WO2018159194A1 - Glass for radiation detection - Google Patents

Glass for radiation detection Download PDF

Info

Publication number
WO2018159194A1
WO2018159194A1 PCT/JP2018/003035 JP2018003035W WO2018159194A1 WO 2018159194 A1 WO2018159194 A1 WO 2018159194A1 JP 2018003035 W JP2018003035 W JP 2018003035W WO 2018159194 A1 WO2018159194 A1 WO 2018159194A1
Authority
WO
WIPO (PCT)
Prior art keywords
glass
radiation
sio
content
fluorescence
Prior art date
Application number
PCT/JP2018/003035
Other languages
French (fr)
Japanese (ja)
Inventor
光 池田
克 岩尾
慎護 中根
高山　佳久
良憲 山▲崎▼
Original Assignee
日本電気硝子株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP2017111420A external-priority patent/JP7397565B2/en
Application filed by 日本電気硝子株式会社 filed Critical 日本電気硝子株式会社
Priority to EP18760417.8A priority Critical patent/EP3590903A4/en
Priority to US16/486,171 priority patent/US10800699B2/en
Publication of WO2018159194A1 publication Critical patent/WO2018159194A1/en

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C3/00—Glass compositions
    • C03C3/04—Glass compositions containing silica
    • C03C3/062—Glass compositions containing silica with less than 40% silica by weight
    • C03C3/064—Glass compositions containing silica with less than 40% silica by weight containing boron
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C3/00—Glass compositions
    • C03C3/04—Glass compositions containing silica
    • C03C3/062—Glass compositions containing silica with less than 40% silica by weight
    • C03C3/064—Glass compositions containing silica with less than 40% silica by weight containing boron
    • C03C3/066—Glass compositions containing silica with less than 40% silica by weight containing boron containing zinc
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C3/00—Glass compositions
    • C03C3/12—Silica-free oxide glass compositions
    • C03C3/16—Silica-free oxide glass compositions containing phosphorus
    • C03C3/19—Silica-free oxide glass compositions containing phosphorus containing boron
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C4/00—Compositions for glass with special properties
    • C03C4/12—Compositions for glass with special properties for luminescent glass; for fluorescent glass
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
    • C09K11/08—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
    • C09K11/70—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing phosphorus
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01T—MEASUREMENT OF NUCLEAR OR X-RADIATION
    • G01T1/00—Measuring X-radiation, gamma radiation, corpuscular radiation, or cosmic radiation
    • G01T1/02—Dosimeters
    • G01T1/06—Glass dosimeters using colour change; including plastic dosimeters

Definitions

  • the present invention relates to a radiation detection glass suitable for measuring the dose equivalent of radiation.
  • Radiation detection glass is widely used as a detection substance for measuring the radiation exposure dose in fields dealing with radiation, such as the medical field and the nuclear field.
  • radiation refers to beta rays, gamma rays, X-rays, or the like.
  • phosphate glass containing silver ions is used for radiation detection glass.
  • this glass is irradiated with radiation, holes and electrons are generated in the glass, and the generated holes and electrons are captured by Ag + ions in the glass to become Ag 2+ and Ag 0 .
  • Ag 2+ and Ag 0 in the glass are excited by ultraviolet light having a wavelength of 300 to 400 nm, fluorescence is emitted (radioluminescence phenomenon, hereinafter referred to as “RPL phenomenon”).
  • the radiation dose can be measured by measuring the fluorescence intensity.
  • the fluorescence detection sensitivity with respect to the radiation dose of the glass varies depending on the composition of the glass.
  • the fluorescence center generated in the glass by the RPL phenomenon is stabilized by the interaction with the coordinating coordination atom, and the disappearance of the fluorescence center does not occur at room temperature. Therefore, the radiation dose can be measured over a long period of time.
  • disappears by heat processing it can be used repeatedly.
  • the radiation detection glass may be used in a high temperature and high humidity environment, and high weather resistance is required.
  • the weather resistance is poor, there is a problem that the fluorescence (hereinafter referred to as “pre-dose”) of the glass itself when not irradiated with radiation is increased, which hinders measurement of radiation dose. Furthermore, problems such as generation of cracks on the glass surface and generation of foreign matters occur.
  • Patent Document 1 has improved the weather resistance, but has a problem that the fluorescence detection sensitivity cannot be sufficiently secured.
  • an object of the present invention is to provide a radiation detection glass having high fluorescence detection sensitivity and high weather resistance.
  • the radiation detecting glass of the present invention is in mol%, SiO 2 + B 2 O 3 0.1-30%, SiO 2 0-20%, B 2 O 3 0-10%, P 2 O 5 40- 70%, Al 2 O 3 10-30%, Na 2 O 10-30%, Ag 2 O 0.01-2%.
  • the glass for radiation detection of the present invention preferably contains, in mol%, MgO 0 to 10% and ZnO 0 to 10%.
  • the glass for radiation detection of the present invention preferably has a molar ratio of P 2 O 5 / (SiO 2 + B 2 O 3 + Al 2 O 3 ) of 1.5 or more.
  • a glass for radiation detection having high fluorescence detection sensitivity and high weather resistance can be provided.
  • the glass for radiation detection of the present invention has a glass composition of mol%, SiO 2 + B 2 O 3 0.1-30%, SiO 2 0-20%, B 2 O 3 0-10%, P 2 O 5 40-70%, Al 2 O 3 10-30%, Na 2 O 10-30%, Ag 2 O 0.01-2%.
  • SiO 2 and B 2 O 3 are important components for increasing the weather resistance of the glass, and are components for increasing the fluorescence detection sensitivity.
  • the content of SiO 2 + B 2 O 3 is 0.1 to 30% from 0.3 to 25%, from 0.5 to 19% 0.7 to 17% 1-15%, in particular 1.5 to 10% is preferable.
  • SiO 2 + B 2 O 3 is too small, easy to weather resistance you are significantly reduced.
  • SiO 2 + B 2 O 3 is too large, in addition to being difficult to vitrify, weather resistance tends to decrease conversely.
  • SiO 2 + B 2 O 3 means the total amount of each content of SiO 2 and B 2 O 3 .
  • SiO 2 and B 2 O 3 are as follows.
  • SiO 2 is an important component for increasing the weather resistance of glass, and is a component for increasing fluorescence detection sensitivity and mechanical strength of glass.
  • the content of SiO 2 is 0-20%, 0.1-19%, 0.1-18%, 0.5-17%, 0.7-16%, 1-15%, especially 1.5 It is preferably ⁇ 10%. When the content of SiO 2 is too large, in addition to meltability it becomes difficult to vitrify reduced devitrification crystals cristobalite tends to precipitate.
  • B 2 O 3 is an important component for increasing the weather resistance of the glass and is a component for increasing the fluorescence detection sensitivity.
  • the content of B 2 O 3 is 0-10%, 0.1-10%, 0.1-9%, 0.5-8%, 0.7-7%, 1-6%, especially 1 It is preferably 5 to 5%.
  • the weather resistance tends to decrease conversely.
  • P 2 O 5 is a main component forming a glass skeleton.
  • the content of P 2 O 5 is 40 to 70%, preferably 45 to 67%, 47 to 65%, 50 to 63%, particularly preferably 55 to 63%.
  • the fluorescence detection sensitivity is likely to decrease, and the glass is likely to undergo phase separation and devitrification.
  • the content of P 2 O 5 is too large, the melting property becomes difficult to vitrify reduced.
  • P 2 O 5 / (SiO 2 + B 2 O 3 + Al 2 O 3 ) is preferably 1.5 or more, 1.6 or more, and particularly preferably 1.7 or more. If P 2 O 5 / (SiO 2 + B 2 O 3 + Al 2 O 3 ) is too small, phase separation or devitrification is likely to occur, and vitrification becomes difficult.
  • the upper limit of P 2 O 5 / (SiO 2 + B 2 O 3 + Al 2 O 3) is not particularly limited, P 2 O 5 / (SiO 2 + B 2 O 3 + Al 2 O 3) is too large vitrification Since it becomes difficult and the weather resistance tends to decrease, it is preferably 5 or less, 4.5 or less, particularly 4 or less. “P 2 O 5 / (SiO 2 + B 2 O 3 + Al 2 O 3 )” is a value obtained by dividing the content of P 2 O 5 by the total amount of SiO 2 , B 2 O 3 and Al 2 O 3. Point to.
  • P 2 O 5 / (B 2 O 3 + Al 2 O 3 ) is preferably 1.5 or more, 1.6 or more, and particularly preferably 1.7 or more. If P 2 O 5 / (B 2 O 3 + Al 2 O 3 ) is too small, phase separation and devitrification are likely to occur, and vitrification becomes difficult.
  • the upper limit of P 2 O 5 / (B 2 O 3 + Al 2 O 3 ) is not particularly limited, but practically, it is preferably 5 or less, 4.5 or less, particularly 4 or less. “P 2 O 5 / (B 2 O 3 + Al 2 O 3 )” indicates a value obtained by dividing the content of P 2 O 5 by the total amount of B 2 O 3 and Al 2 O 3 .
  • Na 2 O is a component that lowers the viscosity of the glass melt and remarkably increases the meltability, and also increases the fluorescence detection sensitivity.
  • the content of Na 2 O is 10 to 30%, preferably 11 to 28%, 13 to 27%, 14 to 26%, particularly preferably 15 to 25%.
  • the fluorescence detection sensitivity is liable to be lowered.
  • the weather resistance tends to decrease.
  • Ag 2 O is an important component for forming a fluorescence center by the RPL phenomenon.
  • the content of Ag 2 O is 0.01 to 2%, preferably 0.01 to 1%, particularly preferably 0.01 to 0.5%.
  • fluorescence detection sensitivity is liable to decrease.
  • the weather resistance tends to decrease when the content of Ag 2 O is too large.
  • the glass for radiation detection of the present invention can contain the following components in addition to the above components.
  • MgO is a component that improves the weather resistance of glass.
  • the MgO content is preferably 0 to 10%, 0 to 7%, particularly preferably 0 to 4%.
  • liquidus temperature will rise and devitrification crystals, such as magnesium phosphate, will precipitate easily.
  • ZnO is a component that suppresses phase separation and devitrification of glass.
  • the content of ZnO is preferably 0 to 10%, 0 to 7%, particularly preferably 0 to 4%. When there is too much content of ZnO, a weather resistance and fluorescence detection sensitivity will fall easily.
  • CaO, SrO and BaO are components that increase the weather resistance of the glass.
  • the content of CaO + SrO + BaO is preferably 0 to 15%, 0 to 10%, particularly preferably 0 to 5%. If the content of CaO + SrO + BaO is too large, the fluorescence detection sensitivity tends to be lowered, and the liquidus temperature is lowered, so that devitrified crystals such as phosphates are likely to precipitate.
  • the preferable range of content of CaO, SrO, and BaO is as follows.
  • the CaO content is preferably 0 to 15%, 0 to 10%, particularly preferably 0 to 5%.
  • the SrO content is preferably 0 to 15%, 0 to 10%, particularly preferably 0 to 5%.
  • the content of BaO is preferably 0 to 15%, 0 to 10%, particularly preferably 0 to 5%.
  • composition examples of the radiation detecting glass of the present invention in mol%, B 2 O 3 0.1 ⁇ 10%, P 2 O 5 40 ⁇ 70%, Al 2 O 3 10 ⁇ 30%, Examples thereof include those containing 10 to 30% Na 2 O and 0.01 to 2% Ag 2 O.
  • the glass for radiation detection of the present invention preferably has a glass transition point of 600 ° C. or lower, 550 ° C. or lower, particularly 530 ° C. or lower. If the glass transition point is too high, the heat treatment temperature to be described later becomes high, so that B 2 O 3 , P 2 O 5 , and Na 2 O evaporate during the heat treatment, and composition deviation tends to occur, making it difficult to obtain desired characteristics. .
  • the lower limit of the glass transition point is not particularly limited, but is practically 300 ° C. or higher.
  • the raw material powder prepared to have a desired composition is melted until a homogeneous glass is obtained.
  • quartz glass, refractory, glassy carbon, metals such as platinum and gold, etc. can be used as the glass melting container.
  • the molten glass is poured onto a carbon plate or the like, formed into a plate shape, and then gradually cooled to room temperature.
  • the slow cooling conditions for example, it is preferable to lower the temperature from about 20 ° C. higher than the slow cooling point at about 2 ° C./min. In this way, a radiation detection glass can be obtained.
  • the obtained glass for radiation detection can be used for personal dose measurement and radiation measurement in the environment.
  • the oxygen partial pressure at the time of melting becomes low, the Ag component is easily reduced, and Ag 0 is easily generated in the glass.
  • the pre-dose value increases and the fluorescence detection sensitivity tends to decrease. Therefore, in order to suppress the reduction of the Ag component, it is desirable to lower the melting temperature to 1000 to 1400 ° C. or to use nitrate which is an oxidizing agent as a raw material.
  • nitrate silver nitrate, aluminum nitrate, sodium nitrate, or the like can be used.
  • both surfaces of the obtained radiation detection glass are polished so as to be optically polished surfaces (mirror surfaces), and then heat-treated, so that the fluorescence centers formed by natural radiation disappear.
  • the radiation dose received by the radiation detection glass is measured. Specifically, when radiation is applied to the radiation detection glass, Ag 2+ and Ag 0 are formed in the glass. Thereafter, heat treatment is performed under the following heat treatment conditions to stabilize the fluorescence intensity, and then ultraviolet light is irradiated to measure the fluorescence intensity. The radiation dose is calculated from this fluorescence intensity.
  • the heat treatment temperature is preferably (glass transition point / 4) to (glass transition point / 2.5), particularly (glass transition point / 3.5) to (glass transition point / 2.7). If the heat treatment temperature is too low, the fluorescence intensity is difficult to stabilize and the reproducibility of the radiation dose measurement value tends to be low. On the other hand, if the heat treatment temperature is too high, the fluorescence intensity tends to decrease during long-term storage, and the reproducibility of the radiation dose measurement values tends to be low. Specifically, the heat treatment temperature is preferably 105 to 200 ° C., particularly 110 to 180 ° C. The heat treatment time is preferably 10 to 120 minutes, particularly 20 to 70 minutes.
  • the heat treatment time is too short, heat is not easily transmitted to the inside of the glass, so that the fluorescence intensity is difficult to stabilize and the reproducibility of the radiation dose measurement value tends to be low.
  • the heat treatment time is too long, the fluorescence intensity tends to decrease during long-term storage, and the reproducibility of the radiation dose measurement value tends to be low.
  • the heat treatment temperatures are (glass transition point-80 ° C) to (glass transition point-10 ° C), (glass transition point-55 ° C) to (glass transition point-15 ° C), (glass transition point-40 ° C) to ( It is preferable that the glass transition point is -15 ° C, particularly (glass transition point -25 ° C) to (glass transition point -20 ° C).
  • the heat treatment temperature is too low, the fluorescent centers formed in the glass are not easily lost, and it is difficult to regenerate the glass.
  • the heat treatment temperature is too high, the silver ion concentration on the glass surface increases and the glass tends to be altered, making it difficult to regenerate the glass.
  • the heat treatment temperature is preferably 420 to 500 ° C., 430 to 490 ° C., 440 to 480 ° C., particularly 450 to 470 ° C.
  • the heat treatment time is preferably 20 to 150 minutes, 30 to 120 minutes, 40 to 90 minutes, particularly 50 to 70 minutes. If the heat treatment time is too short, heat is not easily transmitted to the inside of the glass, so that the fluorescence centers formed in the glass are not easily lost and the glass is difficult to regenerate. On the other hand, if the heat treatment time is too long, the concentration of silver ions on the glass surface increases and the glass tends to be altered, making it difficult to regenerate the glass. In addition, it becomes possible to use repeatedly by reproducing
  • glass containing SiO 2 or B 2 O 3 tends to be insufficiently regenerated by heat treatment. This is considered to be because when the glass contains SiO 2 or B 2 O 3 , the viscosity becomes high and the movement of holes and electrons is hindered, so that Ag 2+ and Ag 0 are difficult to return to Ag + . Then, the glass containing SiO 2 or B 2 O 3 is heat-treated at a relatively high temperature as described above, thereby reducing the viscosity of the glass and activating the movement of holes and electrons. As a result, Ag 2+ and Ag 0 can be sufficiently returned to Ag + , and the radiation detection glass can be regenerated.
  • Tables 1 and 2 show the glass composition, fluorescence detection sensitivity, and weather resistance of Examples (No. 1 to 15) and Comparative Example (No. 16) of the present invention.
  • the high-purity raw materials used for normal glass such as oxides, hydroxides, carbonates, nitrates, phosphates, etc., corresponding to the raw materials of each component, so as to be the glass composition in the table
  • the glass batch weighed and mixed uniformly was put into a quartz glass crucible and melted in an electric furnace at 1000 to 1300 ° C. for 1 to 5 hours until a homogeneous glass was obtained.
  • stirring was performed at the time of melting for the purpose of homogenizing the glass and blowing bubbles.
  • the molten glass was poured out on a carbon plate, formed into a plate shape, and then gradually cooled from a temperature about 20 ° C. above the annealing point to room temperature at 2 ° C./min.
  • the weather resistance and the fluorescence detection sensitivity after irradiating a predetermined radiation dose were evaluated.
  • the pre-dose value was used for the weather resistance evaluation.
  • the sample which polished both surfaces to become an optical polishing surface was subjected to ultrasonic cleaning and dried at 120 ° C. for 10 minutes to obtain a sample before the test. Then, it left still for 40 hours in the environment of temperature 50 degreeC and humidity 95%, and the sample after a test was obtained.
  • the change in the pre-dose value was calculated as [pre-dose value after test] / [pre-dose value before test].
  • the fluorescence detection sensitivity For the evaluation of the fluorescence detection sensitivity, a sample whose both surfaces were polished so as to be an optically polished surface (mirror surface) was used. The sample was heat treated at 400 ° C. for 1 hour to eliminate the fluorescence center formed by natural radiation, and then irradiated with about 1 Gy of X-rays from the direction perpendicular to the optical polishing surface of the sample. After the X-ray irradiation, heat treatment was performed at 100 ° C. for 30 minutes, and after the generation of the fluorescence center was completed, the fluorescence intensity measured by irradiating the optically polished surface of the sample with ultraviolet light was defined as the fluorescence detection sensitivity.
  • the values of the fluorescence detection sensitivity described in the table are No. It is a relative value when the fluorescence intensity of 16 samples is 1.
  • Samples 1 to 15 had high fluorescence detection sensitivity of 1.5 to 3.1. No. Samples 1 to 15 had a high change in pre-dose value of 1.15 or less and high weather resistance. On the other hand, No. which is a comparative example. Sample 16 had a large change in pre-dose value of 2.24, so the weather resistance was low, and the fluorescence detection sensitivity was also low.
  • the glass for radiation detection according to the present invention is suitable as a glass used for personal radiation dosimeters for radiation, radiation measurement in the environment, monitoring of patient exposure during radiation therapy, and the like.
  • radiation refers to beta rays, gamma rays, X-rays, or the like.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Inorganic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Molecular Biology (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Glass Compositions (AREA)

Abstract

Provided is a glass for radiation detection having high fluorescence detection sensitivity and high weather resistance. The glass for radiation detection is characterized by containing, in mol%, 0.1-30% of SiO2+B2O3, 0-20% of SiO2, 0-10% of B2O3, 40-70% of P2O5, 10-30% of Al2O3, 10-30% of Na2O, and 0.01-2% of Ag2O.

Description

放射線検出用ガラスRadiation detection glass
　本発明は放射線の線量当量を計測するために好適な放射線検出用ガラスに関する。 The present invention relates to a radiation detection glass suitable for measuring the dose equivalent of radiation.
　放射線検出用ガラスは、放射線被ばく線量を測定するための検出物質として、医療分野、原子力分野等の放射線を取り扱う分野において広く用いられている。なお、ここで放射線とはベータ線、ガンマ線またはエックス線等を指す。一般に放射線検出用ガラスには、例えば、銀イオンを含有したリン酸塩ガラスが用いられている。このガラスに放射線を照射すると、ガラス中に正孔と電子が生成し、生成した正孔と電子がガラス中のＡｇ＋イオンに捕捉されてＡｇ２＋、Ａｇ０となる。ガラス中のＡｇ２＋、Ａｇ０を、波長３００～４００ｎｍの紫外光により励起すると蛍光を発する（ラジオフォトルミネッセンス現象、以下「ＲＰＬ現象」と示す。）。 Radiation detection glass is widely used as a detection substance for measuring the radiation exposure dose in fields dealing with radiation, such as the medical field and the nuclear field. Here, radiation refers to beta rays, gamma rays, X-rays, or the like. In general, for example, phosphate glass containing silver ions is used for radiation detection glass. When this glass is irradiated with radiation, holes and electrons are generated in the glass, and the generated holes and electrons are captured by Ag + ions in the glass to become Ag 2+ and Ag 0 . When Ag 2+ and Ag 0 in the glass are excited by ultraviolet light having a wavelength of 300 to 400 nm, fluorescence is emitted (radioluminescence phenomenon, hereinafter referred to as “RPL phenomenon”).
　ＲＰＬ現象による蛍光強度は照射された放射線の線量当量（以下、「放射線量」と記す。）に比例するので、蛍光強度を測定する事により放射線量を計測する事が出来る。このガラスの放射線量に対する蛍光検出感度は、ガラスの組成に応じて変化する。ＲＰＬ現象によってガラス中に生成した蛍光中心は近接配位原子との相互作用により安定化し、室温下では蛍光中心の消失が起こらないため、長期間にわたり放射線量の計測が可能である。また、ガラス中に生成した蛍光中心は加熱処理により消失するため、繰り返して使用することが可能である。 Since the fluorescence intensity due to the RPL phenomenon is proportional to the dose equivalent (hereinafter referred to as “radiation dose”) of the irradiated radiation, the radiation dose can be measured by measuring the fluorescence intensity. The fluorescence detection sensitivity with respect to the radiation dose of the glass varies depending on the composition of the glass. The fluorescence center generated in the glass by the RPL phenomenon is stabilized by the interaction with the coordinating coordination atom, and the disappearance of the fluorescence center does not occur at room temperature. Therefore, the radiation dose can be measured over a long period of time. Moreover, since the fluorescence center produced | generated in glass lose | disappears by heat processing, it can be used repeatedly.
　ところで、放射線検出用ガラスは、高温高湿環境下で使用される場合があり、高い耐候性が必要になる。耐候性が悪いと、放射線未照射時にガラス自身が有する蛍光（以下、「プレドーズ」と示す。）が増加し、放射線量の計測を阻害する問題がある。更に、ガラス表面のひび割れや異物の発生等の問題が生じる。 By the way, the radiation detection glass may be used in a high temperature and high humidity environment, and high weather resistance is required. When the weather resistance is poor, there is a problem that the fluorescence (hereinafter referred to as “pre-dose”) of the glass itself when not irradiated with radiation is increased, which hinders measurement of radiation dose. Furthermore, problems such as generation of cracks on the glass surface and generation of foreign matters occur.
　そこで、放射線検出用ガラスの耐候性を向上させるために、例えば特許文献１には、オルトリン酸アルミニウム等を原料として使用することが開示されている。 Therefore, in order to improve the weather resistance of the radiation detecting glass, for example, Patent Document 1 discloses the use of aluminum orthophosphate as a raw material.
特公平０２－０２５８５１号公報Japanese Patent Publication No. 02-025851
　特許文献１に記載されているガラスは、耐候性の向上を図っているが蛍光検出感度が十分に確保できないという問題があった。 The glass described in Patent Document 1 has improved the weather resistance, but has a problem that the fluorescence detection sensitivity cannot be sufficiently secured.
　以上に鑑み、本発明は、高い蛍光検出感度及び高い耐候性を有する放射線検出用ガラスを提供することを目的とする。 In view of the above, an object of the present invention is to provide a radiation detection glass having high fluorescence detection sensitivity and high weather resistance.
　本発明者等は、種々の実験を繰り返した結果、ガラス組成を厳密に規制することにより上記技術的課題を解決しえることを見出した。 As a result of repeating various experiments, the present inventors have found that the above technical problem can be solved by strictly regulating the glass composition.
　即ち、本発明の放射線検出用ガラスは、モル％で、ＳｉＯ２＋Ｂ２Ｏ３　０．１～３０％、ＳｉＯ２　０～２０％、Ｂ２Ｏ３　０～１０％、Ｐ２Ｏ５　４０～７０％、Ａｌ２Ｏ３　１０～３０％、Ｎａ２Ｏ　１０～３０％、Ａｇ２Ｏ　０．０１～２％を含有することを特徴とする。 That is, the radiation detecting glass of the present invention is in mol%, SiO 2 + B 2 O 3 0.1-30%, SiO 2 0-20%, B 2 O 3 0-10%, P 2 O 5 40- 70%, Al 2 O 3 10-30%, Na 2 O 10-30%, Ag 2 O 0.01-2%.
　ガラス組成中にＡｇ２Ｏを導入することにより、高い蛍光検出感度を有しやすくなる。さらに、ガラス組成中にＳｉＯ２及び／またはＢ２Ｏ３と、Ａｌ２Ｏ３とを所定量導入することにより、蛍光検出感度を高い状態に保ちながら耐候性を高めやすくなる。 By introducing Ag 2 O into the glass composition, it becomes easy to have high fluorescence detection sensitivity. Furthermore, by introducing a predetermined amount of SiO 2 and / or B 2 O 3 and Al 2 O 3 into the glass composition, it becomes easy to improve the weather resistance while maintaining a high fluorescence detection sensitivity.
　本発明の放射線検出用ガラスは、モル％で、さらにＭｇＯ　０～１０％、ＺｎＯ　０～１０％を含有することが好ましい。 The glass for radiation detection of the present invention preferably contains, in mol%, MgO 0 to 10% and ZnO 0 to 10%.
　本発明の放射線検出用ガラスは、モル比で、Ｐ２Ｏ５／（ＳｉＯ２＋Ｂ２Ｏ３＋Ａｌ２Ｏ３）が１．５以上であることが好ましい。 The glass for radiation detection of the present invention preferably has a molar ratio of P 2 O 5 / (SiO 2 + B 2 O 3 + Al 2 O 3 ) of 1.5 or more.
　本発明によれば、高い蛍光検出感度及び高い耐候性を有する放射線検出用ガラスを提供することができる。 According to the present invention, a glass for radiation detection having high fluorescence detection sensitivity and high weather resistance can be provided.
　本発明の放射線検出用ガラスは、ガラス組成として、モル％で、ＳｉＯ２＋Ｂ２Ｏ３　０．１～３０％、ＳｉＯ２　０～２０％、Ｂ２Ｏ３　０～１０％、Ｐ２Ｏ５　４０～７０％、Ａｌ２Ｏ３　１０～３０％、Ｎａ２Ｏ　１０～３０％、Ａｇ２Ｏ　０．０１～２％を含有する。 The glass for radiation detection of the present invention has a glass composition of mol%, SiO 2 + B 2 O 3 0.1-30%, SiO 2 0-20%, B 2 O 3 0-10%, P 2 O 5 40-70%, Al 2 O 3 10-30%, Na 2 O 10-30%, Ag 2 O 0.01-2%.
　ガラス組成を上記のように限定した理由を以下に示す。なお、各成分の含有量の説明において、特に断りのない限り、「％」は「モル％」を意味する。 The reasons for limiting the glass composition as described above are shown below. In the description of the content of each component, “%” means “mol%” unless otherwise specified.
　ＳｉＯ２及びＢ２Ｏ３は、ガラスの耐候性を高めるために重要な成分であり、また蛍光検出感度を高める成分である。ＳｉＯ２＋Ｂ２Ｏ３の含有量は０．１～３０％であり、０．３～２５％、０．５～１９％、０．７～１７％、１～１５％、特に１．５～１０％であることが好ましい。ＳｉＯ２＋Ｂ２Ｏ３の含有量が少なすぎると、耐候性が著しく低下し易い。ＳｉＯ２＋Ｂ２Ｏ３の含有量が多すぎると、ガラス化し難くなることに加えて、逆に耐候性が低下し易くなる。なお、「ＳｉＯ２＋Ｂ２Ｏ３」は、ＳｉＯ２及びＢ２Ｏ３の各含有量の合量を意味する。 SiO 2 and B 2 O 3 are important components for increasing the weather resistance of the glass, and are components for increasing the fluorescence detection sensitivity. The content of SiO 2 + B 2 O 3 is 0.1 to 30% from 0.3 to 25%, from 0.5 to 19% 0.7 to 17% 1-15%, in particular 1.5 to 10% is preferable. When the content of SiO 2 + B 2 O 3 is too small, easy to weather resistance you are significantly reduced. When the content of SiO 2 + B 2 O 3 is too large, in addition to being difficult to vitrify, weather resistance tends to decrease conversely. “SiO 2 + B 2 O 3 ” means the total amount of each content of SiO 2 and B 2 O 3 .
　ＳｉＯ２及びＢ２Ｏ３の好ましい範囲は以下の通りである。 Preferred ranges for SiO 2 and B 2 O 3 are as follows.
　ＳｉＯ２は、ガラスの耐候性を高めるために重要な成分であり、また蛍光検出感度、ガラスの機械的強度を高める成分である。ＳｉＯ２の含有量は０～２０％であり、０．１～１９％、０．１～１８％、０．５～１７％、０．７～１６％、１～１５％、特に１．５～１０％であることが好ましい。ＳｉＯ２の含有量が多過ぎると、溶融性が低下しガラス化し難くなることに加えて、クリストバライト等の失透結晶が析出し易くなる。 SiO 2 is an important component for increasing the weather resistance of glass, and is a component for increasing fluorescence detection sensitivity and mechanical strength of glass. The content of SiO 2 is 0-20%, 0.1-19%, 0.1-18%, 0.5-17%, 0.7-16%, 1-15%, especially 1.5 It is preferably ˜10%. When the content of SiO 2 is too large, in addition to meltability it becomes difficult to vitrify reduced devitrification crystals cristobalite tends to precipitate.
　Ｂ２Ｏ３は、ガラスの耐候性を高めるために重要な成分であり、また蛍光検出感度を高める成分である。Ｂ２Ｏ３の含有量は０～１０％であり、０．１～１０％、０．１～９％、０．５～８％、０．７～７％、１～６％、特に１．５～５％であることが好ましい。Ｂ２Ｏ３の含有量が多過ぎると、分相によってガラス化し難くなることに加えて、逆に耐候性が低下し易くなる。 B 2 O 3 is an important component for increasing the weather resistance of the glass and is a component for increasing the fluorescence detection sensitivity. The content of B 2 O 3 is 0-10%, 0.1-10%, 0.1-9%, 0.5-8%, 0.7-7%, 1-6%, especially 1 It is preferably 5 to 5%. When the content of B 2 O 3 is too large, in addition to being difficult to vitrification by phase separation, the weather resistance tends to decrease conversely.
　Ｐ２Ｏ５は、ガラスの骨格を形成する主成分である。Ｐ２Ｏ５の含有量は４０～７０％であり、４５～６７％、４７～６５％、５０～６３％、特に５５～６３％であることが好ましい。Ｐ２Ｏ５の含有量が少な過ぎると、蛍光検出感度の低下が起こり易く、またガラスが分相、失透し易くなる。一方、Ｐ２Ｏ５の含有量が多過ぎると、溶融性が低下しガラス化し難くなる。 P 2 O 5 is a main component forming a glass skeleton. The content of P 2 O 5 is 40 to 70%, preferably 45 to 67%, 47 to 65%, 50 to 63%, particularly preferably 55 to 63%. When the content of P 2 O 5 is too small, the fluorescence detection sensitivity is likely to decrease, and the glass is likely to undergo phase separation and devitrification. On the other hand, when the content of P 2 O 5 is too large, the melting property becomes difficult to vitrify reduced.
　Ａｌ２Ｏ３は、ガラスの耐候性を高める成分であると共に、分相、失透を抑制する成分である。Ａｌ２Ｏ３の含有量は１０～３０％であり、１１～２８％、１３～２６％、１４～２４％、特に１５～２３％であることが好ましい。Ａｌ２Ｏ３の含有量が少な過ぎると、耐候性が低下し易くなる。一方、Ａｌ２Ｏ３の含有量が多過ぎると、溶融性が低下しガラス化し難くなる。 Al 2 O 3 is a component that enhances the weather resistance of glass and a component that suppresses phase separation and devitrification. The content of Al 2 O 3 is 10 to 30%, preferably 11 to 28%, 13 to 26%, 14 to 24%, particularly preferably 15 to 23%. When the content of Al 2 O 3 is too small, the weather resistance tends to decrease. On the other hand, when the content of Al 2 O 3 is too large, the melting property becomes difficult to vitrify reduced.
　Ｐ２Ｏ５／（ＳｉＯ２＋Ｂ２Ｏ３＋Ａｌ２Ｏ３）は１．５以上、１．６以上、特に１．７以上であることが好ましい。Ｐ２Ｏ５／（ＳｉＯ２＋Ｂ２Ｏ３＋Ａｌ２Ｏ３）が小さ過ぎると分相や失透が起り易くなって、ガラス化し難くなる。また、Ｐ２Ｏ５／（ＳｉＯ２＋Ｂ２Ｏ３＋Ａｌ２Ｏ３）の上限は特に限定されないが、Ｐ２Ｏ５／（ＳｉＯ２＋Ｂ２Ｏ３＋Ａｌ２Ｏ３）が大き過ぎるとガラス化し難くなったり、耐候性が低下し易くなるため、５以下、４．５以下、特に４以下であることが好ましい。なお、「Ｐ２Ｏ５／（ＳｉＯ２＋Ｂ２Ｏ３＋Ａｌ２Ｏ３）」はＰ２Ｏ５の含有量をＳｉＯ２、Ｂ２Ｏ３及びＡｌ２Ｏ３の合量で除した値を指す。 P 2 O 5 / (SiO 2 + B 2 O 3 + Al 2 O 3 ) is preferably 1.5 or more, 1.6 or more, and particularly preferably 1.7 or more. If P 2 O 5 / (SiO 2 + B 2 O 3 + Al 2 O 3 ) is too small, phase separation or devitrification is likely to occur, and vitrification becomes difficult. The upper limit of P 2 O 5 / (SiO 2 + B 2 O 3 + Al 2 O 3) is not particularly limited, P 2 O 5 / (SiO 2 + B 2 O 3 + Al 2 O 3) is too large vitrification Since it becomes difficult and the weather resistance tends to decrease, it is preferably 5 or less, 4.5 or less, particularly 4 or less. “P 2 O 5 / (SiO 2 + B 2 O 3 + Al 2 O 3 )” is a value obtained by dividing the content of P 2 O 5 by the total amount of SiO 2 , B 2 O 3 and Al 2 O 3. Point to.
　なお、Ｐ２Ｏ５／（Ｂ２Ｏ３＋Ａｌ２Ｏ３）は１．５以上、１．６以上、特に１．７以上であることが好ましい。Ｐ２Ｏ５／（Ｂ２Ｏ３＋Ａｌ２Ｏ３）が小さ過ぎると分相や失透が起り易くなって、ガラス化し難くなる。また、Ｐ２Ｏ５／（Ｂ２Ｏ３＋Ａｌ２Ｏ３）の上限は特に限定されないが、現実的には、５以下、４．５以下、特に４以下であることが好ましい。なお、「Ｐ２Ｏ５／（Ｂ２Ｏ３＋Ａｌ２Ｏ３）」はＰ２Ｏ５の含有量をＢ２Ｏ３及びＡｌ２Ｏ３の合量で除した値を指す。 P 2 O 5 / (B 2 O 3 + Al 2 O 3 ) is preferably 1.5 or more, 1.6 or more, and particularly preferably 1.7 or more. If P 2 O 5 / (B 2 O 3 + Al 2 O 3 ) is too small, phase separation and devitrification are likely to occur, and vitrification becomes difficult. In addition, the upper limit of P 2 O 5 / (B 2 O 3 + Al 2 O 3 ) is not particularly limited, but practically, it is preferably 5 or less, 4.5 or less, particularly 4 or less. “P 2 O 5 / (B 2 O 3 + Al 2 O 3 )” indicates a value obtained by dividing the content of P 2 O 5 by the total amount of B 2 O 3 and Al 2 O 3 .
　Ｎａ２Ｏはガラス融液の粘度を下げて、溶融性を顕著に高める成分であると共に、蛍光検出感度を高める成分である。Ｎａ２Ｏの含有量は１０～３０％であり、１１～２８％、１３～２７％、１４～２６％、特に１５～２５％であることが好ましい。Ｎａ２Ｏの含有量が少な過ぎると、溶融性が低下し易くなることに加えて、蛍光検出感度が低下しやすくなる。一方、Ｎａ２Ｏの含有量が多過ぎると、耐候性が低下し易くなる。 Na 2 O is a component that lowers the viscosity of the glass melt and remarkably increases the meltability, and also increases the fluorescence detection sensitivity. The content of Na 2 O is 10 to 30%, preferably 11 to 28%, 13 to 27%, 14 to 26%, particularly preferably 15 to 25%. When the content of Na 2 O is too small, in addition to the meltability being easily lowered, the fluorescence detection sensitivity is liable to be lowered. On the other hand, when the content of Na 2 O is too large, the weather resistance tends to decrease.
　Ａｇ２ＯはＲＰＬ現象によって蛍光中心を形成するための重要な成分である。Ａｇ２Ｏの含有量は、０．０１～２％であり、０．０１～１％、特に０．０１～０．５％であることが好ましい。Ａｇ２Ｏの含有量が少な過ぎると蛍光検出感度が低下し易くなる。一方、Ａｇ２Ｏの含有量が多過ぎると耐候性が低下し易くなる。 Ag 2 O is an important component for forming a fluorescence center by the RPL phenomenon. The content of Ag 2 O is 0.01 to 2%, preferably 0.01 to 1%, particularly preferably 0.01 to 0.5%. When the content of Ag 2 O is too small fluorescence detection sensitivity is liable to decrease. On the other hand, the weather resistance tends to decrease when the content of Ag 2 O is too large.
　本発明の放射線検出用ガラスは、上記成分以外にも以下の成分を含有することができる。 The glass for radiation detection of the present invention can contain the following components in addition to the above components.
　ＭｇＯはガラスの耐候性を高める成分である。ＭｇＯの含有量は０～１０％、０～７％、特に０～４％であることが好ましい。ＭｇＯの含有量が多過ぎると、液相温度が上昇して、リン酸マグネシウム等の失透結晶が析出し易くなる。 MgO is a component that improves the weather resistance of glass. The MgO content is preferably 0 to 10%, 0 to 7%, particularly preferably 0 to 4%. When there is too much content of MgO, liquidus temperature will rise and devitrification crystals, such as magnesium phosphate, will precipitate easily.
　ＺｎＯはガラスの分相、失透を抑制する成分である。ＺｎＯの含有量は０～１０％、０～７％、特に０～４％であることが好ましい。ＺｎＯの含有量が多過ぎると、耐候性、蛍光検出感度が低下し易くなる。 ZnO is a component that suppresses phase separation and devitrification of glass. The content of ZnO is preferably 0 to 10%, 0 to 7%, particularly preferably 0 to 4%. When there is too much content of ZnO, a weather resistance and fluorescence detection sensitivity will fall easily.
　ＣａＯ、ＳｒＯ及びＢａＯはガラスの耐候性を高める成分である。ＣａＯ＋ＳｒＯ＋ＢａＯの含有量は０～１５％、０～１０％、特に０～５％であることが好ましい。ＣａＯ＋ＳｒＯ＋ＢａＯの含有量が多すぎると蛍光検出感度が低下し易くなり、また液相温度が低下して、リン酸塩等の失透結晶が析出し易くなる。 CaO, SrO and BaO are components that increase the weather resistance of the glass. The content of CaO + SrO + BaO is preferably 0 to 15%, 0 to 10%, particularly preferably 0 to 5%. If the content of CaO + SrO + BaO is too large, the fluorescence detection sensitivity tends to be lowered, and the liquidus temperature is lowered, so that devitrified crystals such as phosphates are likely to precipitate.
　なお、ＣａＯ、ＳｒＯ及びＢａＯの含有量の好ましい範囲は以下の通りである。 In addition, the preferable range of content of CaO, SrO, and BaO is as follows.
　ＣａＯの含有量は０～１５％、０～１０％、特に０～５％であることが好ましい。 The CaO content is preferably 0 to 15%, 0 to 10%, particularly preferably 0 to 5%.
　ＳｒＯの含有量は０～１５％、０～１０％、特に０～５％であることが好ましい。 The SrO content is preferably 0 to 15%, 0 to 10%, particularly preferably 0 to 5%.
　ＢａＯの含有量は０～１５％、０～１０％、特に０～５％であることが好ましい。 The content of BaO is preferably 0 to 15%, 0 to 10%, particularly preferably 0 to 5%.
　なお、本発明の放射線検出用ガラスの具体的な組成例として、モル％で、Ｂ２Ｏ３　０．１～１０％、Ｐ２Ｏ５　４０～７０％、Ａｌ２Ｏ３　１０～３０％、Ｎａ２Ｏ　１０～３０％、Ａｇ２Ｏ　０．０１～２％を含有するものが挙げられる。 As specific composition examples of the radiation detecting glass of the present invention, in mol%, B 2 O 3 0.1 ~ 10%, P 2 O 5 40 ~ 70%, Al 2 O 3 10 ~ 30%, Examples thereof include those containing 10 to 30% Na 2 O and 0.01 to 2% Ag 2 O.
　本発明の放射線検出用ガラスは、ガラス転移点が６００℃以下、５５０℃以下、特に５３０℃以下であることが好ましい。ガラス転移点が高すぎると、後述する熱処理温度が高くなるため、熱処理時にＢ２Ｏ３、Ｐ２Ｏ５、Ｎａ２Ｏが蒸発し組成ズレが起こりやすくなり、所望の特性が得られにくくなる。ガラス転移点の下限は特に限定されないが、現実的には３００℃以上である。 The glass for radiation detection of the present invention preferably has a glass transition point of 600 ° C. or lower, 550 ° C. or lower, particularly 530 ° C. or lower. If the glass transition point is too high, the heat treatment temperature to be described later becomes high, so that B 2 O 3 , P 2 O 5 , and Na 2 O evaporate during the heat treatment, and composition deviation tends to occur, making it difficult to obtain desired characteristics. . The lower limit of the glass transition point is not particularly limited, but is practically 300 ° C. or higher.
　次に本発明の放射線検出用ガラスの製造方法について説明する。 Next, a method for producing the radiation detecting glass of the present invention will be described.
　まず、所望の組成になるように調合した原料粉末を、均質なガラスが得られるまで溶融する。ここで、ガラス溶融用容器としては、石英ガラス、耐火物、グラッシーカーボン、白金や金等の金属等が使用できる。次いで、溶融ガラスをカーボン板等の上に流し出し、板状に成形した後、常温まで徐冷する。徐冷条件としては、例えば、徐冷点より約２０℃高い温度から約２℃／分で降温することが好ましい。このようにして、放射線検出用ガラスを得ることができる。得られた放射線検出用ガラスは、個人被ばく線量計測、環境中の放射線計測に用いることができる。 First, the raw material powder prepared to have a desired composition is melted until a homogeneous glass is obtained. Here, quartz glass, refractory, glassy carbon, metals such as platinum and gold, etc. can be used as the glass melting container. Next, the molten glass is poured onto a carbon plate or the like, formed into a plate shape, and then gradually cooled to room temperature. As the slow cooling conditions, for example, it is preferable to lower the temperature from about 20 ° C. higher than the slow cooling point at about 2 ° C./min. In this way, a radiation detection glass can be obtained. The obtained glass for radiation detection can be used for personal dose measurement and radiation measurement in the environment.
　なお、溶融時の酸素分圧が低くなるとＡｇ成分が還元され易くなり、ガラス中にＡｇ０が生成しやすくなる。ガラス中にＡｇ０が多く存在すると、プレドーズ値が高くなり、蛍光検出感度が低下し易くなる。そこで、Ａｇ成分の還元を抑制するために、溶融温度を１０００～１４００℃と低くするか、または、原料として酸化剤である硝酸塩を使用することが望ましい。なお、硝酸塩としては、硝酸銀、硝酸アルミニウム、硝酸ナトリウム等を用いることができる。 In addition, when the oxygen partial pressure at the time of melting becomes low, the Ag component is easily reduced, and Ag 0 is easily generated in the glass. When a large amount of Ag 0 is present in the glass, the pre-dose value increases and the fluorescence detection sensitivity tends to decrease. Therefore, in order to suppress the reduction of the Ag component, it is desirable to lower the melting temperature to 1000 to 1400 ° C. or to use nitrate which is an oxidizing agent as a raw material. As the nitrate, silver nitrate, aluminum nitrate, sodium nitrate, or the like can be used.
　次に、放射線検出用ガラスを用いて蛍光強度測定を行った後、再生する一連の流れについて説明する。 Next, a description will be given of a series of flow of regeneration after performing fluorescence intensity measurement using radiation detection glass.
　（自然放射線による蛍光中心の消失）
　まず、得られた放射線検出用ガラスの両面を光学研磨面（鏡面）となるように研磨した後、熱処理し、自然放射線によって形成された蛍光中心を消失させる。 (Disappearance of fluorescent center by natural radiation)
First, both surfaces of the obtained radiation detection glass are polished so as to be optically polished surfaces (mirror surfaces), and then heat-treated, so that the fluorescence centers formed by natural radiation disappear.
　（放射線量の測定）
　続いて、放射線検出用ガラスが受けた放射線量を測定する。具体的には、放射線検出用ガラスに放射線が照射されると、ガラス中にＡｇ２＋、Ａｇ０が形成される。その後、下記の熱処理条件で熱処理し蛍光強度を安定化した後、紫外光を照射して蛍光強度を測定する。この蛍光強度から放射線量を算出する。 (Measurement of radiation dose)
Subsequently, the radiation dose received by the radiation detection glass is measured. Specifically, when radiation is applied to the radiation detection glass, Ag 2+ and Ag 0 are formed in the glass. Thereafter, heat treatment is performed under the following heat treatment conditions to stabilize the fluorescence intensity, and then ultraviolet light is irradiated to measure the fluorescence intensity. The radiation dose is calculated from this fluorescence intensity.
　熱処理温度は、（ガラス転移点／４）～（ガラス転移点／２．５）、特に（ガラス転移点／３．５）～（ガラス転移点／２．７）であることが好ましい。熱処理温度が低すぎると、蛍光強度が安定化しにくく、放射線量測定値の再現性が低くなり易い。一方、熱処理温度が高すぎると、長期保管時に蛍光強度が低下し易く、放射線量測定値の再現性が低くなり易い。具体的には、熱処理温度は、１０５～２００℃、特に１１０～１８０℃であることが好ましい。また、熱処理時間は、１０～１２０分、特に２０～７０分であることが好ましい。熱処理時間が短過ぎると、ガラス内部にまで熱が伝わりにくいため、蛍光強度が安定化しにくく、放射線量測定値の再現性が低くなり易い。一方、熱処理時間が長過ぎると、長期保管時に蛍光強度が低下し易く、放射線量測定値の再現性が低くなり易い。 The heat treatment temperature is preferably (glass transition point / 4) to (glass transition point / 2.5), particularly (glass transition point / 3.5) to (glass transition point / 2.7). If the heat treatment temperature is too low, the fluorescence intensity is difficult to stabilize and the reproducibility of the radiation dose measurement value tends to be low. On the other hand, if the heat treatment temperature is too high, the fluorescence intensity tends to decrease during long-term storage, and the reproducibility of the radiation dose measurement values tends to be low. Specifically, the heat treatment temperature is preferably 105 to 200 ° C., particularly 110 to 180 ° C. The heat treatment time is preferably 10 to 120 minutes, particularly 20 to 70 minutes. If the heat treatment time is too short, heat is not easily transmitted to the inside of the glass, so that the fluorescence intensity is difficult to stabilize and the reproducibility of the radiation dose measurement value tends to be low. On the other hand, if the heat treatment time is too long, the fluorescence intensity tends to decrease during long-term storage, and the reproducibility of the radiation dose measurement value tends to be low.
　（ガラスの再生）
　蛍光強度測定後のガラスを下記の熱処理条件で熱処理することにより、ガラスを再生（再利用）することができる。 (Regeneration of glass)
By heat-treating the glass after the fluorescence intensity measurement under the following heat treatment conditions, the glass can be regenerated (reused).
　熱処理温度は、（ガラス転移点－８０℃）～（ガラス転移点－１０℃）、（ガラス転移点－５５℃）～（ガラス転移点－１５℃）、（ガラス転移点－４０℃）～（ガラス転移点－１５℃）、特に（ガラス転移点－２５℃）～（ガラス転移点－２０℃）であることが好ましい。熱処理温度が低すぎると、ガラス中に形成された蛍光中心を十分に消失させにくく、ガラスを再生し難くなる。一方、熱処理温度が高すぎると、ガラス表面の銀イオン濃度が高まりガラスが変質しやすくなるため、ガラスを再生し難くなる。具体的には、熱処理温度は、４２０～５００℃、４３０～４９０℃、４４０～４８０℃、特に４５０～４７０℃であることが好ましい。また、熱処理時間は、２０～１５０分、３０～１２０分、４０～９０分、特に５０～７０分であることが好ましい。熱処理時間が短過ぎると、ガラス内部にまで熱が伝わりにくいため、ガラス中に形成された蛍光中心を十分に消失させにくく、ガラスを再生し難くなる。一方、熱処理時間が長過ぎると、ガラス表面の銀イオン濃度が高まりガラスが変質しやすくなるため、ガラスを再生し難くなる。なお、ガラスを再生することにより、繰り返し使用することが可能になる。使用回数が多いほど、コストダウンに繋がることは言うまでもない。なお、自然放射線によって形成された蛍光中心を消失させる際の熱処理条件も上記と同様にすることが好ましい。 The heat treatment temperatures are (glass transition point-80 ° C) to (glass transition point-10 ° C), (glass transition point-55 ° C) to (glass transition point-15 ° C), (glass transition point-40 ° C) to ( It is preferable that the glass transition point is -15 ° C, particularly (glass transition point -25 ° C) to (glass transition point -20 ° C). When the heat treatment temperature is too low, the fluorescent centers formed in the glass are not easily lost, and it is difficult to regenerate the glass. On the other hand, if the heat treatment temperature is too high, the silver ion concentration on the glass surface increases and the glass tends to be altered, making it difficult to regenerate the glass. Specifically, the heat treatment temperature is preferably 420 to 500 ° C., 430 to 490 ° C., 440 to 480 ° C., particularly 450 to 470 ° C. The heat treatment time is preferably 20 to 150 minutes, 30 to 120 minutes, 40 to 90 minutes, particularly 50 to 70 minutes. If the heat treatment time is too short, heat is not easily transmitted to the inside of the glass, so that the fluorescence centers formed in the glass are not easily lost and the glass is difficult to regenerate. On the other hand, if the heat treatment time is too long, the concentration of silver ions on the glass surface increases and the glass tends to be altered, making it difficult to regenerate the glass. In addition, it becomes possible to use repeatedly by reproducing | regenerating glass. It goes without saying that the more the number of uses, the lower the cost. In addition, it is preferable that the heat treatment conditions for erasing the fluorescent center formed by natural radiation are the same as described above.
　ちなみに、ＳｉＯ２またはＢ２Ｏ３を含有するガラスは熱処理によるガラスの再生が不十分になり易い。これは、ガラスがＳｉＯ２またはＢ２Ｏ３を含有すると、粘度が高くなって正孔や電子の動きを妨げるため、Ａｇ２＋、Ａｇ０がＡｇ＋に戻り難くなるためであると考えられる。そこで、ＳｉＯ２またはＢ２Ｏ３を含有するガラスを上記の通り比較的高い温度で熱処理することで、ガラスの粘度を低下させ、正孔や電子の動きを活性化することができる。結果として、Ａｇ２＋、Ａｇ０をＡｇ＋に十分に戻すことができ、放射線検出用ガラスを再生することが可能になる。 Incidentally, glass containing SiO 2 or B 2 O 3 tends to be insufficiently regenerated by heat treatment. This is considered to be because when the glass contains SiO 2 or B 2 O 3 , the viscosity becomes high and the movement of holes and electrons is hindered, so that Ag 2+ and Ag 0 are difficult to return to Ag + . Then, the glass containing SiO 2 or B 2 O 3 is heat-treated at a relatively high temperature as described above, thereby reducing the viscosity of the glass and activating the movement of holes and electrons. As a result, Ag 2+ and Ag 0 can be sufficiently returned to Ag + , and the radiation detection glass can be regenerated.
　以下、本発明を実施例に基づいて説明する。なお、以下の実施例は単なる例示である。本発明は、以下の実施例に何ら限定されない。 Hereinafter, the present invention will be described based on examples. The following examples are merely illustrative. The present invention is not limited to the following examples.
　本発明の実施例（Ｎｏ．１～１５）及び比較例（Ｎｏ．１６）のガラスの組成、蛍光検出感度及び耐候性を表１及び２に示す。 Tables 1 and 2 show the glass composition, fluorescence detection sensitivity, and weather resistance of Examples (No. 1 to 15) and Comparative Example (No. 16) of the present invention.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　まず表中のガラス組成になるように、各成分の原料として各々相当する酸化物、水酸化物、炭酸塩、硝酸塩、リン酸塩等の通常のガラスに使用される高純度原料を選定し、秤量して均一に混合したガラスバッチを石英ガラスるつぼに投入し、電気炉にて１０００～１３００℃で１～５時間、均質なガラスが得られるまで溶融した。なお、ガラスの均質化及び泡切れ等を目的として、溶融時に攪拌を行った。次いで、溶融ガラスをカーボン板上に流し出し、板形状に成形した後、徐冷点より２０℃程度高い温度から２℃／分で常温まで徐冷した。得られた各試料について、耐候性と所定の放射線量を照射した後の蛍光検出感度を評価した。 First, select the high-purity raw materials used for normal glass such as oxides, hydroxides, carbonates, nitrates, phosphates, etc., corresponding to the raw materials of each component, so as to be the glass composition in the table, The glass batch weighed and mixed uniformly was put into a quartz glass crucible and melted in an electric furnace at 1000 to 1300 ° C. for 1 to 5 hours until a homogeneous glass was obtained. In addition, stirring was performed at the time of melting for the purpose of homogenizing the glass and blowing bubbles. Next, the molten glass was poured out on a carbon plate, formed into a plate shape, and then gradually cooled from a temperature about 20 ° C. above the annealing point to room temperature at 2 ° C./min. About each obtained sample, the weather resistance and the fluorescence detection sensitivity after irradiating a predetermined radiation dose were evaluated.
　耐候性の評価には、プレドーズ値を用いた。詳細には、両面を光学研磨面（鏡面）となるように研磨した試料を超音波洗浄し、１２０℃で１０分間乾燥させ、試験前の試料を得た。その後、温度５０℃、湿度９５％の環境下で４０時間静置し、試験後の試料を得た。試験前の試料の光学研磨面に紫外光を照射して測定した蛍光強度を［試験前のプレドーズ値］、試験後の試料の光学研磨面に紫外光を照射して測定した蛍光強度を［試験後のプレドーズ値］とした。プレドーズ値の変化を［試験後のプレドーズ値］／［試験前のプレドーズ値］として算出した。 The pre-dose value was used for the weather resistance evaluation. In detail, the sample which polished both surfaces to become an optical polishing surface (mirror surface) was subjected to ultrasonic cleaning and dried at 120 ° C. for 10 minutes to obtain a sample before the test. Then, it left still for 40 hours in the environment of temperature 50 degreeC and humidity 95%, and the sample after a test was obtained. The fluorescence intensity measured by irradiating the optically polished surface of the sample before the test with ultraviolet light [predose value before the test], and the fluorescence intensity measured by irradiating the optically polished surface of the sample after the test with ultraviolet light [testing] Later pre-dose value]. The change in the pre-dose value was calculated as [pre-dose value after test] / [pre-dose value before test].
　蛍光検出感度の評価には、両面を光学研磨面（鏡面）となるように研磨した試料を使用した。試料を４００℃で１時間熱処理する事で、自然放射線によって形成された蛍光中心を消失させた後、試料の光学研磨面の垂直方向から約１Ｇｙのエックス線を照射した。エックス線照射後に１００℃で３０分熱処理し、蛍光中心の生成が完了した後、試料の光学研磨面に紫外光を照射して測定した蛍光強度を蛍光検出感度とした。なお、表に記載の蛍光検出感度の値は、Ｎｏ．１６の試料の蛍光強度を１としたときの相対値である。 For the evaluation of the fluorescence detection sensitivity, a sample whose both surfaces were polished so as to be an optically polished surface (mirror surface) was used. The sample was heat treated at 400 ° C. for 1 hour to eliminate the fluorescence center formed by natural radiation, and then irradiated with about 1 Gy of X-rays from the direction perpendicular to the optical polishing surface of the sample. After the X-ray irradiation, heat treatment was performed at 100 ° C. for 30 minutes, and after the generation of the fluorescence center was completed, the fluorescence intensity measured by irradiating the optically polished surface of the sample with ultraviolet light was defined as the fluorescence detection sensitivity. The values of the fluorescence detection sensitivity described in the table are No. It is a relative value when the fluorescence intensity of 16 samples is 1.
　表から明らかなように、本発明の実施例であるＮｏ．１～１５の試料は蛍光検出感度が１．５～３．１と高かった。また、Ｎｏ．１～１５の試料は、プレドーズ値の変化が１．１５以下と小さく、耐候性が高かった。一方、比較例であるＮｏ．１６の試料は、プレドーズ値の変化が２．２４と大きいため耐候性が低く、また、蛍光検出感度も低かった。 As is clear from the table, No. which is an example of the present invention. Samples 1 to 15 had high fluorescence detection sensitivity of 1.5 to 3.1. No. Samples 1 to 15 had a high change in pre-dose value of 1.15 or less and high weather resistance. On the other hand, No. which is a comparative example. Sample 16 had a large change in pre-dose value of 2.24, so the weather resistance was low, and the fluorescence detection sensitivity was also low.
　本発明の放射線検出用ガラスは、放射線の個人被ばく線量計、環境中の放射線計測、放射線治療時の患者の被ばく量モニタリング等に用いるガラスとして好適である。なお、ここで放射線とはベータ線、ガンマ線またはエックス線等を指す。 The glass for radiation detection according to the present invention is suitable as a glass used for personal radiation dosimeters for radiation, radiation measurement in the environment, monitoring of patient exposure during radiation therapy, and the like. Here, radiation refers to beta rays, gamma rays, X-rays, or the like.

Claims (3)

  1. 　モル％で、ＳｉＯ２＋Ｂ２Ｏ３　０．１～３０％、ＳｉＯ２　０～２０％、Ｂ２Ｏ３　０～１０％、Ｐ２Ｏ５　４０～７０％、Ａｌ２Ｏ３　１０～３０％、Ｎａ２Ｏ　１０～３０％、Ａｇ２Ｏ　０．０１～２％を含有することを特徴とする放射線検出用ガラス。 In mol%, SiO 2 + B 2 O 3 0.1-30%, SiO 2 0-20%, B 2 O 3 0-10%, P 2 O 5 40-70%, Al 2 O 3 10-30% , Na 2 O 10 ~ 30% , the radiation detecting glass characterized by containing Ag 2 O 0.01 ~ 2%.
  2. 　モル％で、さらにＭｇＯ　０～１０％、ＺｎＯ　０～１０％を含有することを特徴とする請求項１に記載の放射線検出用ガラス。 The glass for radiation detection according to claim 1, further comprising MgO 0 to 10% and ZnO 0 to 10% in mol%.
  3. 　モル比で、Ｐ２Ｏ５／（ＳｉＯ２＋Ｂ２Ｏ３＋Ａｌ２Ｏ３）が１．５以上であることを特徴とする請求項１又は２に記載の放射線検出用ガラス。 3. The glass for radiation detection according to claim 1, wherein P 2 O 5 / (SiO 2 + B 2 O 3 + Al 2 O 3 ) is 1.5 or more in terms of a molar ratio.
PCT/JP2018/003035 2017-02-28 2018-01-30 Glass for radiation detection WO2018159194A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP18760417.8A EP3590903A4 (en) 2017-02-28 2018-01-30 Glass for radiation detection
US16/486,171 US10800699B2 (en) 2017-02-28 2018-01-30 Glass for radiation detection

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP2017035685 2017-02-28
JP2017-035685 2017-02-28
JP2017111420A JP7397565B2 (en) 2017-02-28 2017-06-06 Radiation detection glass
JP2017-111420 2017-06-06

Publications (1)

Publication Number Publication Date
WO2018159194A1 true WO2018159194A1 (en) 2018-09-07

Family

ID=63371289

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2018/003035 WO2018159194A1 (en) 2017-02-28 2018-01-30 Glass for radiation detection

Country Status (1)

Country Link
WO (1) WO2018159194A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2021166569A1 (en) * 2020-02-17 2021-08-26 日本電気硝子株式会社 Glass dosimeter

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5010333B1 (en) * 1970-07-14 1975-04-21
JPS5438310A (en) * 1977-08-31 1979-03-22 Toshiba Kasei Kougiyou Kk Glass for dose meter
JPH0225851B2 (en) 1985-07-05 1990-06-06 Toshiba Glass Kk
JP2016145145A (en) * 2015-01-30 2016-08-12 Ａｇｃテクノグラス株式会社 Glass for fluorescent glass dosimeter

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5010333B1 (en) * 1970-07-14 1975-04-21
JPS5438310A (en) * 1977-08-31 1979-03-22 Toshiba Kasei Kougiyou Kk Glass for dose meter
JPH0225851B2 (en) 1985-07-05 1990-06-06 Toshiba Glass Kk
JP2016145145A (en) * 2015-01-30 2016-08-12 Ａｇｃテクノグラス株式会社 Glass for fluorescent glass dosimeter

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP3590903A4 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2021166569A1 (en) * 2020-02-17 2021-08-26 日本電気硝子株式会社 Glass dosimeter

Similar Documents

Publication Publication Date Title
US4212919A (en) Strengthened polychromatic glasses
JP5153963B2 (en) Glass for light guide fiber
JPWO2006107077A1 (en) UV transmitting glass composition and glass article using the same
JP2007137705A (en) Glass composition
GB2121784A (en) Scintillation glass
JPH0357059B2 (en)
JP6748435B2 (en) Fluorescent glass Dosimeter glass
JP7397565B2 (en) Radiation detection glass
ElBatal et al. γ-ray interaction with bioglasses containing transition metal ions
WO2018159194A1 (en) Glass for radiation detection
JP2016153784A (en) Glass for fluoroglass dosimeters
JP7094492B2 (en) Treatment method of glass for radiation detection
JP2018150190A (en) Glass for radiation detection
JP7022386B2 (en) Manufacturing method of glass for radiation detection
JP2018151367A (en) Regenerating method of radiation detection glass
JP6959564B2 (en) Radiation detection glass
JPH0940440A (en) Scintillator glass
JP7032697B2 (en) Manufacturing method of glass for radiation detection
JP2018150189A (en) Glass for radiation detection
JP2018150221A (en) Glass for radiation detection and method for producing the same
JP2018145083A (en) Radiation dose measuring method
JP2021128114A (en) Glass dosemeter
Hedden et al. Investigation of Some Glasses for High‐Level Gamma‐Radiation Dosimeters
JP2018158854A (en) Glass pane for radiation detection and method for producing the same
WO2020013005A1 (en) Gas detection material

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: 18760417

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

ENP Entry into the national phase

Ref document number: 2018760417

Country of ref document: EP

Effective date: 20190930