shown in FIG.
  • FIG. 6 shows the relationship between the concentration of europium in the europium-activated barium fluoride chloride phosphor of the phosphor layer 23 and the afterglow characteristics of the phosphor screen 10.
  • the concentration of europium at which the optical output was 0.06% or less was 0.3% by weight or more.
  • FIG. 7 shows the relationship between the phosphor weight of the phosphor layer 23 and the relative light output of the phosphor screen 10 in comparison with a comparative example.
  • Table 1 shows part of the data plotted in FIG. 7, divided into Examples and Comparative Examples.
  • the average particle size of the europium-activated barium fluoride chloride phosphor was approximately 4 ⁇ m
  • the concentration of europium was 0.75% by weight
  • the weight of the phosphor was 250 mg/cm 2
  • the support A conventional fluorescent screen with a light reflectance of the body 21 of 70% was used, and X-rays were irradiated with an X-ray tube voltage of 120 kV.
  • the relative values of the optical outputs of the X-ray detectors of Examples and Comparative Examples were measured, with the measured value of the optical output of the X-ray detector in the measurement of the reference value being taken as 100%.
  • the average particle size of the europium-activated barium fluoride chloride phosphor was about 4 ⁇ m
  • the concentration of europium was 0.75% by weight
  • the total light transmittance of the support 21 and the protective layer 22 was 70%.
  • Line 103 represents the measurement results when the total light transmittance is 85%
  • line 104 represents the measurement results when the total light transmittance is 60%.
  • the support 21 and the protective layer 22 were made of transparent polyethylene terephthalate, and each had a thickness of 250 ⁇ m.
  • the total light transmittance of the support 21 and the protective layer 22 was set to 60%, and the measurement was performed using the same fluorescent screen as in the example, and the light reflectance of the support 21 was set to 70%.
  • the measurements were carried out using the same fluorescent screens as in the examples except for the above.
  • Line 105 represents the measurement results when the light reflectance is 70%
  • line 106 represents the measurement results when the total light transmittance is 60%.
  • the fluorescent screen with the support 21 and the protective layer 22 having a total light transmittance of 85% has a higher relative light output than the fluorescent screen with a total light transmittance of 70%. It showed a high value. Furthermore, the relative light output increased as the weight of the phosphor layer 23 increased. When the fluorescent weight was 300 mg/cm 2 or more, the relative light output was 150% or more. Moreover, the relative light output was maximum when the weight of the phosphor was 500 to 600 mg/cm 2 , and when it exceeded 600 mg/cm 2 , the relative light output decreased.
  • the total light transmittance of the support 21 and the protective layer 22 is 60%, and the fluorescent screen is otherwise the same as the example, and the light reflectance of the support 21 is 70%.
  • the relative light output shows a maximum value when the weight of the phosphor is approximately 300 mg/ cm2 , and when it exceeds 300 mg/ cm2 , the relative light output shows a constant value or decreases. did. Further, the maximum value of the relative light output was about 130%, which was lower than those of Examples 1 to 8.
  • the boiling point of the solvent of the phosphor solution was set to 100° C. or less, and the amount of solvent was reduced to 2/3 of the conventional amount.
  • the line speed was reduced to 1 ⁇ 3 under the coating conditions. As a result, a sufficiently dried phosphor layer 23 having a phosphor weight of 300 mg/cm 2 or more could be obtained.
  • FIG. 8 shows the relationship between the phosphor weight of the phosphor layer 23 and the relative light output of the phosphor screen 10 when the X-ray tube voltage is 120 kV and 160 kV.
  • the fluorescent screen 10 has a europium-activated barium fluoride chloride phosphor having an average particle size of about 4 ⁇ m, a europium concentration of 0.75% by weight, and a total of the support 21 and the protective layer 22.
  • the light transmittance was set to 70%. Further, measurements were performed using irradiated X-rays with an X-ray tube voltage of 120 kV or 160 kV.
  • the reference values for the relative light output are as follows: the average particle diameter of the europium-activated barium fluoride chloride phosphor is approximately 4 ⁇ m, the europium concentration is 0.75%, the phosphor weight is 250 mg/cm 2 , and the light reflectance of the support 21 is approximately 4 ⁇ m.
  • the measured value of the light output was taken as 100% when it was measured using a fluorescent screen with 70% and irradiated X-rays with an X-ray tube voltage of 120 kV.
  • Line 107 represents the measurement results when the X-ray tube voltage is 160 kV
  • line 108 represents the measurement results when the X-ray tube voltage is 120 kV.
  • the relative light output becomes maximum when the phosphor weight is 300 mg/cm 2 to 400 mg/cm 2 , and the value is about 130%, and when the phosphor weight is 400 mg/cm 2 , the relative light output is the maximum. When exceeded, the relative light output decreased. On the other hand, when the X-ray tube voltage was 160 kV, the relative light output was 150% or more in the fluorescent screen 10 whose fluorescent weight was in the range of 300 mg/cm 2 to 600 mg/cm 2 .
  • the phosphor layer 23 of the phosphor screen 10 contains europium-activated barium fluoride chloride, has a phosphor weight of 300 mg/cm 2 or more and 600 mg/cm 2 or less, and the support 21 and the protective layer 22 It is preferable that the total light transmittance is 70% or more with respect to the body's main emission wavelength of 380 nm.
  • the relative light output of the fluorescent screen 10 is 1.5 times that of a conventional fluorescent screen, which is the standard value, and the X-ray detector has good afterglow characteristics, a small S/N ratio, and a clear image can be obtained. An X-ray inspection device can be obtained.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Analytical Chemistry (AREA)
  • Pathology (AREA)
  • Immunology (AREA)
  • General Health & Medical Sciences (AREA)
  • Biochemistry (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Molecular Biology (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Toxicology (AREA)
  • Organic Chemistry (AREA)
  • Materials Engineering (AREA)
  • Engineering & Computer Science (AREA)
  • Inorganic Chemistry (AREA)
  • Luminescent Compositions (AREA)
  • Conversion Of X-Rays Into Visible Images (AREA)
PCT/JP2023/027148 2022-07-26 2023-07-25 Ｘ線蛍光板、ｘ線検出器およびそれを用いたｘ線検査装置 Ceased WO2024024771A1 (ja)

Priority Applications (4)

Application Number Priority Date Filing Date Title
JP2024537736A JPWO2024024771A1 (https=) 2022-07-26 2023-07-25
EP23846501.7A EP4563673A1 (en) 2022-07-26 2023-07-25 X-ray fluorescent plate, x-ray detector, and x-ray inspection device using same
CN202380056569.7A CN119631145A (zh) 2022-07-26 2023-07-25 X射线荧光板、x射线检测器以及使用其的x射线检查装置
US19/034,831 US20250164651A1 (en) 2022-07-26 2025-01-23 X-ray fluorescent screen, x-ray detector, and x-ray inspection device using same

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2022118349 2022-07-26
JP2022-118349 2022-07-26

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US19/034,831 Continuation US20250164651A1 (en) 2022-07-26 2025-01-23 X-ray fluorescent screen, x-ray detector, and x-ray inspection device using same

Publications (1)

Publication Number Publication Date
WO2024024771A1 true WO2024024771A1 (ja) 2024-02-01

Family

ID=89706404

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2023/027148 Ceased WO2024024771A1 (ja) 2022-07-26 2023-07-25 Ｘ線蛍光板、ｘ線検出器およびそれを用いたｘ線検査装置

Country Status (5)

Country Link
US (1) US20250164651A1 (https=)
EP (1) EP4563673A1 (https=)
JP (1) JPWO2024024771A1 (https=)
CN (1) CN119631145A (https=)
WO (1) WO2024024771A1 (https=)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62173100U (https=) 1986-04-21 1987-11-04
WO2013051165A1 (ja) * 2011-10-03 2013-04-11 株式会社 東芝 Ｘ線検出器用増感紙、ｘ線検出器、およびｘ線検査装置
JP2020517960A (ja) * 2017-04-28 2020-06-18 フラマトムＦｒａｍａｔｏｍｅ 高エネルギー放射線撮影法用の検出器および関連の撮像アセンブリ

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006105597A (ja) * 2004-09-30 2006-04-20 Fuji Photo Film Co Ltd 放射線像変換パネル
JP2007314709A (ja) * 2006-05-29 2007-12-06 Konica Minolta Medical & Graphic Inc 金属酸化物蛍光体、その製造方法、及びそれを用いた放射線用シンチレータプレート

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62173100U (https=) 1986-04-21 1987-11-04
WO2013051165A1 (ja) * 2011-10-03 2013-04-11 株式会社 東芝 Ｘ線検出器用増感紙、ｘ線検出器、およびｘ線検査装置
JP2020517960A (ja) * 2017-04-28 2020-06-18 フラマトムＦｒａｍａｔｏｍｅ 高エネルギー放射線撮影法用の検出器および関連の撮像アセンブリ

Also Published As

Publication number Publication date
JPWO2024024771A1 (https=) 2024-02-01
CN119631145A (zh) 2025-03-14
EP4563673A1 (en) 2025-06-04
US20250164651A1 (en) 2025-05-22

Similar Documents

Publication Publication Date Title
KR950007525B1 (ko) X선검출기 및 x선 검사장치
CN103140898B (zh) X射线检测器用增光纸、x射线检测器、以及x射线检查装置
US10830911B2 (en) Wavelength-shifting sheet-coupled scintillation detectors
JP2020060590A (ja) 波長シフトファイバ結合シンチレーション検出器を用いるｘ線検査
JP3332200B2 (ja) Ｘ線ｃｔ用放射線検出器
US7138633B1 (en) Apparatus employing a filtered scintillator and method of using same
CN101598799B (zh) 一种切伦科夫探测器及利用其进行检测的方法
US4317037A (en) Radiation detection apparatus
JPS58136687A (ja) 検出器列の製造方法
JP2928677B2 (ja) Ｘ線検出器およびｘ線検査装置
JP6105833B2 (ja) Ｘ線検出器及びｘ線検査装置
JPWO2016167334A1 (ja) 放射線像変換スクリーン、フラットパネルディテクタ、放射線検出装置、及びシンチレータ
WO2024024771A1 (ja) Ｘ線蛍光板、ｘ線検出器およびそれを用いたｘ線検査装置
JPH11281795A (ja) 放射線像変換パネル
WO2007106333A2 (en) Scintillator with improved light collection
Morlotti X-ray efficiency and modulation transfer function of fluorescent rare earth screens, determined by the Monte Carlo method
US2666856A (en) X-ray fluorescent response intensifier
US11181649B2 (en) Fluorescent screen, x-ray detector, and x-ray inspection apparatus
WO2012104798A2 (en) Radiation sensitive imaging detector including a radiation hard wavelength shifter
JP2018189425A (ja) Ｘ線像変換スクリーン、ｘ線撮影装置、及びｘ線検査装置
JP6957422B2 (ja) 蛍光板及びｘ線検査装置
CN216797665U (zh) 探测器及医疗影像设备
JP2017012593A (ja) 放射線像変換スクリーン及び放射線検出装置
JP2004109118A (ja) 放射線像変換パネルおよび放射線画像情報読取方法
JP2018077214A (ja) Ｘ線像変換スクリーン、フラットパネルディテクタ、及びｘ線検査装置

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: 23846501

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 2024537736

Country of ref document: JP

WWE Wipo information: entry into national phase

Ref document number: 202380056569.7

Country of ref document: CN

WWE Wipo information: entry into national phase

Ref document number: 2023846501

Country of ref document: EP

NENP Non-entry into the national phase

Ref country code: DE

ENP Entry into the national phase

Ref document number: 2023846501

Country of ref document: EP

Effective date: 20250226

WWP Wipo information: published in national office

Ref document number: 202380056569.7

Country of ref document: CN

WWP Wipo information: published in national office

Ref document number: 2023846501

Country of ref document: EP