1. A method of making a scintillator product, comprising:

(1) cutting a scintillator parent material;

(2) and (3) carrying out heat treatment on the product in the last step in an oxygen-containing atmosphere, wherein the temperature of the heat treatment is 1000-1500 ℃, and the heat preservation time of the heat treatment is 1-10 hours.

2. The method of claim 1, step (1) further comprising:

and applying a glue material on any surface of the cut scintillator.

3. The method according to claim 1, wherein in step (1), the cutting forms a slit on the scintillator parent material, and step (1) further comprises applying a glue material in the slit.

4. The method of claim 3, the slits penetrate or do not penetrate the scintillator parent material.

5. The method according to any one of claims 2 to 4, wherein the adhesive material comprises an inorganic adhesive;

preferably, the inorganic adhesive is selected from one or more of a silicate adhesive, an aluminosilicate adhesive or a borate adhesive.

6. The method according to any one of claims 2 to 4, wherein the glue material further comprises a reflective material,

preferably, the reflective material is selected from one or more of magnesium oxide, titanium dioxide, aluminium oxide and barium sulphate.

7. The method according to claim 1, wherein the volume content of oxygen in the oxygen-containing atmosphere is 5-50%, such as 10-30%;

preferably, the remaining gas in the oxygen-containing atmosphere other than oxygen is a gas that does not substantially chemically react with the scintillator;

preferably, the gas remaining in the oxygen-containing atmosphere other than oxygen is selected from one or more of nitrogen, carbon dioxide and an inert gas;

preferably, the water content of the oxygen-containing atmosphere is less than or equal to 5 percent;

preferably, the oxygen-containing atmosphere is air.

8. The method of claim 1, the scintillator product being a scintillator array.

9. The method of claim 1, the scintillator being an inorganic scintillator;

preferably, the scintillator is a ceramic scintillator;

preferably, the scintillator is a rare earth doped oxide, sulfide or oxysalt.

Preferably, the scintillator is selected from one or more of GOS scintillator, LSO scintillator, CWO scintillator.

10. A scintillator product obtained by the process of any one of claims 1 to 9.

Background

A scintillator is an element that converts high-energy rays into visible light. The scintillator is made into a scintillator array, and the scintillator array is matched with a detector array and a photoelectric conversion device for use, so that the scintillator detector can be obtained. When a particle enters the scintillator, atoms or molecules of the scintillator are excited to produce fluorescence, and the detector array can collect the generated visible photons and convert the photons into a measurable electrical signal by the photoelectric conversion device.

The scintillator detector can be applied to the fields of radiation imaging security inspection and medical treatment, and can be used for devices such as an X-ray computed tomography (X-CT) scanner, a Positron Emission Tomography (PET) scanner, an X-ray of a line scanning imaging mode, a gamma ray ionizing radiation imaging detector and the like.

Disclosure of Invention

The inventors found that the light output performance of the scintillator is degraded by the cutting process. The inventors have further found that the light output performance of the scintillator can be recovered and even improved by subjecting the cut scintillator to a heat treatment at 1000 ℃ or higher for 1 to 10 hours in an oxygen-containing atmosphere.

In some aspects, there is provided a method of making a scintillator product, comprising:

(1) cutting a scintillator parent material;

(2) and (3) performing heat treatment on the product in the last step in an oxygen-containing atmosphere, wherein the temperature of the heat treatment is 1000-1500 ℃ (for example, 1000-1100 ℃, for example 1100-1200 ℃, for example 1200-1300 ℃, for example 1300-1400 ℃, for example 1400-1500 ℃), and the heat preservation time of the heat treatment is 1-10 hours (for example, 1-2 hours, for example 2-5 hours, for example 5-10 hours).

In some embodiments, step (1) further comprises: and applying a glue material on any surface of the cut scintillator.

In some embodiments, the cutting method can be selected from, but not limited to, diamond single line cutting, multi-line cutting, cylindrical cutting, laser cutting, and the like.

In some embodiments, the step (1) of cutting forms a slit on the scintillator parent material, and the step (1) further comprises applying a glue material in the slit.

In some embodiments, the slits penetrate or do not penetrate the scintillator parent material.

In some embodiments, the glue comprises an inorganic adhesive.

In some embodiments, the inorganic binder is selected from one or more of a silicate binder, an aluminosilicate binder, or a borate binder.

In some embodiments, the glue also contains a reflective material.

In some embodiments, the reflective material is a white powder that does not chemically react with the glue.

In some embodiments, the reflective material is selected from one or more of magnesium oxide, titanium dioxide (titanium dioxide), aluminum oxide, and barium sulfate.

In some embodiments, the volume content of oxygen in the oxygen-containing atmosphere is 5 to 50%, such as 5 to 10%, 10 to 20%, 20 to 30%, 30 to 40%, 40 to 50%, or 10 to 30%.

In some embodiments, the remaining gases in the oxygen-containing atmosphere other than oxygen are gases that do not substantially chemically react with the scintillator.

In some embodiments, the remaining gas in the oxygen-containing atmosphere other than oxygen is selected from one or more of nitrogen, carbon dioxide, and an inert gas.

In some embodiments, the oxygen-containing atmosphere is air.

In some embodiments, the moisture content of the oxygen-containing atmosphere is less than 5%.

In some embodiments, the scintillator product is a scintillator array.

In some aspects, a scintillator product is provided, obtained by a method of any of the above.

Preferably, the scintillator product is a one-dimensional scintillator array (linear arrangement) or a two-dimensional scintillator array (planar arrangement).

In some embodiments, the disclosed methods further comprise curing the glue after applying the glue. The solidification mode can comprise drying solidification, melting solidification or water solidification and the like.

In some embodiments, the glue material may be an air-dried inorganic adhesive. The adhesive refers to the adhesive in which moisture or other solvents in an adhesive system naturally volatilize in the air and are cured to form a bond. For example, an alkali metal silicate-based adhesive, commonly referred to as water glass, may be represented by the general molecular formula: m₂O·nSiO₂And M represents metal ions such as potassium, sodium, lithium and the like.

In some embodiments, the glue material can be obtained by adding a curing agent and a filler to a base material such as silicate, aluminosilicate, borate, or the like.

In some embodiments, the binder may be sodium silicate waterglass (Na)₂O·nSiO₂). The curing agent can be silicon dioxide, magnesium oxide, zinc oxide, aluminum hydroxide, fluorosilicate, silicate, phosphate. The filler may be a white inorganic powder such as alumina, barium sulfate, titanium dioxide, and the like.

In some embodiments, the filler has a coefficient of thermal expansion that is 80 to 120%, such as 90 to 110%, such as 95 to 105%, times the coefficient of expansion of the scintillator.

In some embodiments, the glue material may be a water-curable inorganic adhesive, i.e., a substance that combines with water to form and cure. Examples of such a cement include portland cement, aluminum-inorganic-binder-acid-salt cement, magnesia cement, and gypsum.

In some embodiments, the adhesive material may be a hot-melt inorganic adhesive, i.e., a material that is heated to a melting temperature (or a flowing temperature) and then becomes a molten state (or a flowing state), and then wets the surface of the adherend, and after cooling and solidification, the adhesive material can achieve the purpose of bonding.

In some embodiments, the melting temperature of the glue material is close to the temperature (e.g., T) used to heat treat the scintillator_{Temperature of heat treatment}+/-100 ℃) and the glue material has stable chemical property and no decomposition at the heat treatment temperature and still has adhesive force.

In some embodiments, the paste contains a powder of a Zn-Al-B-K-Na-Si-O glass ceramic. When the scintillator adhesive is used, the inorganic adhesive powder is filled into a seam, the temperature is raised to be higher than the melting temperature of the inorganic hot melt adhesive, and then the scintillator on the two sides of the seam is bonded by cooling and solidifying.

In some embodiments, the glue may be any of the materials described in the following documents that can withstand a heat treatment at 1000 ℃: the plum red is strongly woven, the principle and the technology of gluing and the application [ M ]. Guangzhou: university of south china publisher, 2014.01. This document is incorporated herein in its entirety.

In some embodiments, the thermally treated scintillator array is encapsulated by a conventional method with an outer reflective layer to obtain a finished scintillator.

In some embodiments, the outer reflective layer is a glue, such as a resin (e.g., epoxy, polyester, silicone, etc.), that contains a reflective material (e.g., white inorganic powder, such as one or more of magnesium oxide, titanium dioxide, aluminum oxide, and barium sulfate).

In some embodiments, the method of encapsulating the outer reflector is described in chinese patent CN209580556U, which is incorporated herein in its entirety.

In some embodiments, as illustrated in the flow chart of fig. 1, a scintillator array is prepared using the following method

a1) Cutting a scintillator base material into a block shape, applying a glue material on the scintillator base material to form a glue layer, then placing another scintillator base material on the glue layer, repeating the steps for multiple times, and finally curing to obtain a structure-layer stacked structure formed by stacking a plurality of scintillator layers as shown in (I) of fig. 1.

a2) Cutting the above layer stack structure into pieces in a direction perpendicular to the glue layer, resulting in a structure-bar stack structure formed by stacking a plurality of scintillator bars as shown in fig. 1 (II);

a3) cutting the strip stacking structure into strips along a direction perpendicular to the glue layer to obtain a structure-block stacking structure formed by stacking a plurality of scintillator pixel blocks shown in (III) of fig. 1, namely a one-dimensional scintillator array;

a4) and carrying out heat treatment on the block stacked structure, wherein the heat treatment atmosphere is oxygen-containing atmosphere, the heat treatment temperature is 1000 ℃, and the heat preservation time is 1-10 hours (for example, 1-2 hours, for example, 2-5 hours, for example, 5-10 hours).

In some embodiments, as shown in fig. 2, a scintillator array is prepared using the following method:

b1) cutting the scintillator substrate 10 from the massive scintillator parent material, and then bonding and fixing the scintillator substrate 10 on the bottom plate 20;

b2) then cutting the scintillator substrate 10 to form one or more cutting seams 11 on the surface of the scintillator substrate 10, and then cleaning; the slits 11 divide the scintillator substrate 10 into a plurality of scintillator pixel blocks;

b2) and (3) pouring a glue material into the cutting seam 11, then solidifying, and adhering the scintillator pixel blocks on two sides of the cutting seam by the solidified glue material to form a glue layer positioned between the scintillator pixel blocks.

b3) Cutting one or more one-dimensional scintillator arrays 14 from the product of step b2 in a direction perpendicular to the slits 11;

b4) the one-dimensional scintillator array 14 is subjected to heat treatment in an oxygen-containing atmosphere at 1000 ℃ for 1 to 10 hours (e.g., 1 to 2 hours, e.g., 2 to 5 hours, e.g., 5 to 10 hours).

In some embodiments, the depth of the kerf can be greater than the thickness of the scintillator substrate, extending completely through the scintillator; the depth of the slit can also be less than the thickness of the scintillator substrate, so that the bottom of the scintillator remains partially connected.

In some embodiments, the scintillator is an inorganic scintillator.

In some embodiments, the scintillator is a ceramic scintillator.

In some embodiments, the scintillator is a rare earth doped oxide, sulfide, or oxysalt.

In some embodiments, the scintillator is selected from one or more of a GOS scintillator, a LSO scintillator, a CWO scintillator.

In some embodiments, the material of the scintillator comprises Gd₂O₂S system ceramic (GOS for short) and Lu₂SiO₅System crystal or ceramic (LSO for short) and CdWO₄System crystal or ceramic (CWO for short), etc.

In some embodiments, the scintillator product (e.g., scintillator array) prepared by the disclosed method can be used in an X-ray and gamma-ray ionizing radiation imaging detector device for X-ray computed tomography (X-CT) and/or Positron Emission Tomography (PET) and/or line scan imaging modes, and can be suitable for radiation imaging security inspection and medical treatment.

Description of terms:

if the following terms are used in the present invention, they may have the following meanings:

various relative terms such as "front," "back," "top," and "bottom," "upper," "lower," "above," "below," and the like may be used to facilitate description of various embodiments. Relative terms are defined with respect to conventional orientations of the structure and do not necessarily indicate an actual orientation of the structure at the time of manufacture or use. The following detailed description is, therefore, not to be taken in a limiting sense. As used in the description and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

The term "scintillator" refers to a material that emits light (e.g., visible light) in response to excitation by high-energy radiation (e.g., X, alpha, beta, or gamma radiation).

The term "high energy radiation" may refer to electromagnetic radiation having higher energy than ultraviolet radiation, including, but not limited to, X-radiation (i.e., X-ray radiation), alpha (α) particles, gamma (γ) radiation, and beta (β) radiation. In some embodiments, high energy radiation refers to gamma rays, cosmic rays, X-rays, and/or particles having an energy of 1keV or greater. The scintillator product as described herein may be used as a component of a radiation detector in devices such as counters, image intensifiers, and Computed Tomography (CT) scanners.

The term "soak time" for the heat treatment step is the time maintained at the heat treatment temperature.

Advantageous effects

One or more technical schemes of the present disclosure have one or more of the following beneficial effects:

(1) the method can improve the light output effect of the scintillator product;

(2) the scintillator products of the present disclosure have enhanced light output effects.

Drawings

FIG. 1 is a schematic illustration of a scintillator product manufacturing process according to one embodiment;

FIG. 2 is a schematic view of a scintillator substrate of example 1 after first cutting;

fig. 3 is a schematic diagram of a one-dimensional scintillator array of example 1.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to examples, but those skilled in the art will appreciate that the following examples are only illustrative of the present invention and should not be construed as limiting the scope of the present invention. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available.

Example 1

The scintillator material of example 1 was GOS ceramic. An array of scintillator arrays is prepared using a bulk scintillator master material, as shown in FIG. 2, by the following method:

1. providing a block-shaped scintillator parent material, and cutting a scintillator substrate 10 with the size of 26mm multiplied by 75mm multiplied by 2.9mm from the block-shaped scintillator parent material;

2. bonding the scintillator substrate 10 on the bottom plate 20, cutting the scintillator substrate 10 for the first time by using a multi-wire cutting machine along the direction of the edge with the length of 75mm of the scintillator substrate 10, and then cleaning;

wherein, a plurality of first slits 11 parallel to each other are formed on the scintillator substrate 10 by the first cutting, the first slits 11 divide the scintillator substrate 10 into a plurality of scintillator strips 13 arranged parallel to each other, the width of the first slits 11 is 0.2mm, and the width of the scintillator strips is 1.38 mm;

3. pouring a glue material containing a reflective material into the first slit 11, then placing the glue material in a vacuum environment to degas the glue material, and then placing the glue material in a baking oven at 120 ℃ for 4 hours to solidify the glue material, wherein the solidified glue material is the reflective layer 15 positioned in the first slit 11;

the formula of the glue material containing the reflecting material is as follows:

	water glass	Barium sulfate	Titanium white powder	Water (W)
					Concentration wt%	～13	～26	～24	～37

Cutting the scintillator substrate 10 obtained in the previous step for the second time along the direction perpendicular to the direction of the first cutting, and then cleaning; the second cutting further forms a plurality of second cutting lines 12 which are parallel to each other on the scintillator substrate 10, and the second cutting lines 12 divide the scintillator substrate 10 into a plurality of one-dimensional scintillator arrays 14 which are arranged in parallel to each other;

as shown in fig. 3, one-dimensional scintillator array 14 is formed by sixteen scintillator pixel blocks 16 arranged in a row; each scintillator pixel block 16 has a length (r) of 1.38mm, a thickness (d) of 1.5mm, and a width (w) of 2.9 mm; a reflecting layer 15 is arranged between two adjacent scintillator pixel blocks 16; the thickness of the reflective layer 15 is 0.2 mm; the one-dimensional scintillator array 14 has a total length (L) of 25.08mm and a pixel center-to-center distance of 1.58 mm.

4. Separating a one-dimensional scintillator array 14 from a bottom plate 20, then placing the one-dimensional scintillator array in an alumina crucible, then placing the alumina crucible in a muffle furnace (the inner wall of the muffle furnace is an alumina insulating brick) for heat treatment, wherein the heat treatment atmosphere is air (the water content is less than 5%), heating the temperature from room temperature to the target temperature of the heat treatment for 1000 ℃ in 120 minutes, keeping the temperature for 120 minutes, then cooling the temperature to 800 ℃ in 240 minutes, and finally cooling the temperature to room temperature along with the furnace to obtain the heat-treated scintillator array.

5. The one-dimensional scintillator array after heat treatment was subjected to conventional outer reflection layer preparation, in which the outer reflection layer covered only five of the six faces of the one-dimensional scintillator, leaving one face (L × w face) uncovered. The glue material used for preparing the outer reflecting layer is glue containing epoxy resin and titanium dioxide (the content of the titanium dioxide in the glue is 50 wt%), and the thickness of the outer reflecting layer is 0.2mm, so that the scintillator product-packaged one-dimensional scintillator array in the embodiment 1 is obtained.

Example 2

Embodiment 2 differs from embodiment 1 in the pixel size, and the specific size parameters of embodiment 2 are as follows: the one-dimensional scintillator array 14 has a total length (L) of 48mm, a pixel center-to-center distance of 3mm, a thickness (d) of 1.5mm, and a width (w) of 5.8 mm.

Comparative examples 1 to 2

The difference between the processes of comparative examples 1-2 and examples 1-2 is that the glue material containing the reflective material poured between the pixels in step 3 is organic glue containing epoxy resin and titanium dioxide (the content of titanium dioxide in the glue is 50 wt%), and the heat treatment procedure in step 4 is not implemented, but the outer reflective layer in step 5 is prepared after being directly cleaned.

Analyzing and detecting:

the effect of light output of the scintillator array products of the two-size example process and comparative example process of examples 1 and 2 were examined using the PMT method and the SiPM method, respectively. The PMT method test standard refers to the national standard GBT 13181 and 2002 scintillator performance measurement, and the radioactive source is a Cs-137 gamma source; the SiPM method is to replace a PMT with an SiPM device as a scintillation light detection device. The results are shown in table 1:

TABLE 1

It can be seen from the table that no matter what test method is adopted, the light output of the scintillator prepared by the process of the method is remarkably improved, the improvement amplitude can reach 9% -18.6%, and the smaller the pixel size (as the size of the embodiment 1), the more remarkable the improvement of the light output of the packaging method is.

While specific embodiments of the invention have been described in detail, those skilled in the art will understand that: various modifications may be made in the details within the teachings of the disclosure, and these variations are within the scope of the invention. The full scope of the invention is given by the appended claims and any equivalents thereof.