Pixel scintillation transparent ceramic and preparation method thereof

Abstract

The invention relates to pixelated flickering transparent ceramic and a preparation method thereof. The pixelated flickering transparent ceramic is composed of a plurality of flickering transparent ceramic pixels which are periodically arranged; the cross sectional area S of each flickering transparent ceramic pixel is 100 [mu] m < 2 >-0.25 mm < 2 >; the taper angle theta is 0-15 degrees; the height H of the material is 500-2000 [mu] m; the distance L between the adjacent flickering transparent ceramic pixels is 10-500 [mu] m; the flickering transparent ceramic pixel is in the shape of a column, a prismatic table and a circular truncated cone. The pixelated scintillation transparent ceramic is rare earth doped transparent ceramic and is selected from at least one of Y3Al5O12: RE, Lu2O3: RE, Y2O3: RE, Lu3Al5O12: RE, Gd3Al2Ga3O12: RE, Lu2Y2SiO5: RE, Gd2O2S: RE, La2Hf2O7: RE, Y2Hf2O7: RE, Gd2Hf2O7: RE and YVO4: RE, and the rare earth doped transparent ceramic is a rare earth doped transparent ceramic. Wherein RE is selected from at least one of Ce < 3 + >, Eu < 2 + >, Pr < 3 + >, Cr < 3 + >, Tb < 3 + >, Sm < 3 + >, Dy < 3 + >, Ho < 3 + > and Tm < 3 + >.

Description

Technical Field

[0001] The present invention relates to a pixelated scintillating transparent ceramic and a preparation method thereof, specifically to a pixelated scintillating transparent ceramic applied to a scintillation conversion screen and a preparation method thereof, and particularly to a method for improving the spatial resolution and radiation detection sensitivity of a scintillating transparent ceramic conversion screen, belonging to the field of high-energy X-ray imaging. Background Art

[0002] In high-energy X-ray imaging technology based on indirect X-ray detectors, the light conversion material is one of the cores and also a research hotspot in recent years. Its light yield, decay time, quantum efficiency, and luminescence stability under high-energy X-ray irradiation are directly related to the quality of the device. Inorganic luminescent scintillation conversion screens such as powders, thin films, bulk materials, and arrays have developed competitively, continuously promoting the improvement of the quality of X-ray detector devices. During this development process, pixelated scintillating transparent ceramics have stood out in the field of high-energy X-ray imaging due to their superior light yield and radiation detection sensitivity compared to traditional inorganic luminescent scintillation conversion screens such as powders, thin films, bulk materials, and arrays, and have become one of the excellent choices for scintillation conversion screens of current indirect X-ray detectors.

[0003] Traditional array scintillation conversion screens can reduce the lateral scattering of scintillation light, guide the scintillation light to exit along the direction of the pixel, improve the signal-to-noise ratio of the imaging signal, and thus improve the spatial resolution. However, the preparation process of traditional array scintillation conversion screens is relatively complex. Usually, pixels need to be prepared by wire cutting or laser processing methods and assembled to obtain an array scintillator. The complex processing and packaging processes result in high costs. More importantly, the pixel size obtained by wire cutting or laser processing methods usually cannot be lower than 0.5 mm. As indirect X-ray detector scintillation screens gradually develop towards fast decay, high light yield, high spatial resolution, and small size, higher requirements are put forward for the scintillation performance and preparation methods of array scintillation ceramics. It is particularly important to study new scintillation screens applied to high-energy X-rays and high spatial resolution. Chinese Patent Publication No. CN115636434A discloses a method for preparing a lead-free perovskite pixelated scintillating thin film. A pixelated flexible and bendable scintillating thin film with controllable size is prepared by a template-assisted method and a negative pressure filling method. The pixelated structure prepared by this method can avoid the lateral scattering of scintillation light and improve the spatial resolution of the scintillation screen. However, due to the existence of particles, there is a large attenuation in the transmission process of scintillation light within a single pixel, which greatly limits the detection sensitivity of the scintillator. Summary of the Invention

[0004] In view of the above problems, the object of the present invention is to provide a pixelated scintillating transparent ceramic and an integrated preparation method thereof. The pixelated pixels are arranged in an array. By controlling the cone angle of the pixels, the lateral scattering of the scintillation light can be reduced, so as to guide the scintillation light to exit along the pixel direction, effectively suppressing the optical crosstalk of the scintillation light during the light transmission process, and obtaining high spatial resolution and detection sensitivity.

[0005] On the one hand, the present invention provides a pixelated scintillating transparent ceramic, which is composed of a plurality of scintillating transparent ceramic pixels arranged periodically; the pixelated scintillating transparent ceramic is a rare earth doped transparent ceramic, selected from Y3Al5O 12 :RE, Lu2O3:RE, Y2O3:RE, Lu3Al5O 12 :RE, Gd3Al2Ga3O 12 :RE, Lu2Y2SiO5:RE, Gd2O2S:RE, La2Hf2O7:RE, Y2Hf2O7:RE, Gd2Hf2O7:RE, YVO4:RE; wherein RE is selected from Ce 3+ , Eu 2+ , Pr 3+ , Cr 3+ , Tb 3+ , Sm 3+ , Dy 3+ , Ho 3+ and Tm 3+ and at least one of them.

[0006] In the present invention, a pixelated scintillating transparent ceramic is prepared by constructing periodically arranged scintillating transparent ceramic pixels on a horizontal plane. Among them, the pixelated structure guides the scintillation light to a specific direction, reduces the optical crosstalk caused by light during transmission, effectively improves the signal-to-noise ratio of the ceramic scintillation conversion screen, and thus improves the spatial resolution of the pixelated scintillating transparent ceramic. At the same time, the pixelated scintillating transparent ceramic has a high visible light transmittance, and the thickness of the scintillator is not limited, thereby increasing the light yield and detection sensitivity.

[0007] Preferably, the doping amount of RE in the pixelated scintillating transparent ceramic is 0.1-5 mol%.

[0008] On the other hand, due to the high preparation cost of the traditional array-type scintillation conversion screen and the difficulty in preparing scintillating transparent ceramic pixels with a cross-sectional area of less than 0.25 mm 2 for the scintillating transparent ceramic pixels, therefore, the present invention also provides a preparation method of the above pixelated scintillating transparent ceramic, including: (1) Mixing the scintillating ceramic powder and the photosensitive resin to obtain a scintillating ceramic slurry; (2) Prepare a pixelated scintillating transparent ceramic green body using 3D printing technology; (3) Debind and sinter the obtained pixelated scintillating transparent ceramic green body to obtain a pixelated scintillating transparent ceramic biscuit; (4) Polish the pixelated scintillating transparent ceramic biscuit to obtain the pixelated scintillating transparent ceramic.

[0009] In the present invention, since a stereolithography 3D printing technology is used for the forming of the scintillating transparent ceramic, the digital projection system of the stereolithography 3D printing technology determines the minimum pixel cross-sectional area that can be achieved. The current horizontal resolution (X / Y axis) of the stereolithography 3D printing technology can reach 30 μm. On the other hand, by optimizing the composition of the scintillating ceramic slurry, the ceramic slurry in the present invention is more sensitive to the curing light, which is beneficial to the preparation of the pixelated structure. Therefore, the present invention can relatively easily achieve the preparation of a pixelated scintillating transparent ceramic with a pixel cross-sectional area of 0.25 mm 2 or less.

[0010] Preferably, in step (1), the scintillating ceramic powder accounts for 60 - 82 wt% of the total mass of the scintillating ceramic powder and the photosensitive resin, preferably 74 - 79 wt%; Preferably, the scintillating ceramic powder is at least one of Y3Al5O 12 :RE, Lu2O3:RE, Y2O3:RE, Lu3Al5O 12 :RE, Gd3Al2Ga3O 12 :RE, Lu2Y2SiO5:RE, Gd2O2S:RE, La2Hf2O7:RE, Y2Hf2O7:RE, Gd2Hf2O7:RE, YVO4:RE; where RE is selected from at least one of Ce 3+ , Eu 2+ , Pr 3+ , Cr 3+ , Tb 3+ , Sm 3+ , Dy 3+ , Ho 3+ and Tm 3+ .

[0011] Preferably, in step (1), the photosensitive resin comprises 70-85 wt% epoxy acrylate resin, 0.1-1 wt% photoinitiator, 12-25 wt% plasticizer and 1-6 wt% dispersant, and the sum of the mass percentages of each component is 100 wt%; preferably, the photoinitiator is at least one of 2,2-diethoxyacetophenone, 4-phenyldibenzoyl ketone, benzoyl chloride diphenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide; the plasticizer is at least one of polyethylene glycol, diethylhexyl phthalate, glycol benzoate, triisodecyl trimellitate; the dispersant is at least one of triethylhexyl phosphate, sodium dodecyl sulfate, methyl amyl alcohol, fatty acid polyethylene glycol ester.

[0012] Preferably, in step (2), the 3D printing technology includes: according to the array structure parameters of the pixelated scintillating transparent ceramic pixels, using computer-aided design to design the pixelated scintillating transparent ceramic model and import it into a 3D printer, and layer-by-layer printing the scintillating ceramic slurry under light.

[0013] Preferably, the array structure parameters of the pixelated scintillating transparent ceramic include: the cross-sectional area S of each scintillating transparent ceramic pixel is 100 μm 2 ~0.25 mm 2 , the cone angle θ is 0°-15°, the height H is 500-2000 μm; the distance L between adjacent scintillating transparent ceramic pixels is 10-500 μm; the configuration of the scintillating transparent ceramic pixel is columnar, frustum-shaped, truncated cone-shaped; the cross-sectional shape of the scintillating transparent ceramic pixel is square, regular hexagon, circular.

[0014] Preferably, the parameters of the 3D printing technology include: the single-layer thickness is 0.03-0.05 mm; the light intensity is 20-60 mW / cm 2 .

[0015] Preferably, in step (3), the temperature of the debinding is 800-1200 °C, the time is 1-5 hours, and the heating rate is 0.1-1 °C / minute.

[0016] Preferably, in step (3), the sintering method is vacuum sintering; the temperature of the vacuum sintering is 1650-1950 °C, the time is 1-20 hours, and the vacuum degree is not less than 10 -3 Pa.

[0017] In the present invention, due to the existence of the digital projection system, the 3D printing technology has a high resolution. By layer-by-layer curing the scintillating ceramic slurry through the photocuring technology, a single pixel cross-sectional area of 0.25 mm can be prepared after sintering 2The following pixelated scintillating transparent ceramics. In addition, the 3D printing technology of the present invention prepares pixelated scintillating transparent ceramics by curing a scintillating ceramic slurry. Since the scintillating ceramic slurry has a high solid content, transparent scintillating ceramics can be obtained.

[0018] Beneficial effects: In the present invention, a pixelated green body of scintillating transparent ceramics is constructed by 3D printing. After debinding and sintering, and through polishing treatment, the pixelated scintillating transparent ceramics can be integrally prepared. The pixelated scintillating transparent ceramics can reduce scintillation light scattering and make the scintillation light exit along the pixel direction, thereby reducing the optical crosstalk of the scintillation light during transmission in the transparent ceramics and improving the radiation detection sensitivity of the scintillation conversion screen, providing a novel structured scintillating ceramic material for high-energy X-ray high-resolution imaging of scintillating ceramics. Description of the drawings

[0019] Figure 1 Schematic diagram of the structure of the pixelated scintillating transparent ceramics prepared in Example 1; Figure 2 Schematic diagram of the conversion of X-rays to scintillation light for a single pixel of the pixelated scintillating transparent ceramics; Figure 3 Microscopic structure diagram of the pixelated scintillating transparent ceramics prepared in Example 1; where (a) is the front view and (b) is the side view; Figure 4 Radiation luminescence spectrum of the pixelated scintillating transparent ceramics prepared in Example 1 under X-ray excitation; Figure 5 Radiation luminescence spectrum of the rectangular block-shaped scintillating transparent ceramics prepared in Comparative Example 1 under X-ray excitation; Figure 6 Transmittance curve of the scintillating transparent ceramics prepared in Example 1 (thickness 1 mm); Figure 7 Photoluminescence spectrum of the pixelated scintillating transparent ceramics prepared in Example 2 under 365 nm excitation light. Detailed implementation manners

[0020] To further illustrate the invention content, features and actual effects of the present invention, the present invention will be described in detail below with reference to examples. It should be noted that the modified methods designed in the present invention are not limited to these specific implementation manners. Without departing from the spirit and connotation of the present invention design, equivalent replacements and modifications made by those skilled in the art on the basis of reading the content of the present invention are also within the scope claimed by the present invention.

[0021] In the present disclosure, a pixelated scintillating transparent ceramic is provided, which has characteristics of high spatial resolution and radiation detection sensitivity. The pixelated scintillating transparent ceramic includes scintillating transparent ceramic pixels arranged periodically on the same horizontal plane, forming a pixelated structure. By reducing the optical crosstalk of scintillation light, the light yield of the scintillating ceramic is improved, and its spatial resolution and radiation detection sensitivity are further enhanced. Among them, S is the cross-sectional area of the pixel, θ is the pixel cone angle, H is the height of the pixel, L is the distance between adjacent pixels, and S, θ, H, and L jointly determine the effective size of the scintillating transparent ceramic pixel. Specifically, in the present invention, the cross-sectional area S of each scintillating transparent ceramic pixel is 100 μm 2 ~0.25 mm 2 , preferably 250 μm 2 ~0.2 mm 2 , the cone angle θ is 0° to 15°, preferably 4° to 10°, the pixel height H is 500 to 2000 μm, preferably 800 to 1500 μm, and the shortest distance L between adjacent scintillating transparent ceramic pixels is 10 to 500 μm, preferably 20 to 250 μm. Controlling S, θ, H, and L within a suitable range in the present invention can effectively reduce the optical crosstalk phenomenon of scintillation light during propagation and improve the light yield. If the parameters are not within the suitable range, it will be difficult for the pixelated structure to be formed during the 3D printing process, which will have an adverse impact on the light yield of the pixelated scintillating transparent ceramic.

[0022] In the present invention, the pixelated scintillating transparent ceramic emits high-intensity scintillation light under the excitation of high-energy X-rays. When the scintillation light passes through the pixelated scintillating transparent ceramic pixels arranged in an array on the same plane, the scintillation light can be emitted along the pixel direction, thereby effectively reducing the optical crosstalk caused by lateral dispersion during light propagation.

[0023] In an alternative embodiment, the pixelated scintillating transparent ceramic is a rare earth doped transparent ceramic; the rare earth doped transparent ceramic can be Y3Al5O 12 :RE, Lu2O3:RE, Y2O3:RE, Lu3Al5O 12 :RE, Gd3Al2Ga3O 12 :RE, Lu2Y2SiO5:RE, Gd2O2S:RE, La2Hf2O7:RE, Y2Hf2O7:RE, Gd2Hf2O7:RE, YVO4:RE, etc.; among them, RE is Ce 3+ , Eu 2+ , Pr 3+ , Cr 3+ , Tb 3+ , Sm 3+ , Dy 3+ , Ho 3+ , Tm 3+One or more of the RE; the doping content of the RE may be 0.1 to 5 mol%.

[0024] In the present invention, 3D printing technology is used to integrally prepare pixelated scintillating transparent ceramic green bodies, which are then degreased, sintered, and polished to obtain pixelated scintillating transparent ceramics. The following exemplifies the preparation method of the pixelated scintillating transparent ceramics provided by the present invention.

[0025] Preparation of 3D printing scintillating ceramic slurry: Weigh the raw material powder of the desired scintillating transparent ceramic (ceramic powder) and an appropriate amount of photosensitive resin and mix them thoroughly to obtain scintillating ceramic slurry.

[0026] In an optional embodiment, the ceramic powder may be Y3Al5O 12 :RE、Lu2O3:RE、Y2O3:RE、Lu3Al5O 12 :RE, Gd3Al2Ga3O 12 :RE, Lu2Y2SiO5:RE, Gd2O2S:RE, La2Hf2O7:RE, Y2Hf2O7:RE, Gd2Hf2O7:RE, YVO4:RE; wherein RE is selected from Ce 3+ 、Eu 2+ 、Pr 3+ Cr 3+ 、Tb 3+ 、Sm 3+ 、Dy 3+ 、Ho 3+ and Tm 3+ At least one of. For example, Y3Al5O 12 :Ce,, Lu2O3:Tm, Y2O3:Dy, Lu3Al5O 12 :Pr, La2Hf2O7:Ce, YVO4:Ce, CaAlSiN3:Eu powder, etc., preferably YAG:Ce. Among them, the ceramic powder can account for 60-82wt% of the total mass of the ceramic powder and the photosensitive resin, preferably 74-79wt%.

[0027] In an alternative embodiment, the photosensitive resin comprises 70 - 85 wt% epoxy acrylate resin, 0.1 - 1 wt% photoinitiator, 12 - 25 wt% plasticizer, and 1 - 6 wt% dispersant, and the sum of the mass percentages of each component is 100 wt%. Among them, the photoinitiator may be at least one of 2,2 - diethoxyacetophenone, 4 - phenylbenzophenone, benzophenone chloride, and 2,4,6 - trimethylbenzoyl - diphenylphosphine oxide. The plasticizer may be at least one of polyethylene glycol, di(2 - ethylhexyl) phthalate, glycol benzoate, and tris(isodecyl) trimellitate. The dispersant may be at least one of triethylhexyl phosphate, sodium dodecyl sulfate, methyl amyl alcohol, and fatty acid polyethylene glycol ester. Among them, epoxy acrylate resin is the main component of the photosensitive resin. In order to obtain a green body with higher strength, it needs to account for a relatively high proportion in the photosensitive resin, and a ceramic green body with higher strength can be obtained; the photoinitiator can initiate the polymerization and cross - linking curing of the resin. In order to obtain a better photo - cured thickness, its content is controlled at a lower level; the plasticizer can provide binding force for the ceramic green body. In order to obtain a stronger binding force of the ceramic green body, its content needs to be maintained below that of the epoxy acrylate resin; the dispersant can evenly disperse the scintillating ceramic powder and improve the stability of the slurry. However, too high a content of the dispersant will make the slurry more likely to deposit and agglomerate, and its content needs to be controlled within a certain range.

[0028] Preparation of pixelated transparent scintillating transparent ceramic green body. Using 3D printing technology, according to the array structure parameters of the pixelated scintillating transparent ceramic pixels, a pixelated scintillating transparent ceramic model is designed by computer - aided design and imported into a 3D printer, and the scintillating ceramic slurry is printed layer by layer under light to obtain a pixelated scintillating transparent ceramic green body. Among them, the parameters of the 3D printing technology include: the single - layer thickness can be 0.03 - 0.05 mm; the light intensity can be 20 - 60 mW / cm 2 。

[0029] In an alternative embodiment, the array structure parameters of the pixelated scintillating transparent ceramic include: the cross - sectional area S of each scintillating transparent ceramic pixel is 100 μm 2 ~0.25 mm 2 ,the cone angle θ is 0° - 15°, the height H is 500 - 2000 μm; the distance L between adjacent scintillating transparent ceramic pixels is 10 - 500 μm; the configuration of the scintillating transparent ceramic pixel is columnar, frustum - shaped, or truncated - cone - shaped; the cross - sectional shape of the scintillating transparent ceramic pixel is square, regular hexagon, or circular. The shape of a single pixel and the distance between adjacent pixels can be adjusted adaptively according to S, θ, H, and L.

[0030] The pixelated scintillating transparent ceramic green body is subjected to debinding heat treatment to remove organic matter, obtaining a ceramic green body with strength.

[0031] In an alternative embodiment, the temperature of the degreasing heat treatment can be 800 - 1200 °C, the time can be 1 - 5 hours, and the heating rate can be 0.1 - 1 °C / min.

[0032] The green ceramic body is subjected to high-temperature sintering to obtain a dense pixelated scintillating transparent ceramic.

[0033] In an alternative embodiment, the high-temperature sintering can be vacuum sintering. The temperature of the vacuum sintering can be 1650 - 1950 °C, the holding time can be 1 - 20 hours, and the vacuum degree is not less than 10 -3 Pa.

[0034] The obtained pixelated scintillating transparent ceramic is annealed in an annealing furnace at 1300 - 1500 °C for 2 - 10 hours, aiming to eliminate internal stress and oxygen vacancy defects.

[0035] The annealed scintillating transparent ceramic is polished to obtain the pixelated scintillating transparent ceramic.

[0036] In the present disclosure, pixelated scintillating transparent ceramics with different structural parameters can be obtained by adjusting S, θ, H, and L. Moreover, when the obtained pixelated scintillating transparent ceramics are excited by the same X-rays, the maximum value of the excitation light is significantly increased compared with that of the bulk scintillating transparent ceramic, that is, the phenomenon of optical crosstalk is significantly reduced.

[0037] The following further exemplifies embodiments to illustrate the present invention in detail. It should be understood that the following embodiments are only used to further illustrate the present invention and cannot be construed as limiting the protection scope of the present invention. Those skilled in the art's non-essential improvements and adjustments based on the above content of the present invention all fall within the protection scope of the present invention. The specific process parameters and the like in the following examples are also only an example within a suitable range, that is, those skilled in the art can make selections within a suitable range through the description herein, rather than being limited to the specific values in the following examples.

[0038] Example 1

[0039] The preparation process of the pixelated scintillating transparent ceramic in this Example 1 includes: (1) Accurately weigh 200 g of Y3Al5O 12 :0.4 mol% Ce ceramic powder, add 66.74 g of photosensitive resin, and mix thoroughly using a planetary mill to obtain a ceramic slurry. The composition of the photosensitive resin includes 52.67 g of epoxy acrylate resin, 0.07 g of 2,2 - diethoxyacetophenone, 10 g of polyethylene glycol, and 4 g of triethylhexyl phosphate; (2) Design the structural parameters of the pixelated scintillating transparent ceramic array as follows: set the pixel structure to a truncated cone shape, the pixel arrangement to a square distribution, the diameter R of the cross-section circle to 500 μm, the cone angle θ to 4°, the height H to 800 μm, and the distance L between adjacent pixels to 100 μm, and then input them into the 3D printer program; (3) Pour the obtained ceramic slurry into the trough of a 3D printer and print pixelated shimmering transparent ceramic greenware according to the design parameters. The 3D printing parameters include: single layer thickness of 0.05 mm; light intensity of 60 mW / cm 2 ; (4) degreasing the obtained ceramic green body in a muffle furnace, specifically, heating to 950°C at a heating rate of 0.2°C / min and then holding the temperature for 2 hours to obtain a pixelated scintillating transparent ceramic green body; (5) vacuum sintering the pixelated scintillating transparent ceramic blank, the specific process includes: -3 Pa vacuum atmosphere, heated to 1760℃ and kept at this temperature for 6 hours. Then cooled in the furnace and annealed in an annealing furnace at 1400℃ for 6 hours to obtain Y3Al5O 12 :Ce pixelated scintillating transparent ceramic; (6) The obtained ceramic is polished to obtain Y3Al5O 12 :Ce pixelated shimmering transparent ceramic.

[0040] Example 2

[0041] The preparation process of the pixelated scintillating transparent ceramic in Example 2 is similar to that in Example 1, except that: in step (1), Lu3Al5O 12 : Ce is used as the scintillating transparent ceramic material (Ce doping amount is 0.4 mol%); in step (2), the structural parameters of the pixelated scintillating transparent ceramic array are designed as follows: the pixel structure is set to a truncated cone shape, the pixel arrangement is a regular hexagonal distribution, the diameter R of the cross-section circle is 500 μm, the cone angle θ is 10°, the height H is 1000 μm, and the distance L between adjacent pixels is 10 μm.

[0042] Comparative Example 1

[0043] The preparation process of the rectangular block-type scintillating transparent ceramic in this comparative example 1 includes: (1) Accurately weigh 200g Y3Al5O 12 0.4 mol% Ce ceramic powder was added to 66.74 g of photosensitive resin and thoroughly mixed using a planetary mill to obtain a ceramic slurry. The photosensitive resin contained 52.67 g of epoxy acrylate resin, 0.07 g of 2,2-diethoxyacetophenone, 10 g of polyethylene glycol, and 4 g of triethylhexyl phosphoric acid. (2) The structural parameters of the rectangular block-type scintillating transparent ceramic are designed as follows: the length, width and height of the rectangle are 14 mm, 16 mm and 4 mm respectively; (3) Pour the obtained ceramic slurry into the trough of the 3D printer and print the rectangular block ceramic green body according to the design parameters. The 3D printing parameters include: single layer thickness of 0.05mm; light intensity of 60mW / cm 2 ; (4) degreasing the obtained scintillating transparent ceramic green body in a muffle furnace, specifically, heating to 950° C. at a heating rate of 0.2° C. / min and then holding the temperature for 2 h to obtain a green body; (5) The ceramic blank is sintered in vacuum. The specific process includes: -3 Pa vacuum atmosphere, heated to 1760 ° C and kept at this temperature for 6 hours. Then, after cooling with the furnace, annealing treatment was carried out in an annealing furnace at 1400 ° C and kept at this temperature for 6 hours to obtain a block of scintillating transparent ceramics; (6) Polishing the block-shaped scintillating transparent ceramic to 0.3 mm to obtain the rectangular block-shaped scintillating transparent ceramic.

[0044] Figure 1 Schematic diagram of the structure of the pixelated scintillating transparent ceramic prepared in Example 1. Figure 2 This is a schematic diagram of the conversion of X-rays from a single pixel of a pixelated scintillating transparent ceramic into scintillation light. When X-rays are incident from the top or bottom of the ceramic pixel, the scintillating transparent ceramic emits scintillation light, which then propagates inside the pixel and exits in the direction of the pixel.

[0045] Figure 3 The microstructure of the pixelated scintillating transparent ceramic prepared in Example 1 (where (a) is a front view and (b) is a side view) is shown. The pixelated structure in Example 1 prepared under appropriate design parameters is neat and uniform, with no obvious problems.

[0046] Figure 4 This is the radioluminescence spectrum of the pixelated scintillating transparent ceramic prepared in Example 1 under X-ray excitation. Figure 5 This is the luminescence spectrum of the rectangular block scintillating transparent ceramic prepared in comparative example 1 under X-ray excitation. 12 : Ce scintillation properties. The luminescence spectrum of the pixelated scintillation transparent ceramic prepared in Example 1 under X-ray excitation shows a broad emission band between 500 and 750 nm, with a maximum luminescence intensity of approximately 2.3 × 10 5 Compared with the bulk scintillating transparent ceramic in comparative example 1, the maximum value of its emission band increases by about 1.2×10 5 , the optical crosstalk phenomenon is significantly improved.

[0047] The Y3Al5O prepared in Comparative Example 1 12 :0.4 mol% Ce ceramic was double-sided polished to a thickness of 1 mm, and its transmittance was measured. The results are as Figure 6 shown. Its transmittance at 538 nm is 81.9%. Since the only difference between Example 1 and Comparative Example 1 lies in the structure, the transmittance curve of the material in Comparative Example 1 is the same as that in Example 1. The high transmittance of the material itself provides a good environment for the propagation of scintillation light in the ceramic.

[0048] Figure 7 is the photoluminescence spectrum of the pixelated scintillating transparent ceramic prepared in Example 2 under 365 nm excitation light. As can be seen from the figure, the photoluminescence spectrum of the ceramic in Example 2 under 365 nm excitation light shows an emission band of 450 - 650 nm, and the luminescence intensity is the largest at 510 nm.

Claims

1. A pixelated scintillating transparent ceramic, characterized in that, The pixelated scintillating transparent ceramic is composed of a plurality of scintillating transparent ceramic pixels arranged periodically; the cross-sectional area S of each scintillating transparent ceramic pixel is 100 μm 2 to 0.25 mm 2 ; the cone angle θ is 0° to 15°; the height H is 500 to 2000 μm; the distance L between adjacent scintillating transparent ceramic pixels is 10 to 500 μm; the configuration of the scintillating transparent ceramic pixel is columnar, frustum-shaped, or truncated conical; the pixelated scintillating transparent ceramic is a rare-earth doped transparent ceramic, selected from Y3Al5O 12 :RE, Lu2O3:RE, Y2O3:RE, Lu3Al5O 12 :RE, Gd3Al2Ga3O 12 :RE, Lu2Y2SiO5:RE, Gd2O2S:RE, La2Hf2O7:RE, Y2Hf2O7:RE, Gd2Hf2O7:RE, YVO4:RE, at least one of them; where RE is selected from Ce 3+ , Eu 2+ , Pr 3+ , Cr 3+ , Tb 3+ , Sm 3+ , Dy 3+ , Ho 3+ and Tm 3+ at least one of them.

2. The pixelated scintillating transparent ceramic according to claim 1, wherein The doping amount of RE in the pixelated scintillating transparent ceramic is 0.1-5 mol %.

3. A method for preparing a pixelated scintillating transparent ceramic as described in claim 1 or 2, characterized in that, include: (1) mixing scintillating ceramic powder and photosensitive resin to obtain scintillating ceramic slurry; (2) Using 3D printing technology to prepare pixelated scintillating transparent ceramic green bodies; (3) degreasing and sintering the obtained pixelated scintillating transparent ceramic green body to obtain a pixelated scintillating transparent ceramic green body; (4) Polishing the pixelated scintillating transparent ceramic blank to obtain the pixelated scintillating transparent ceramic.

4. The preparation method according to claim 3, characterized in that, In step (1), the scintillating ceramic powder accounts for 60 to 82 wt %, preferably 74 to 79 wt %, of the total mass of the scintillating ceramic powder and the photosensitive resin.

5. The preparation method according to claim 3 or 4, characterized in that, In step (1), the scintillation ceramic powder is Y3Al5O 12 :RE, Lu2O3:RE, Y2O3:RE, Lu3Al5O 12 :RE, Gd3Al2Ga3O 12 :RE, Lu2Y2SiO5:RE, Gd2O2S:RE, La2Hf2O7:RE, Y2Hf2O7:RE, Gd2Hf2O7:RE, YVO4:RE, or at least one of them; where RE is selected from Ce 3+ , Eu 2+ , Pr 3+ , Cr 3 + , Tb 3+ , Sm 3+ , Dy 3+ , Ho 3+ and Tm 3+ or at least one of them.

6. The preparation method according to any one of claims 3-5, characterized in that, In step (1), the photosensitive resin comprises: 70-85 wt% epoxy acrylate resin, 0.1-1 wt% photoinitiator, 12-25 wt% plasticizer and 1-6 wt% dispersant, and the sum of the mass percentages of the components is 100 wt%; Preferably, the photoinitiator is at least one of 2,2-diethoxyacetophenone, 4-phenylbenzophenone, chlorinated benzophenone, and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide; Preferably, the plasticizer is at least one of polyethylene glycol, diethylhexyl phthalate, glycol benzoate, and triisodecyl trimellitate; Preferably, the dispersant is at least one of triethylhexyl phosphate, sodium lauryl sulfate, methylpentanol, and fatty acid polyethylene glycol ester.

7. The preparation method according to any one of claims 3-6, characterized in that, In step (2), the 3D printing technology includes: according to the array structure parameters of pixelated scintillating transparent ceramic pixels, using computer-aided design to design a pixelated scintillating transparent ceramic model and import it into a 3D printer, and layer-by-layer printing the scintillating ceramic slurry under light; preferably, the parameters of the 3D printing technology include: the single-layer thickness is 0.03 to 0.05 mm; the light intensity is 20 to 60 mW / cm 2 .

8. The preparation method according to any one of claims 3-7, characterized in that, In step (3), the degreasing temperature is 800-1200° C., the time is 1-5 hours, and the heating rate is 0.1-1° C. / min.

9. The preparation method according to any one of claims 3-8, characterized in that, In step (3), the sintering method is vacuum sintering; the temperature of the vacuum sintering is 1650-1950 °C, the time is 1-20 hours, and the vacuum degree is not less than 10 - 3 Pa.

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