Ultralow-afterglow fast-scintillation-attenuation rare earth orthosilicate scintillating material, preparation method and application

Abstract

The invention provides an ultra-low afterglow fast scintillation attenuation rare earth orthosilicate scintillation material, a preparation method and an application, the chemical formula of the scintillation material based on the raw material ratio is RE2 (1-u-v-w) Ce2uM2vH2v + yN2wSi1-yAlyO5, H represents a hydrogen element and is provided by a preparation atmosphere, 0 < u < = 0.05, 0 < = v < = 0.02, 0 < w < = 0.05, 0 < = y < = 0.02, v + y > 0, RE represents a rare earth element, the rare earth element is selected from at least one of lutetium, yttrium, gadolinium and lanthanum, and y is greater than 0. The strong oxygen vacancy trapping type doping element comprises an aluminum element and / or an M element, the M element is selected from at least one of magnesium, calcium and nickel elements, N represents a strong carrier bound type doping element, and the strong carrier bound type doping element is selected from at least one of ytterbium, praseodymium and holmium elements. According to the rare earth orthosilicate scintillating material, the afterglow intensity can be reduced to below 200ppm (lower than 200ppm and 10ms) within 10ms after continuous irradiation is terminated, and can be reduced to below 20ppm (lower than 20ppm and 20ms) within 20ms, and meanwhile, the attenuation time for attenuating the scintillating light intensity to 1 / e of the original intensity under the irradiation of ionizing radiation is less than or equal to 15ns.

Description

Technical Field

[0001] This invention relates to the field of scintillation materials technology, specifically to an ultra-low afterglow fast scintillation decay rare earth orthosilicate scintillation material, its preparation method, and its application. Background Technology

[0002] Inorganic scintillation materials are crystalline energy converters that can transform the energy of high-energy photons (X / γ rays) or particles (protons, neutrons, etc.) into easily detectable ultraviolet / visible photons. Detectors made from inorganic scintillation crystals are widely used in high-energy physics, nuclear physics, space physics, nuclear medicine diagnostics (XCT, PET, PCCT), geological exploration, and security inspection. With the rapid development of nuclear detection and related technologies, the performance requirements for inorganic scintillation crystals have also significantly increased. Currently, traditional scintillation crystals such as NaI(Tl), BGO, and PWO can no longer meet current requirements. The new generation of rare-earth orthosilicate scintillation crystals (chemical formula RE2SiO5, RE = Lu, Y, Gd, etc.), with their high light output, fast scintillation decay characteristics, and excellent radiation hardness, have become the core detection materials for high-end imaging equipment such as PET, high-energy physics detectors, and industrial CT. However, the persistent afterglow emission (usually referring to low-intensity emission >1 ms) that occurs after ionizing radiation excitation of this type of crystal causes "artifacts" in imaging, severely reducing the spatial resolution and quantitative accuracy of the image. Furthermore, strong persistent afterglow prolongs the detector's dead time, hindering the realization of high frame rate dynamic imaging in the imaging system. Therefore, deeply suppressing afterglow intensity has become a core technical challenge in improving imaging quality and detection accuracy in the field of radiation detection.

[0003] To address the afterglow problem, materials scientists have developed various strategies. The core idea is to manipulate the composition and microstructure of crystalline materials to alter their electronic band structure and defect states, thereby managing carrier trapping and recombination pathways. These methods are collectively known as "defect engineering" or "composition engineering." Among these, co-doping, which involves introducing one or more other ions into the crystal in addition to the main activator, has proven to be the most effective and widely studied approach for suppressing afterglow. Its goal is to obtain material compositions that are essentially free of or contain very few electron / hole traps that cause afterglow. Yang et al. (IEEE Trans. Nucl. Sci. 2009, 56 (5), 2960-2965. Figure 5) reported the co-doping effect of Ca in LSO:Ce, finding that the afterglow intensity of the undoped LSO:Ce crystal could only decrease to 1% (10000ppm) 1000s after X-ray irradiation was terminated, while when the Ca co-doping concentration was 0.4 at.%, the afterglow intensity could be reduced to 0.02% (200ppm) within about 200s. Masalov et al. (Tech. Phys. Lett. 2009, 35 (2), 154-157.) reported the co-doping effect of Yb in LSO:Ce, finding that Yb could also reduce the crystal afterglow to some extent. When the Yb co-doping concentration was 0.5 at.%, the afterglow of the LSO:Ce crystal could be reduced by an order of magnitude, but the afterglow was still relatively strong. Li et al. (LaserPhotonics Rev. 2025, e00767) reported the effect of multi-cation co-doping of Li, Ca, Yb, and Al on the afterglow of LYSO:Ce, finding that multi-cation co-doping of Li, Ca, Yb, and Al can significantly reduce the afterglow, optimally reducing the afterglow of LYSO:Ce crystals to 200 ppm after 40 ms. French patent FR2967420B1, US patent US9868900B2, and Chinese patent CN101001936A disclose a research scheme for reducing rare earth orthosilicates by co-doping with divalent alkali metals and trivalent elements, achieving an afterglow of less than 200 ppm after 100 ms following X-ray irradiation termination. The chemical formula is Ln. (2-z-x) Ce x M z Si (p-v) M ′ v O (3+2p) and Lu (2-y) Y (y-z-x) Ce x M z Si (p-v) M ′ vIn the low afterglow scintillator material of O5, Ln represents the main rare earth elements (Y, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) with a rare earth site ratio greater than or equal to 80%, M represents divalent alkaline earth metal ions (Ca, Mg, Sr), M' represents trivalent metal ions (Al, In, Ga), (z+v) is greater than or equal to 0.0001 and less than or equal to 0.2, z is greater than or equal to 0 and less than or equal to 0.2, v is greater than or equal to 0 and less than or equal to 0.2, x is greater than or equal to 0.0001 and less than 0.1, and p is equal to 1 or 2. Chinese patent CN103249805A discloses a chemical formula Ln (2-z-x1-x2) B 3+ x1 B 4 + x2 M z M ′ v Si (p-v) O (3+2p) This patent, based on French patent FR2967420B1, specifies the valence state of boron (Ce, Pr, Tb) by adding a limit on x1 (greater than or equal to 0.00005 and less than 0.1), x2 (greater than or equal to 0.00005 and less than 0.1), x2 / (x1+x2) (greater than or equal to 0.05 and less than 1), and x1+x2 (less than 0.1). This allows for an afterglow of less than 200 ppm after 100 ms following X-ray irradiation termination. However, with the increasing detection frame rate in irradiation detection, this level of afterglow suppression is gradually becoming insufficient to meet application requirements, necessitating the development of novel low-afterglow scintillator materials.

[0004] Regarding afterglow suppression in rare-earth orthosilicate scintillator materials, previous applicants have disclosed single-element co-doping schemes using Al (Cryst. GrowthDes. 2023, 23 (6), 4562 - 4570.) and Ni (Cryst. GrowthDes. 2024, 24 (17), 7166 -7172.). However, studies have found that these two elements mainly have a better suppression effect on long afterglow in the second range, but are insufficient for suppressing afterglow at faster speeds. Previous applicants disclosed the accelerating effect of low-valence elements Al, Mg, Ca, Ni and competing luminescent elements Yb, Eu, Pr, Nd on the scintillation decay time of rare-earth orthosilicate scintillator materials in Chinese patent publication CN118460210A, but did not conduct research on its effect on afterglow suppression. Furthermore, existing technologies include co-doping schemes using elements such as Ca (IEEE Trans. Nucl. Sci. 2009, 56 (5), 2960 - 2965.), Mg, Sr (FR2967420B1), Yb (Tech. Phys. Lett. 2009, 35 (2), 154 - 157.), and Li, Ca, Yb, Al (Laser Photonics Rev. 2025, e00767). However, these schemes struggle to address the inherent problem of low-valence cation doping tending to induce oxygen vacancies (e.g., substitution of rare-earth sites with low-valence ions such as Ca, Mg, and Sr, and substitution of Si sites with low-valence ions such as Al, In, and Ga). Therefore, even at the optimal level (Laser Photonics Rev. 2025, e00767), only an afterglow of less than 200 ppm after 40 ms can be achieved, which is still insufficient and cannot meet the demand for more efficient afterglow suppression in practical applications. While there has been some research on Eu and Ho elements, most studies have focused on their properties as fluorescent or optical storage materials, without paying attention to their effect on suppressing the afterglow intensity of rare earth orthosilicate scintillator materials. Summary of the Invention

[0005] In view of these limitations of the prior art, the applicant has introduced interstitial H into rare earth orthosilicate materials under the action of a strong electric field. +Ion elimination addresses the charge imbalance problem introduced by low-valence cation co-doping. By introducing optically inert defect suppression elements (at least one of Al and / or Mg, Ca, Ni) and strongly carrier-binding elements (at least one of Yb, Eu, Pr, Ho) to multi-element co-dope rare-earth orthosilicate scintillation materials, the afterglow intensity of rare-earth orthosilicate scintillation materials can be reduced to below 200 ppm within 10 ms after the termination of continuous irradiation (below 200 ppm@10 ms), and to below 20 ppm within 20 ms (below 20 ppm@20 ms). At the same time, the decay time of its scintillation intensity to 1 / e of the original intensity under ionizing radiation irradiation is less than or equal to 15 ns, effectively solving the shortcomings of existing technologies in afterglow suppression of rare-earth orthosilicate scintillation materials.

[0006] According to a first aspect of the present invention, an ultra-low afterglow fast scintillation decay rare earth orthosilicate scintillation material is provided. The ultra-low afterglow fast scintillation decay rare earth orthosilicate scintillation material is a scintillation material co-doped with hydrogen ions, a strong oxygen vacancy trapping dopant, and a strong carrier binding dopant. The chemical formula of the ultra-low afterglow fast scintillation decay rare earth orthosilicate scintillation material based on the raw material ratio is RE2(1-uvw)Ce2uM2vH2v+yN2wSi1-yAlyO5, where 0<u≤0.05, 0≤v≤0.02, 0<w≤0.05, 0≤y≤0.02, and v+y>0, where H represents hydrogen element, which is provided by the preparation atmosphere.

[0007] RE represents a rare earth element, which is selected from at least one of lutetium, yttrium, gadolinium, and lanthanum.

[0008] The strong oxygen vacancy trapping dopant element includes aluminum and / or M, wherein the M element is selected from at least one of magnesium, calcium, and nickel.

[0009] The N represents a strongly carrier-bound dopant element, which is selected from at least one of ytterbium, praseodymium, and holmium.

[0010] Furthermore, the strong oxygen vacancy trapping dopant element includes either aluminum or M, wherein aluminum at least partially occupies silicon lattice sites.

[0011] Furthermore, the rare earth element is yttrium, lutetium, or a solid solution of both lutetium and yttrium.

[0012] Furthermore, the rare earth element is a solid solution of lutetium and yttrium, wherein the molar ratio of lutetium to yttrium is (7~9):1.

[0013] Furthermore, 0.001≤u≤0.005, 0.001≤v≤0.02, 0.004≤w≤0.05.

[0014] Furthermore, 0.003≤y≤0.02.

[0015] Furthermore, the scintillation material can have its afterglow and scintillation attenuation performance optimized by air annealing. However, if the annealing temperature exceeds 1400°C, the afterglow and scintillation attenuation performance will deteriorate due to the escape of hydrogen ions.

[0016] According to a second aspect of the present invention, a method for preparing an ultra-low afterglow fast scintillation decay rare-earth orthosilicate scintillation material is provided, characterized in that the scintillation material is a scintillation ceramic, and the preparation method includes the following steps:

[0017] S1 Weigh the RE source compound, Ce source compound, strong oxygen vacancy trapping doped source compound, strong carrier binding doped source compound, and SiO2 respectively to make the chemical formula based on the raw material ratio RE 2(1-u-v-w) Ce 2u M 2v N 2w Si 1-y Al y O5, and mix all raw materials thoroughly to obtain a mixed powder;

[0018] S2 After pressing the mixed powder obtained in step S1 into shape, scintillation ceramic sintering is performed. The main component of the sintering atmosphere is nitrogen, which contains hydrogen or hydrogen-containing gas with a volume concentration of at least 50 ppm. Interstitial hydrogen ions are introduced by high-temperature negative bias hydrogen ion enrichment method. Specifically, during the sintering process, the ceramic is placed on the electrode and a negative bias is applied. The solid-phase reaction is carried out at a temperature of 1400~1600℃ for 10~50h to obtain the scintillation ceramic. The negative bias is -100V~-400V.

[0019] Furthermore, the strong oxygen vacancy trapping dopant source compound includes aluminum oxide and / or a compound containing element M, wherein the compound containing element M includes one or more of oxides, nitrides, silicates, and carbonates of element M; and the strong carrier binding dopant source compound includes one or more of oxides, nitrides, and carbonates of element N.

[0020] According to a second aspect of the present invention, a method for preparing an ultra-low afterglow fast scintillation decay rare-earth orthosilicate scintillation material is provided, for preparing the above-mentioned ultra-low afterglow fast scintillation decay rare-earth orthosilicate scintillation material, wherein the scintillation material is a scintillation crystal, and the preparation method includes the following steps:

[0021] S1 Weigh the RE source compound, Ce source compound, strong oxygen vacancy trapping doped source compound, strong carrier binding doped source compound, and SiO2 respectively to make the chemical formula based on the raw material ratio RE2(1-u-v-w) Ce 2u M 2v N 2w Si 1-y Al y O5, and mix all raw materials thoroughly to obtain a mixed powder;

[0022] S2 After pressing the mixed powder obtained in step S1 into shape, it is placed in a crucible and heated to 1900~2200℃ to melt and prepared by the Czochralski method. The main component of the preparation atmosphere is nitrogen, and it contains hydrogen or hydrogen-containing gas with a volume concentration of at least 50ppm. During the crystal preparation process, a negative bias voltage of -100V~-400V is applied at the crucible to introduce hydrogen ions into the melt and introduce hydrogen ions into the crystal during the crystal preparation process.

[0023] Furthermore, the strong oxygen vacancy trapping dopant source compound includes aluminum oxide and / or a compound containing element M, wherein the compound containing element M includes one or more of oxides, silicides, and carbonates of element M; and the strong carrier binding dopant source compound includes one or more of oxides, silicides, and carbonates of element N.

[0024] According to a third aspect of the present invention, the application of the ultra-low afterglow fast scintillation decay rare earth orthosilicate scintillation material of the first aspect described above is provided in any of the fields including high energy physics, nuclear physics, space physics, nuclear medicine imaging diagnostics, industrial non-destructive testing, security inspection, geology and mineral and oil well exploration, and environmental monitoring, and is particularly suitable for application in the field of single-photon CT (PCCT).

[0025] The above-described technical solution of the present invention has at least one of the following beneficial effects:

[0026] The ultra-low afterglow fast scintillation decay rare earth orthosilicate scintillation material of the present invention, by combining hydrogen ions, strong oxygen vacancy trapping dopants (aluminum and / or M, where M is selected from at least one of magnesium, calcium, and nickel) with strong carrier binding dopants (at least one of ytterbium, praseodymium, and holmium) to co-dope into the scintillation material, the afterglow intensity is greatly reduced.

[0027] In some embodiments, by optimizing the doping amounts of strong oxygen vacancy trapping dopants and strong carrier binding dopants, the hydrogen concentration in the protective atmosphere, the negative bias voltage of the material synthesis container / electrode (e.g., 0.001≤u≤0.005, 0.001≤v≤0.02, 0.004≤w≤0.05), the hydrogen volume concentration in the protective atmosphere (50~1000ppm), and the negative bias voltage of the container / electrode (-30~-180V), the afterglow intensity of the cerium-doped rare-earth orthosilicate scintillation material can be reduced to below 200ppm within 10ms after the termination of continuous irradiation (below 200ppm@10ms), and to below 20ppm within 20ms (below 20ppm@20ms). Simultaneously, the decay time for its scintillation intensity to decay to 1 / e of its original intensity under ionizing radiation irradiation is less than or equal to 15ns.

[0028] The ultra-low afterglow fast scintillation decay rare earth orthosilicate scintillation material of this application has the property of extremely short afterglow intensity, which can be well applied to any field including high energy physics, nuclear physics, space physics, nuclear medicine imaging diagnosis, industrial non-destructive testing, security inspection, geology and mineral and oil well exploration, and environmental monitoring, and is especially suitable for application in the field of single-photon CT (PCCT). Attached Figure Description

[0029] Figure 1 Showing undoped Lu 1.798 Y 0.2 Ce 0.002 SiO5 (LYSO:Ce), 0.4% Ca 2+ Co-doped Lu 1.790 Y 0.2 Ca 0.008 Ce 0.002 SiO5 (LYSO:Ce,0.4%Ca), 0.4%Ca 2+ with 2.0%Ho 3+ Co-doped Lu 1.774 Y 0.2 Ca 0.008 Ho 0.04 Ce 0.002 SiO5 (LYSO:Ce,0.4%Ca,2.0%Ho) and 0.4%Ca 2+ 2.0%Ho 3+ With 0.4%H + Co-doped Lu 1.75 Y 0.2 Ca 0.008 Ho 0.04 Ce 0.002 H 0.008X-ray diffraction pattern of SiO5 (LYSO:Ce,0.4%Ca,2.0%Ho,0.4%H) crystal. The inset in the pattern is a magnified view of the X-ray diffraction pattern within the 28-29.5° angle range.

[0030] Figure 2 The thermoluminescence spectra of LYSO:Ce (curve 1), LYSO:Ce,0.4%Ca (curve 2), LYSO:Ce,0.4%Ca,2.0%Ho (curve 3) and LYSO:Ce,0.4%Ca,2.0%Ho,0.4%H (curve 4) crystals are shown.

[0031] Figure 3 The scintillation decay spectra of LYSO:Ce (curve 1), LYSO:Ce,0.4%Ca (curve 2), LYSO:Ce,0.4%Ca,2.0%Ho (curve 3) and LYSO:Ce,0.4%Ca,2.0%Ho,0.4%H (curve 4) crystals are shown.

[0032] Figure 4 The afterglow intensity values ​​of LYSO:Ce,0.4%Ca,2.0%Ho,0.4%H crystals at 10ms are shown under different hydrogen concentrations and negative bias conditions. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention are within the scope of protection of the present invention.

[0034] The following describes the ultra-low afterglow fast scintillation decay rare earth orthosilicate scintillation material according to embodiments of this application.

[0035] The ultra-low afterglow fast scintillation decay rare-earth orthosilicate scintillation material according to the embodiments of this application is a scintillation material co-doped with hydrogen ion, strong oxygen vacancy trapping dopants, and strong carrier binding dopants. The chemical formula of the ultra-low afterglow fast scintillation decay rare-earth orthosilicate scintillation material based on the raw material ratio is RE. 2(1-u-v-w) Ce 2u M 2v H 2v+y N 2w Si 1-y Al yO5, where H represents hydrogen, provided by preparing an atmosphere of hydrogen or other hydrogen-containing gases, 0 < u ≤ 0.05, 0 ≤ v ≤ 0.02, 0 < w ≤ 0.05, 0 ≤ y ≤ 0.02, and v + y > 0; RE represents rare earth elements, selected from at least one of lutetium, yttrium, gadolinium, and lanthanum; strong oxygen vacancy trapping dopants include aluminum and / or M, selected from at least one of magnesium, calcium, and nickel; N represents strong carrier binding dopants, selected from at least one of ytterbium, praseodymium, and holmium.

[0036] The ultra-low afterglow, fast scintillation decay rare-earth orthosilicate scintillation material of this invention, through the co-doping of hydrogen ions, strong oxygen vacancy trapping dopants (aluminum and / or M, where M is selected from at least one of magnesium, calcium, and nickel), and strong carrier binding dopants (at least one of ytterbium, praseodymium, and holmium) into the scintillation material, significantly reduces the afterglow intensity and scintillation decay time to below 15 ns. Due to its ultra-low afterglow and fast scintillation decay characteristics, it can be better applied in high-energy physics, nuclear physics, space physics, nuclear medicine imaging diagnostics, industrial non-destructive testing, security inspection, geological and mineral exploration, oil well exploration, and environmental monitoring.

[0037] Furthermore, as a rare earth element, lutetium or yttrium, or a solid solution of both, is preferred; more preferably, a solid solution of both lutetium and yttrium, wherein the molar ratio of lutetium to yttrium is (7~9):1. By introducing Y, which is cheaper, has a lower melting point, and a larger ionic radius, into LSO:Ce crystals and combining it with lutetium-Lu in the above molar ratio to prepare a solid solution of LYSO:Ce, it is possible to reduce the melting point, reduce costs (raw materials, electricity costs for crystal preparation), reduce the defect level, and optimize the crystal performance.

[0038] Furthermore, the ultra-low afterglow fast scintillation decay rare earth orthosilicate scintillation material of this application contains at least a portion of interstitial hydrogen ions by adding a certain concentration of hydrogen in a protective atmosphere and applying a negative bias voltage to the material synthesis container / electrode.

[0039] Specifically, in the preparation of rare earth orthosilicate scintillation materials, Ca... 2+ Ho 3+ Taking co-doping with hydrogen ions as an example, Figure 1 Undoped Lu is shown 1.798 Y 0.2 Ce 0.002 SiO5 (LYSO:Ce), 0.4% Ca 2+ Co-doped Lu 1.790 Y 0.2 Ca 0.008 Ce0.002 SiO5 (LYSO:Ce,0.4%Ca), 0.4%Ca 2+ with 2.0%Ho 3+ Co-doped Lu 1.774 Y 0.2 Ca 0.008 Ho 0.04 Ce 0.002 SiO5 (LYSO:Ce,0.4%Ca,2.0%Ho) and 0.4%Ca 2+ 2.0%Ho 3+ With 0.4%H + Co-doped Lu 1.75 Y 0.2 Ca 0.008 Ho 0.04 Ce 0.002 H 0.008 X-ray diffraction patterns of SiO5 (LYSO:Ce,0.4%Ca,2.0%Ho,0.4%H) crystals. LYSO:Ce, LYSO:Ce,0.4%Ca, and LYSO:Ce,0.4%Ca,2.0%Ho crystals were prepared under an inert neutral atmosphere (nitrogen) with no voltage load on the crystal preparation container. LYSO:Ce,0.4%Ca,2.0%Ho,0.4%H was prepared under a protective atmosphere of 50 ppm hydrogen and with a negative bias voltage of -100V to -400V on the crystal preparation container. Figure 1 It can be seen that all the diffraction peaks recorded in the figure can pass through (Lu 1.81 Y 0.19 The SiO5 structure was indexed (PDF#97-002-8021), and no impurity peaks were found. Furthermore, compared to LYSO:Ce materials, 0.4% Ca... 2+ The X-ray diffraction peaks of the doped crystal gas shift to lower angles, indicating that doping increases the unit cell volume. This is mainly attributed to Ca. 2+ Radius (100 pm) is greater than Lu 3+ The ionic radius (86.1 pm) is large, Ca 2+ Replace Lu 3+ This leads to an increase in the interplanar spacing of the crystal, which in turn causes its X-ray diffraction peaks to shift to lower angles. Figure 1 As shown, compared to LYSO:Ce,0.4%Ca crystal, further co-doping with 2.0% Ho... 3+ The diffraction peaks of the LYSO:Ce,0.4%Ca,2.0%Ho crystals after ionization show a small-angle shift, which is mainly attributed to Ho. 3+ The ionic radius (90.1 pm) is greater than that of Lu. 3+ The ionic radius (86.1 pm) is slightly larger, Ho3+ Ion-substituted Lu 3+ The addition of ions resulted in a slight increase in the interplanar spacing.

[0040] It is worth noting that, without changing the type and concentration of co-doped ions, changing the protective atmosphere for crystal preparation to a protective gas containing 50 ppm hydrogen, and performing crystal preparation with a negative bias voltage of -100V to -400V on the crystal preparation container, the resulting LYSO:Ce,0.4%Ca,2.0%Ho,0.4%H crystal exhibits a further shift in X-ray diffraction peaks towards a smaller angle compared to the LYSO:Ce,0.4%Ca,2.0%Ho crystal. Figure 1 As shown in the inset, this can be attributed to the fact that hydrogen molecules are more easily thermally decomposed under low hydrogen partial pressure conditions (for example, when the total pressure of the protective gas is about 0.2 MPa, if the hydrogen concentration in the protective atmosphere is 50 ppm to 5000 ppm, the thermal decomposition temperature of hydrogen molecules is about 1000 to 1300 °C, and the lower the hydrogen partial pressure, the lower the decomposition temperature). During crystal preparation, the surface temperature of the melt can reach as high as 1900 to 2200 °C, while the hydrogen concentration in the protective gas is only 50 ppm. Therefore, after hydrogen molecules come into contact with the surface of the melt, they decompose rapidly and react with oxides in the melt to form hydrogen ions. Under the action of a negative bias electric field, the hydrogen ions are incorporated into the melt of the crystal raw material, and finally interstitial hydrogen ions are formed during the crystal preparation process. This leads to an increase in the interplanar spacing of the crystal, causing the X-ray diffraction peaks of the LYSO:Ce,0.4%Ca,2.0%Ho,0.4%H crystal to shift to a lower angle. Similar interstitial hydrogen ion formation also frequently occurs in metal smelting. For example, high-strength aluminum alloys used in aerospace and other fields are plagued by the problem of "hydrogen embrittlement" caused by the infiltration of hydrogen ions / atoms.

[0041] Furthermore, the ultra-low afterglow fast scintillation decay rare earth orthosilicate scintillation material of this application plays an important role in ultra-low afterglow by adding a certain concentration of hydrogen in a protective atmosphere and applying a negative bias voltage to the material synthesis container / electrode.

[0042] Specifically, in the preparation of rare earth orthosilicate scintillation materials, Ca... 2+ Ho 3+ Taking co-doping with hydrogen ions as an example, thermoluminescence spectroscopy is an important data source for characterizing the afterglow intensity of a crystal. Figure 2 Curves 1-4 show the thermoluminescence spectra of LYSO:Ce, LYSO:Ce,0.4%Ca, LYSO:Ce,0.4%Ca,2.0%Ho, and LYSO:Ce,0.4%Ca,2.0%Ho,0.4%H crystals. The defects corresponding to the thermoluminescence peak near 360K in the thermoluminescence spectra are significantly correlated with the crystal afterglow intensity, and these defects are generally considered to be caused by oxygen vacancies. Figure 2It can be seen that, compared to LYSO:Ce crystal, 0.4% Ca 2+ The thermoluminescence peak intensity of co-doped LYSO:Ce,0.4%Ca crystal can be reduced by about three orders of magnitude, which is consistent with the results reported by Yang et al. (IEEE Trans. Nucl. Sci. 2009, 56 (5), 2960-2965. Figure 7) and the thermoluminescence data shown in French patent FR2967420B1, US patent US9868900B2 and Chinese patent CN101001936A. Figure 2 As shown, while in 0.4% Ca 2+ Based on co-doping, 2.0% of the strongly carrier-bound dopant element Ho was further introduced. 3+ Subsequently, highly stable complex structures (corresponding to thermoluminescence peak temperatures above 480 K) will form in defects such as oxygen vacancies in the crystal, further reducing the thermoluminescence peak intensity by an order of magnitude, thus decreasing the crystal afterglow. Despite this, it is still difficult to completely eliminate the negative effect of low-valence element co-doping inducing oxygen vacancies in the crystal under the driving force of charge balance. However, by further introducing hydrogen ions into the crystal, the negative effect of charge imbalance caused by low-valence element co-doping can be effectively resolved. For example... Figure 2 As shown in curve 4, compared to the other three crystals, the thermoluminescence peak of the LYSO:Ce,0.4%Ca,2.0%Ho,0.4%H crystal is almost completely suppressed, indicating that this crystal has extremely low afterglow intensity. Compared to the previous patent CN118460210A, this invention can further reduce the afterglow by an order of magnitude.

[0043] Furthermore, the ultra-low afterglow fast scintillation decay rare earth orthosilicate scintillation material of this application, by adding a certain concentration of hydrogen in a protective atmosphere and applying a negative bias voltage to the material synthesis container / electrode, the interstitial hydrogen ions formed in the rare earth orthosilicate scintillation material play an important role in the fast scintillation decay time of the crystal.

[0044] Specifically, in the preparation of rare earth orthosilicate scintillation materials, Ca... 2+ Ho 3+ Taking co-doping with hydrogen ions as an example, thermoluminescence spectroscopy is an important data source for characterizing the afterglow intensity of a crystal. Figure 3 Curves 1-4 show the scintillation decay spectra of LYSO:Ce, LYSO:Ce,0.4%Ca, LYSO:Ce,0.4%Ca,2.0%Ho, and LYSO:Ce,0.4%Ca,2.0%Ho,0.4%H crystals. Figure 3 The LYSO:Ce,0.4%Ca,2.0%Ho,0.4%H concentration shown is attenuated to 1 / e when the scintillation intensity ( Figure 3(At the location indicated by the dashed line) a scintillation decay time of only 3.9 ns, which is faster than the other three crystals. This is mainly attributed to the fact that interstitial hydrogen ions can, to some extent, act as a medium for carrier transport, reducing the binding of carriers by potential level traps in the crystal, thereby accelerating the scintillation decay time. Figure 2 As shown, the introduction of hydrogen ions significantly suppressed shallow energy level traps in the 80-200K range of the crystal.

[0045] The following describes the ultra-low afterglow fast scintillation decay rare earth orthosilicate scintillation material and its preparation method in further detail with reference to specific embodiments.

[0046] The present invention provides an ultra-low afterglow fast scintillation decay rare earth orthosilicate scintillation material (chemical formula: RE). 2(1-u-v-w) Ce 2u M 2v H 2v+y N 2w Si 1-y Al y O5) Depending on the different preparation processes, it is mostly crystalline or ceramic, specifically:

[0047] Crystal preparation process: The raw materials for crystal preparation are weighed and mixed thoroughly to obtain a mixed powder. The mixture is then pressed into a block under cold isostatic pressure of 150-600 MPa. Subsequently, it is placed in an iridium crucible and heated to 1900-2200℃ by induction heating to fully melt it. A protective gas with nitrogen as the main component and hydrogen with a volume concentration of at least 50ppm is introduced into the crystal preparation furnace. At the same time, a negative bias voltage of -100V to -400V is applied to the crucible to introduce hydrogen ions into the melt. After seeding, crystals of the predetermined size are slowly pulled from the melt to prepare crystals.

[0048] Scintillation ceramic preparation process: The raw materials for crystal preparation are weighed and mixed thoroughly to obtain a mixed powder. The powder is then pressed into blocks under cold isostatic pressing at 150-600 MPa. The pressed mixture is then placed in a tube furnace or other sintering furnace with atmosphere conditioning. The sample is placed on a negative bias electrode material with a voltage of -100V to -400V, and a protective gas consisting mainly of nitrogen and containing hydrogen with a volume concentration of at least 50ppm is introduced. The mixture is then calcined at 1600 °C for at least 10 hours to undergo a solid-phase reaction, thereby obtaining scintillation ceramic.

[0049] It should be noted that in the following embodiments, the concentrations of Ce, M, and N dopants are the ratio of the number of Ce, M, and N atoms to the total number of rare earth lattice sites in the chemical formula of the ingredients, calculated as follows:

[0050] The chemical formula is RE 2(1-u-v-w) Ce 2u M 2vH 2v+y N 2w Si 1-y Al y The Ce doping concentration in O5 rare earth orthosilicate materials is C Ce =2u / [2(1-uvw)+ 2u+2v+2w]×100 at.%=100u at.%; Similarly, the doping concentration C of M M =2v / [2(1-uvw)+2u+2v+2w] ×100 at.%=100v at.%; Similarly, the doping concentration of N, C N =2w / [2(1-uvw)+ 2u+2v+2w] ×100 at.%=100w at.%.

[0051] Furthermore, in the embodiments, the concentration of Al dopant was designed according to its occupation of silicon lattice sites. Therefore, the Al doping concentration is the ratio of the number of Al atoms to the total number of atoms occupying silicon lattice sites in the chemical formula of the dopant, calculated as follows:

[0052] The chemical formula is RE 2(1-u-v-w) Ce 2u M 2v H 2v+y N 2w Si 1-y Al y The Al doping concentration C in O5 rare earth orthosilicate materials Al =y / [(1-y)+ y]×100 at.%=100y at.%.

[0053] Furthermore, in the embodiments, the H dopant is provided by the crystal preparation protective atmosphere, and its doping concentration is mainly affected by the concentration of low-valence co-doping of M and Al, the hydrogen concentration in the protective gas, and the magnitude of the negative bias voltage of the material preparation container / electrode. When the protective gas contains at least 50 ppm of hydrogen or a high-hydrogen-content gas, and the negative bias voltage applied to the preparation container / electrode is between -100V and -400V, the effects of hydrogen concentration and voltage changes on the doping effect are relatively small. Figure 4 As shown. Therefore, the doping concentration of H ions in the crystal is significantly related to the concentrations of M and Al elements in the feed. Therefore, in this paper, the H ion concentration is uniformly denoted as the sum of the M and Al element doping concentrations, calculated as follows:

[0054] The chemical formula is RE 2(1-u-v-w) Ce 2u M 2v H 2v+y N 2w Si 1-y Al y The H doping concentration C in O5 rare earth orthosilicate materials H =CM +C Al =2v / [2(1-uvw)+2u+2v+2w]×100 at.%+y / [(1-y)+y]×100 at.%=100(v+y)at.%.

[0055] Example 1 (Preparation of Ca, Yb, H co-doped LYSO:Ce scintillation material)

[0056] Crystal: Molar ratio of Lu₂O₃ : Y₂O₃ : CeO₂ : CaO : Yb₂O₃ : SiO₂ = (0.899-vw): 0.1 : 0.002 : 2v : w : 1 (v takes values ​​of 0.001, 0.002, 0.003, 0.004, 0.004, and 0.01 respectively; w takes values ​​of 0.002, 0.004, 0.006, 0.02, 0.05, and 0.05 respectively) is prepared by mixing thoroughly. The mixture is then pressed into a block under cold isostatic pressure at 250 MPa, placed in an iridium crucible, and a negative bias voltage of -100V to -400V is applied to the crucible. A protective gas consisting mainly of nitrogen and containing at least 50 ppm of hydrogen is introduced into a crystal preparation furnace. The mixture is induction heated to 1900-2200℃ and fully melted. After seeding, crystals of the predetermined size are slowly pulled from the melt to obtain Lu. 2(0.899-v-w) Y 0.2 Ce 0.002 Ca 2v H 2v Yb 2w SiO5 crystals.

[0057] Table 1 shows the afterglow intensity of Ca, Yb, and H co-doped LYSO:Ce crystals with different doping concentrations, and the scintillation decay time when the scintillation light decays to 1 / e of the maximum intensity after radiative excitation (I=I0 / e). (When the H ion doping concentration in the table is 0, it means that no voltage was applied to the crucible / electrode during the preparation of the scintillation material, and the preparation atmosphere was pure nitrogen.)

[0058] Table 1

[0059] Ca / at.% Yb / at.% H / at.% Afterglow intensity / ppm@10ms Afterglow intensity / ppm@20ms <![CDATA[Fluorescence decay time (I = I0 / e) / ns]]> Comparative Example 1-1 0 0 0 <![CDATA[1.6×10 4 ]]> <![CDATA[1.6×10 4 ]]> 41.5 Comparative Examples 1-2 0.1 0.2 0 1433 634 22.7 Example 1-1 0.1 0.2 0.1 190 20 13.5 Examples 1-2 0.2 0.4 0.2 98 17 10.0 Examples 1-3 0.3 0.6 0.3 90 14 5.8 Examples 1-4 0.4 2.0 0.4 78 14 4.1 Examples 1-5 0.4 5.0 0.4 64 14 2.5 Examples 1-6 1.0 5.0 1.0 58 13 2.0

[0060] Test methods: Afterglow intensity was determined by irradiating the scintillation material with pulsed X-rays (Golden XRS-4) with a pulse width of 500 ns. The crystal light signal was collected using a photomultiplier tube (Hamamatsu R2059 PMT), and the afterglow spectrum of the sample after X-ray irradiation was recorded using an oscilloscope (LeCroy8104). 100 afterglow spectra were recorded for each sample, and the background noise signal of the test system in the spectrum was subtracted. The average value was calculated after normalization to obtain the crystal afterglow intensity. Scintillation decay time was determined by using pulsed X-rays as the excitation source (Hamamatsu N16432) and recording the scintillation decay curve using a single-photon counter (Hamamatsu picoX 5084). The time required for the pulse intensity of the pulse spectrum to decay from the maximum value I0 to I0 / e was statistically analyzed to obtain the scintillation decay time of the crystal.

[0061] Table 1 shows the results of undoped LYSO:Ce crystal (Comparative Example 1-1), LYSO:Ce, 0.1%Ca, 0.2%Yb crystal (Comparative Example 1-2), LYSO:Ce, 0.1%Ca, 0.1%H, 0.2%Yb crystal (Example 1-1), LYSO:Ce, 0.2%Ca, 0.2%H, 0.4%Yb crystal (Example 1-2), and LYSO:Ce, 0.3%Ca, 0.3%H... The afterglow intensity and decay time of the scintillation pulse intensity when it decays to I=I0 / e were measured for 0.6%Yb crystals (Examples 1-3), LYSO:Ce,0.4%Ca,0.4%H,2.0%Yb crystals (Examples 1-4), LYSO:Ce,0.4%Ca,0.4%H,5.0%Yb crystals (Examples 1-5), and LYSO:Ce,1%Ca,1%H,5.0%Yb crystals (Examples 1-6). For Examples 1-6, the data for crystals with a Ca doping concentration of 1.0 at% were measured from solidified blocks cooled in an iridium crucible. This is because in the experiment, when the Ca doping concentration was too high, the surface tension of the melt decreased significantly, preventing successful crystal growth. Even if crystals were to grow accidentally, the significant difference between the radii of Ca and Lu / Y ions would cause the crystals to twist, crack, and contain numerous inclusions, rendering them practically useless.

[0062] As shown in Table 1, although the afterglow intensity and scintillation decay time of the crystal can be further improved by Ca and Yb co-doping compared to LYSO:Ce, they are still significantly insufficient. The afterglow intensity is still above 1000 ppm at 10 ms, and the scintillation decay time is also above 15 ns. However, after introducing interstitial hydrogen ions into the crystal through high-temperature negative bias hydrogen ion enrichment, the afterglow intensity is significantly reduced, decreasing to below 200 ppm within 10 ms (below 200 ppm@10 ms) and below 20 ppm within 20 ms (below 20 ppm@20 ms). At the same time, the scintillation decay time is reduced to 15 ns or less, and with the increase of Ca and Yb doping, the afterglow intensity and scintillation decay time are further improved.

[0063] Example 2 (Preparation of Ca, Ho, H co-doped LYSO:Ce scintillation material)

[0064] Crystal: Molar ratio of Lu₂O₃ : Y₂O₃ : CeO₂ : CaO : Ho₂O₃ : SiO₂ = (0.899-vw): 0.1 : 0.002 : 2v : w : 1 (As shown in Table 2, v takes values ​​of 0.001, 0.002, 0.003, 0.004, and 0.004 respectively; w takes values ​​of 0.002, 0.004, 0.006, 0.02, and 0.05 respectively) The ingredients are prepared and thoroughly mixed. The mixture is then pressed into a block under cold isostatic pressure at 250 MPa, placed in an iridium crucible, and a negative bias voltage of -100V to -400V is applied to the crucible. A protective gas consisting mainly of nitrogen and containing at least 50 ppm of hydrogen is introduced into the crystal preparation furnace. The mixture is induction heated to 1900~2200℃ and fully melted. After seeding, crystals of the predetermined size are slowly pulled from the melt to obtain Lu. 2(0.899-v-w) Y 0.2 Ce 0.002 Ca 2v H 2v Ho 2w SiO5 crystals.

[0065] Table 2 shows the afterglow intensity of Ca, Ho, and H co-doped LYSO:Ce crystals with different doping concentrations, and the scintillation decay time when the scintillation light decays to 1 / e of the maximum intensity after radiative excitation (I=I0 / e). (When the H ion doping concentration in the table is 0, it means that no voltage was applied to the crucible / electrode during the preparation of the scintillation material, and the preparation atmosphere was pure nitrogen.)

[0066] Table 2

[0067] Ca / at.% Ho / at.% H / at.% Afterglow intensity / ppm@10ms Afterglow intensity / ppm@20ms Scintillation decay time (I=I0 / e) / ns Comparative Example 2-1 0.1 0.2 0 1276 408 21.3 Example 2-1 0.1 0.2 0.1 198 20 13.4 Example 2-2 0.2 0.4 0.2 141 18 10.6 Example 2-3 0.3 0.6 0.3 108 16 7.0 Examples 2-4 0.4 2.0 0.4 103 15 3.9 Examples 2-5 0.4 5.0 0.4 97 12 2.3

[0068] Example 3 (Preparation of Ca, Pr, H co-doped LYSO:Ce scintillation material)

[0069] Scintillation ceramics: molar ratio of Lu₂O₃ : Y₂O₃ : CeO₂ : CaCO₃ : Pr₆O 11 The following formula was used: SiO2 = (0.899-vw) : 0.1 : 0.002 : 2v : w / 3 : 1 (v takes values ​​of 0.001, 0.002, 0.003, 0.004, and 0.004 respectively; w takes values ​​of 0.002, 0.004, 0.006, 0.02, and 0.05 respectively). After thorough mixing, the mixture was pressed into blocks under cold isostatic pressing at 250 MPa. The pressed mixture was then placed in a tube furnace, and the sample was placed on a negative bias electrode material with a voltage of -100V to -400V. A protective gas consisting mainly of nitrogen and containing hydrogen with a volume concentration of at least 50 ppm was introduced. The mixture was calcined at 1600 °C for 10 h to undergo a solid-state reaction, yielding Lu. 2(0.899-v-w) Y 0.2 Ce 0.002 Ca 2v H 2v Pr 2w SiO5 scintillation ceramics.

[0070] Table 3 shows the afterglow intensity of Ca, Pr, and H co-doped LYSO:Ce ceramics with different doping concentrations, and the scintillation decay time when the scintillation light decays to 1 / e of the maximum intensity after radiative excitation (I=I0 / e). (When the H ion doping concentration in the table is 0, it means that no voltage was applied to the crucible / electrode during the preparation of the scintillation material, and the preparation atmosphere was pure nitrogen.)

[0071] Table 3

[0072] Ca / at.% Pr / at.% H / at.% Afterglow intensity / ppm@10ms Afterglow intensity / ppm@20ms Scintillation decay time (I=I0 / e) / ns Comparative Example 3-1 0.1 0.2 0 1382 433 28.5 Example 3-1 0.1 0.2 0.1 195 20 14.7 Example 3-2 0.2 0.4 0.2 138 15 11.5 Example 3-3 0.3 0.6 0.3 130 15 6.1 Examples 3-4 0.4 2.0 0.4 99 15 4.1 Examples 3-5 0.4 5.0 0.4 98 13 2.2

[0073] Example 4 (Preparation of Mg, Yb, H co-doped LYSO:Ce scintillation material)

[0074] Crystals: Prepare the following mixture by mass ratio: Lu₂O₃ : Y₂O₃ : CeO₂ : Mg₃N₂ : Yb₂O₃ : SiO₂ = (0.899-vw) : 0.1 : 0.002 : 2v / 3 : w : 1 (v values ​​are 0.001, 0.002, 0.003, 0.004, 0.004; w values ​​are 0.002, 0.004, 0.006, 0.02, 0.05). Mix thoroughly and then heat the mixture at 250°C. The sample was pressed into a block under cold isostatic pressing at MPa, placed in an iridium crucible, and a negative bias voltage of -100V to -400V was applied to the crucible. A protective gas consisting mainly of nitrogen and containing at least 50ppm hydrogen was introduced into a crystal preparation furnace. The sample was induction heated to 1900~2200℃ and fully melted. After seeding, a crystal of the predetermined size was slowly pulled from the melt to obtain Lu. 2(0.899-v-w) Y 0.2 Ce 0.002 Mg 2v H 2v Yb 2w SiO5 crystals.

[0075] Table 4 shows the afterglow intensity of Mg, Yb, and H co-doped LYSO:Ce crystals with different doping concentrations, and the scintillation decay time when the scintillation light decays to 1 / e of the maximum intensity after radiative excitation (I=I0 / e). (When the H ion doping concentration in the table is 0, it means that no voltage was applied to the crucible / electrode during the preparation of the scintillation material, and the preparation atmosphere was pure nitrogen.)

[0076] Table 4

[0077] Mg / at.% Yb / at.% H / at.% Afterglow intensity / ppm@10ms Afterglow intensity / ppm@20ms Scintillation decay time (I=I0 / e) / ns Comparative Example 5-1 0.1 0.2 0 1491 694 22.1 Example 4-1 0.1 0.2 0.1 196 19 15.0 Example 4-2 0.2 0.4 0.2 146 15 10.6 Example 4-3 0.3 0.6 0.3 126 15 6.2 Example 4-4 0.4 2.0 0.4 104 13 3.8 Examples 4-5 0.4 5.0 0.4 98 13 2.5

[0078] Example 5 (Preparation of Mg, Ho, H co-doped LYSO:Ce scintillation material)

[0079] Scintillation ceramics: Lu₂O₃ : Y₂O₃ : CeO₂ : MgC₂ : Ho₂O₃ : SiO₂ = (0.899-vw) : 0.1 : 0.002 : 2v : w : 1 (v values ​​are 0.001, 0.002, 0.003, 0.004, 0.004; w values ​​are 0.002, 0.004, 0.006, 0.02, 0.05 respectively). After thorough mixing, the mixture was pressed into blocks under cold isostatic pressing at 250 MPa. The pressed mixture was then placed in a tube furnace, and the sample was placed on a negative bias electrode material with a voltage of -100V to -400V. A protective gas consisting mainly of nitrogen and containing at least 50 ppm hydrogen was introduced. The mixture was calcined at 1600 °C for 10 h to undergo a solid-phase reaction, yielding Lu₂O₃.2(0.899-v-w) Y 0.2 Ce 0.002 Mg 2v H 2v Ho 2w SiO5 scintillation ceramics.

[0080] Table 5 shows the afterglow intensity of LYSO:Ce ceramics with different doping concentrations of Mg, Ho, and H, as well as the scintillation decay time when the scintillation light decays to 1 / e of the maximum intensity after radiative excitation (I=I0 / e). (When the H ion doping concentration in the table is 0, it means that no voltage was applied to the crucible / electrode during the preparation of the scintillation material, and the preparation atmosphere was pure nitrogen.)

[0081] Table 5

[0082] Mg / at.% Ho / at.% H / at.% Afterglow intensity / ppm@10ms Afterglow intensity / ppm@20ms Scintillation decay time (I=I0 / e) / ns Comparative Example 5-1 0.1 0.2 0 1373 435 22.3 Example 5-1 0.1 0.2 0.1 179 20 15.0 Example 5-2 0.2 0.4 0.2 130 18 8.5 Example 5-3 0.3 0.6 0.3 115 16 5.9 Example 5-4 0.4 2.0 0.4 103 13 3.5 Example 5-5 0.4 5.0 0.4 95 13 2.3

[0083] Example 6 (Preparation of Mg, Pr, H co-doped LYSO:Ce scintillation material)

[0084] Crystals: Prepare the mixture by mass ratio of Lu₂O₃ : Y₂O₃ : CeO₂ : MgO : Pr₂(CO₃)₃ : SiO₂ = (0.899-vw) : 0.1 : 0.002 : 2v : w : 1 (v takes values ​​of 0.001, 0.002, 0.003, 0.004, 0.004; w takes values ​​of 0.002, 0.004, 0.006, 0.02, 0.05). After thorough mixing, heat the mixture at 250°C. The sample was pressed into a block under cold isostatic pressing at MPa, placed in an iridium crucible, and a negative bias voltage of -100V to -400V was applied to the crucible. A protective gas consisting mainly of nitrogen and containing at least 50ppm hydrogen was introduced into a crystal preparation furnace. The sample was induction heated to 1900~2200℃ and fully melted. After seeding, a crystal of the predetermined size was slowly pulled from the melt to obtain Lu. 2(0.899-v-w) Y 0.2 Ce 0.002 Mg 2v H 2v Pr 2w SiO5 crystals.

[0085] Table 6 shows the afterglow intensity of Mg, Pr, and H co-doped LYSO:Ce crystals with different doping concentrations, and the scintillation decay time when the scintillation light decays to 1 / e of the maximum intensity after radiative excitation (I=I0 / e). (When the H ion doping concentration in the table is 0, it means that no voltage was applied to the crucible / electrode during the preparation of the scintillation material, and the preparation atmosphere was pure nitrogen.)

[0086] Table 6

[0087] Mg / at.% Pr / at.% H / at.% Afterglow intensity / ppm@10ms Afterglow intensity / ppm@20ms Scintillation decay time (I=I0 / e) / ns Comparative Example 6-1 0.1 0.2 0 1412 427 28.8 Example 6-1 0.1 0.2 0.1 186 20 13.3 Example 6-2 0.2 0.4 0.2 158 18 9.6 Example 6-3 0.3 0.6 0.3 134 16 5.3 Example 6-4 0.4 2.0 0.4 123 14 3.6 Example 6-5 0.4 5.0 0.4 110 12 2.6

[0088] Example 7 (Preparation of Ni, Yb, H co-doped LYSO:Ce scintillation material)

[0089] Crystals: Prepare the following formula by mass ratio: Lu₂O₃ : Y₂O₃ : CeO₂ : NiO : Yb₂O₃ : SiO₂ = (0.899-vw : 0.1 : 0.002 : 2v : w : 1 (v values ​​are 0.001, 0.003, 0.006, 0.01, 0.02; w values ​​are 0.002, 0.004, 0.006, 0.02, 0.05). Mix thoroughly and then heat the mixture at 250°C. The sample was pressed into a block under cold isostatic pressing at MPa, placed in an iridium crucible, and a negative bias voltage of -100V to -400V was applied to the crucible. A protective gas consisting mainly of nitrogen and containing at least 50ppm hydrogen was introduced into a crystal preparation furnace. The sample was induction heated to 1900~2200℃ and fully melted. After seeding, a crystal of the predetermined size was slowly pulled from the melt to obtain Lu. 2(0.899-v-w) Y 0.2 Ce 0.002 Ni 2v H 2v Yb 2w SiO5 crystals.

[0090] Table 7 shows the afterglow intensity of Ni, Yb, and H co-doped LYSO:Ce crystals with different doping concentrations, and the scintillation decay time when the scintillation light decays to 1 / e of the maximum intensity after radiative excitation (I=I0 / e). (When the H ion doping concentration in the table is 0, it means that no voltage was applied to the crucible / electrode during the preparation of the scintillation material, and the preparation atmosphere was pure nitrogen.)

[0091] Table 7

[0092] Ni / at.% Yb / at.% H / at.% Afterglow intensity / ppm@10ms Afterglow intensity / ppm@20ms Scintillation decay time (I=I0 / e) / ns Comparative Example 7-1 0.1 0.2 0 1413 537 25.1 Example 7-1 0.1 0.2 0.1 178 19 14.6 Example 7-2 0.3 0.4 0.3 135 16 10.9 Example 7-3 0.6 0.6 0.6 121 15 7.8 Example 7-4 1.0 2.0 1.0 100 14 4.1 Example 7-5 2.0 5.0 2.0 98 13 2.0

[0093] Example 8 (Preparation of Ni, Ho, H co-doped LYSO:Ce scintillation material)

[0094] Scintillation ceramics: Lu₂O₃ : Y₂O₃ : CeO₂ : NiO : Ho₂O₃ : SiO₂ = (0.899-vw) : 0.1 : 0.002 : 2v : w : 1 (v values ​​are 0.001, 0.003, 0.006, 0.01, 0.02; w values ​​are 0.002, 0.004, 0.006, 0.02, 0.05 respectively). After thorough mixing, the mixture was pressed into blocks under cold isostatic pressing at 250 MPa. The pressed mixture was then placed in a tube furnace, and the sample was placed on a negative bias electrode material with a voltage of -100V to -400V. A protective gas consisting mainly of nitrogen and containing at least 50 ppm hydrogen was introduced. The mixture was calcined at 1600 °C for 10 h to undergo a solid-state reaction, yielding Lu₂O₃. 2(0.899-v-w) Y 0.2 Ce 0.002 Ni 2v H 2v Ho 2w SiO5 scintillation ceramics.

[0095] Table 8 shows the afterglow intensity of Ni, Ho, and H co-doped LYSO:Ce ceramics with different doping concentrations, as well as the scintillation decay time when the scintillation light decays to 1 / e of the maximum intensity after radiation excitation (I=I0 / e). (When the H ion doping concentration in the table is 0, it means that no voltage was applied to the crucible / electrode during the preparation of the scintillation material, and the preparation atmosphere was pure nitrogen.)

[0096] Table 8

[0097] Ni / at.% Ho / at.% H / at.% Afterglow intensity / ppm@10ms Afterglow intensity / ppm@20ms Scintillation decay time (I=I0 / e) / ns Comparative Example 8-1 0.1 0.2 0 1186 397 23.7 Example 8-1 0.1 0.2 0.1 198 19 15.3 Example 8-2 0.3 0.4 0.3 159 17 10.8 Example 8-3 0.6 0.6 0.6 133 14 7.6 Example 8-4 1.0 2.0 1.0 119 14 4.7 Example 8-5 2.0 5.0 2.0 107 12 2.8

[0098] Example 9 (Preparation of Ni, Pr, H co-doped LYSO:Ce scintillation material)

[0099] Scintillation ceramic: The materials were prepared by mass ratio of Lu₂O₃ : Y₂O₃ : CeO₂ : NiO : PrN : SiO₂ = (0.899-vw) : 0.1 : 0.002 : 2v : w : 1 (v values ​​were 0.001, 0.003, 0.006, 0.01, 0.02; w values ​​were 0.002, 0.004, 0.006, 0.02, 0.05). After thorough mixing, the mixture was pressed into blocks under cold isostatic pressing at 250 MPa. The pressed mixture was then placed in a tube furnace, and the sample was placed on a negative bias electrode material with a voltage of -100V to -400V. A protective gas consisting mainly of nitrogen and containing at least 50 ppm hydrogen was introduced. The mixture was calcined at 1600 °C for 10 h to undergo a solid-state reaction, yielding Lu₂O₃. 2(0.899-v-w) Y 0.2 Ce0.002 Ni 2v H 2v Pr 2w SiO5 scintillation ceramics.

[0100] Table 9 shows the afterglow intensity of Ni, Pr, and H co-doped LYSO:Ce ceramics with different doping concentrations, as well as the scintillation decay time when the scintillation light decays to 1 / e of the maximum intensity after radiative excitation (I=I0 / e). (When the H ion doping concentration in the table is 0, it means that no voltage was applied to the crucible / electrode during the preparation of the scintillation material, and the preparation atmosphere was pure nitrogen.)

[0101] Table 9

[0102] Ni / at.% Pr / at.% H / at.% Afterglow intensity / ppm@10ms Afterglow intensity / ppm@20ms Scintillation decay time (I=I0 / e) / ns Comparative Example 9-1 0.1 0.2 0 1365 419 25.1 Example 9-1 0.1 0.2 0.1 179 20 14.6 Example 9-2 0.3 0.4 0.3 156 17 11.2 Example 9-3 0.6 0.6 0.6 121 14 6.2 Example 9-4 1.0 2.0 1.0 112 14 3.6 Example 9-5 2.0 5.0 2.0 107 12 2.7

[0103] Example 10 (Preparation of Al, Yb, H co-doped LYSO:Ce scintillation material)

[0104] Scintillation ceramic: The following formula is used: Lu₂O₃ : Y₂O₃ : CeO₂ : Yb₂O₃ : SiO₂ : Al₂O₃ = (0.899-w) : 0.1 : 0.002 : w : (1-y) : y / 2 (y values ​​are 0.001, 0.003, 0.006, 0.01, 0.02; w values ​​are 0.002, 0.004, 0.006, 0.02, 0.05). After thorough mixing, the mixture is pressed into blocks under cold isostatic pressing at 250 MPa. The pressed mixture is then placed in a tube furnace, and the sample is placed on a negative bias electrode material with a voltage of -100V to -400V. A protective gas consisting mainly of nitrogen and containing at least 50 ppm hydrogen is introduced, and the mixture is calcined at 1600 °C for 10 minutes. h undergoes a solid-state reaction to obtain Lu 2(0.899-v-w) Y 0.2 Ce 0.002 Yb 2w H y Si 1-y Al y O5 Sparkling Ceramic.

[0105] Table 10 shows the afterglow intensity of Al, Yb, and H co-doped LYSO:Ce ceramics with different doping concentrations, as well as the scintillation decay time when the scintillation light decays to 1 / e of the maximum intensity after radiative excitation (I=I0 / e). (When the H ion doping concentration in the table is 0, it means that no voltage was applied to the crucible / electrode during the preparation of the scintillation material, and the preparation atmosphere was pure nitrogen.)

[0106] Table 10

[0107] Al / at.% Yb / at.% H / at.% Afterglow intensity / ppm@10ms Afterglow intensity / ppm@20ms Scintillation decay time (I=I0 / e) / ns Comparative Example 10-1 0.1 0.2 0 1392 428 26.3 Example 10-1 0.1 0.2 0.1 183 20 14.3 Example 10-2 0.3 0.4 0.3 155 17 12.2 Example 10-3 0.6 0.6 0.6 134 16 7.6 Example 10-4 1.0 2.0 1.0 126 13 5.0 Examples 10-5 2.0 5.0 2.0 102 13 3.2

[0108] Example 11 (Preparation of Al, Ho, H co-doped LYSO:Ce scintillation material)

[0109] Scintillation ceramics: The following formula was prepared by mass ratio of Lu₂O₃ : Y₂O₃ : CeO₂ : Ho₂O₃ : SiO₂ : Al₂O₃ = (0.899-w) : 0.1 : 0.002 : w : (1-y) : y / 2 (y values ​​are 0.001, 0.003, 0.006, 0.01, 0.02; w values ​​are 0.002, 0.004, 0.006, 0.02, 0.05). After thorough mixing, the mixture was pressed into blocks under cold isostatic pressing at 250 MPa. The pressed mixture was then placed in a tube furnace, and the sample was placed on a negative bias electrode material with a voltage of -100V to -400V. A protective gas consisting mainly of nitrogen and containing at least 50 ppm hydrogen was introduced. The mixture was calcined at 1600 °C for 10 h to undergo a solid-state reaction, yielding Lu₂O₃. 2(0.899-w) Y 0.2 Ce 0.002 Ho 2w H y Si 1-y Al y O5 Sparkling Ceramic.

[0110] Table 11 shows the afterglow intensity of Al, Ho, and H co-doped LYSO:Ce ceramics with different doping concentrations, as well as the scintillation decay time when the scintillation light decays to 1 / e of the maximum intensity after radiative excitation (I=I0 / e). (When the H ion doping concentration in the table is 0, it means that no voltage was applied to the crucible / electrode during the preparation of the scintillation material, and the preparation atmosphere was pure nitrogen.)

[0111] Table 11

[0112] Al / at.% Ho / at.% H / at.% Afterglow intensity / ppm@10ms Afterglow intensity / ppm@20ms Scintillation decay time (I=I0 / e) / ns Comparative Example 11-1 0.1 0.2 0 1315 424 24.1 Example 11-1 0.1 0.2 0.1 200 19 14.4 Example 11-2 0.3 0.4 0.3 156 16 10.6 Examples 11-3 0.6 0.6 0.6 127 15 7.7 Examples 11-4 1.0 2.0 1.0 119 14 5.5 Examples 11-5 2.0 5.0 2.0 111 13 2.5

[0113] Example 12 (Preparation of Al, Ca, Yb, H co-doped LYSO:Ce scintillation material)

[0114] Scintillation ceramic: Molar ratio of Lu₂O₃ : Y₂O₃ : CeO₂ : CaO : Yb₂O₃ : SiO₂ : Al₂O₃ = (0.899-vw) : 0.1 : 0.002 : 2v : w : (1-y) : The ingredients were prepared by mixing y / 2 (y takes values ​​of 0.003, 0.003, 0.003, 0.006, and 0.01; v takes values ​​of 0.001, 0.001, 0.003, 0.003, and 0.004; and w takes values ​​of 0.002, 0.004, 0.004, 0.004, and 0.02). After thorough mixing, the mixture was placed in a tube furnace. The sample was placed on a negative bias electrode material with a voltage of -100V to -400V, and a protective gas consisting mainly of nitrogen and containing hydrogen with a volume concentration of at least 50ppm was introduced. The mixture was calcined at 1600 °C for 10 h to undergo a solid-state reaction, yielding Lu. 2(0.899-v-w) Y 0.2 Ce 0.002 Ca 2v H 2v+y Yb 2w Si 1- y Al y O5 Sparkling Ceramic.

[0115] Table 12 shows the afterglow intensity of Al, Ca, Yb, and H co-doped LYSO:Ce ceramics with different doping concentrations, as well as the scintillation decay time when the scintillation light decays to 1 / e of the maximum intensity after radiation excitation (I=I0 / e). (When the H ion doping concentration in the table is 0, it means that no voltage was applied to the crucible / electrode during the preparation of the scintillation material, and the preparation atmosphere was pure nitrogen.)

[0116] Table 12

[0117] Ca / at.% Al / at.% Yb / at.% H / at.% Afterglow intensity / ppm@10ms Afterglow intensity / ppm@20ms Scintillation decay time (I=I0 / e) / ns Comparative Example 12-1 0.1 0.3 0.2 0 1319 427 24.2 Example 12-1 0.1 0.3 0.2 0.4 195 19 14.2 Example 12-2 0.1 0.3 0.4 0.4 193 18 12.7 Example 12-3 0.3 0.3 0.4 0.6 154 16 8.1 Examples 12-4 0.3 0.6 0.4 0.9 150 14 4.8 Examples 12-5 0.4 1.0 2.0 1.4 126 13 3.2

[0118] Example 13 (Preparation of LYSO:Ce scintillation materials co-doped with Al, Ca, Yb, and H at different Ce concentrations)

[0119] Crystals: Prepare the mixture by mass ratio of Lu₂O₃ : Y₂O₃ : CeO₂ : CaO : Yb₂O₃ : SiO₂ : Al₂O₃ = (0.9-uvw) : 0.1 : 2u : 2v : w : (1-y) : y / 2 (where u takes values ​​of 0.0003, 0.001, 0.002, 0.005, 0.01; y takes values ​​of 0.003, 0.003, 0.003, 0.006, 0.01; v takes values ​​of 0.001, 0.001, 0.003, 0.003, 0.004; and w takes values ​​of 0.002, 0.004, 0.004, 0.004, 0.02). After thorough mixing, heat the mixture at 250°C. The sample was pressed into a block under cold isostatic pressing at MPa, placed in an iridium crucible, and a negative bias voltage of -100V to -400V was applied to the crucible. A protective gas consisting mainly of nitrogen and containing at least 50ppm hydrogen was introduced into a crystal preparation furnace. The sample was induction heated to 1900~2200℃ and fully melted. After seeding, a crystal of the predetermined size was slowly pulled from the melt to obtain Lu. 2(0.899-v-w) Y 0.2 Ce 2u Ca 2v H 2v+y Yb 2w Si 1-y Al y O5 crystals.

[0120] Table 13 shows the afterglow intensity of Al, Ca, Yb, and H co-doped LYSO:Ce crystals with different Ce doping concentrations, and the scintillation decay time when the scintillation light decays to 1 / e of the maximum intensity after radiative excitation (I=I0 / e).

[0121] Table 13

[0122] Ce / at.% Ca / at.% Al / at.% Yb / at.% H / at.% Afterglow intensity / ppm@10ms Afterglow intensity / ppm@20ms Scintillation decay time (I=I0 / e) / ns Example 13-1 0.03 0.1 0.3 0.2 0.4 214 23 15.0 Example 13-2 0.1 0.1 0.3 0.4 0.4 193 18 12.7 Example 13-3 0.2 0.3 0.3 0.4 0.6 140 15 7.3 Examples 13-4 0.5 0.3 0.6 0.4 0.9 135 13 4.1 Examples 13-5 1 0.4 1 2 1.4 114 12 2.2

[0123] Example 14 (Preparation of Al, Ca, Ho, H co-doped LYSO:Ce scintillation material)

[0124] Scintillation ceramics: The following formula is used: Lu₂O₃ : Y₂O₃ : CeO₂ : CaO : Ho₂O₃ : SiO₂ : Al₂O₃ = (0.899-vw) : 0.1 : 0.002 : 2v : w : (1-y) : y / 2 (y takes values ​​of 0.003, 0.003, 0.003, 0.006, 0.01; v takes values ​​of 0.001, 0.001, 0.003, 0.003, 0.004; w takes values ​​of 0.002, 0.004, 0.004, 0.004, 0.02). After thorough mixing, the mixture is heated to 250°C. The mixture was pressed into blocks under cold isostatic pressing at MPa, and then placed in a tube furnace. The sample was placed on a negative bias electrode material with a voltage of -100V to -400V, and a protective gas consisting mainly of nitrogen and containing at least 50ppm hydrogen was introduced. The mixture was calcined at 1600 °C for 10 h to undergo a solid-state reaction, yielding Lu. 2(0.899-v-w) Y 0.2 Ce 0.002 Ca 2v H 2v+y Ho 2w Si 1-y Al y O5 Sparkling Ceramic.

[0125] Table 14 shows the afterglow intensity of Al, Ca, Ho, and H co-doped LYSO:Ce ceramics with different doping concentrations, as well as the scintillation decay time when the scintillation light decays to 1 / e of the maximum intensity after radiation excitation (I=I0 / e). (When the H ion doping concentration in the table is 0, it means that no voltage was applied to the crucible / electrode during the preparation of the scintillation material, and the preparation atmosphere was pure nitrogen.)

[0126] Table 14

[0127] Ca / at.% Al / at.% Ho / at.% H / at.% Afterglow intensity / ppm@10ms Afterglow intensity / ppm@20ms Scintillation decay time (I=I0 / e) / ns Comparative Example 14-1 0.1 0.3 0.2 0 1366 441 22.3 Example 14-1 0.1 0.3 0.2 0.4 187 20 14.5 Example 14-2 0.1 0.3 0.4 0.4 168 17 11.0 Example 14-3 0.3 0.3 0.4 0.6 147 15 7.4 Example 14-4 0.3 0.6 0.4 0.9 134 12 5.8 Examples 14-5 0.4 1.0 2.0 1.4 115 12 4.2

[0128] Example 15 (Preparation of Al, Ca, Pr, H co-doped LYSO:Ce scintillation material)

[0129] Scintillation ceramics: molar ratio of Lu₂O₃ : Y₂O₃ : CeO₂ : CaO : Pr₆O 11The following formula was used: SiO2 : Al2O3 = (0.899-vw) : 0.1 : 0.002 : 2v : w / 3 : (1-y) : y / 2 (y takes values ​​of 0.003, 0.003, 0.003, 0.006, 0.01 respectively; v takes values ​​of 0.001, 0.001, 0.003, 0.003, 0.004 respectively; w takes values ​​of 0.002, 0.004, 0.004, 0.004, 0.02 respectively). After thorough mixing, the mixture was pressed into blocks under cold isostatic pressing at 250 MPa. The pressed mixture was then placed in a tube furnace, and the sample was placed on a negative bias electrode material with a voltage of -100V to -400V. A protective gas consisting mainly of nitrogen and containing hydrogen with a volume concentration of at least 50 ppm was introduced, and the mixture was heated to 1600 °C. Calcination at ℃ for 10 h resulted in a solid-state reaction, yielding Lu. 2(0.899-v-w) Y 0.2 Ce 0.002 Ca 2v H 2v+y Pr 2w Si 1-y Al y O5 Sparkling Ceramic.

[0130] Table 15 shows the afterglow intensity of Al, Ca, Pr, and H co-doped LYSO:Ce ceramics with different doping concentrations, as well as the scintillation decay time when the scintillation light decays to 1 / e of the maximum intensity after radiative excitation (I=I0 / e). (When the H ion doping concentration in the table is 0, it means that no voltage was applied to the crucible / electrode during the preparation of the scintillation material, and the preparation atmosphere was pure nitrogen.)

[0131] Table 15

[0132] Ca / at.% Al / at.% Pr / at.% H / at.% Afterglow intensity / ppm@10ms Afterglow intensity / ppm@20ms Scintillation decay time (I=I0 / e) / ns Comparative Example 15-1 0.1 0.3 0.2 0 1431 402 25.2 Example 15-1 0.1 0.3 0.2 0.4 187 18 13.6 Example 15-2 0.1 0.3 0.4 0.4 153 15 10.1 Example 15-3 0.3 0.3 0.4 0.6 141 15 6.7 Example 15-4 0.3 0.6 0.4 0.9 135 14 5.8 Example 15-5 0.4 1.0 2.0 1.4 118 13 4.0

[0133] Example 16 (Preparation of Al, Mg, Yb, H co-doped LYSO:Ce scintillation material)

[0134] Scintillation ceramics: The following formula is used: Lu₂O₃ : Y₂O₃ : CeO₂ : MgO : Yb₂O₃ : SiO₂ : Al₂O₃ = (0.899-vw) : 0.1 : 0.002 : 2v : w : (1-y) : y / 2 (y takes values ​​of 0.003, 0.003, 0.003, 0.006, 0.01; v takes values ​​of 0.001, 0.001, 0.003, 0.003, 0.004; w takes values ​​of 0.002, 0.004, 0.004, 0.004, 0.02). After thorough mixing, the mixture is heated to 250°C. The mixture was pressed into blocks under cold isostatic pressing at MPa, and then placed in a tube furnace. The sample was placed on a negative bias electrode material with a voltage of -100V to -400V, and a protective gas consisting mainly of nitrogen and containing at least 50ppm hydrogen was introduced. The mixture was calcined at 1600 °C for 10 h to undergo a solid-state reaction, yielding Lu. 2(0.899-v-w) Y 0.2 Ce 0.002 Mg 2v H 2v+y Yb 2w Si 1-y Al y O5 Sparkling Ceramic.

[0135] Table 16 shows the afterglow intensity of Al, Mg, Yb, and H co-doped LYSO:Ce ceramics with different doping concentrations, as well as the scintillation decay time when the scintillation light decays to 1 / e of the maximum intensity after radiation excitation (I=I0 / e). (When the H ion doping concentration in the table is 0, it means that no voltage was applied to the crucible / electrode during the preparation of the scintillation material, and the preparation atmosphere was pure nitrogen.)

[0136] Table 16

[0137] Mg / at.% Al / at.% Yb / at.% H / at.% Afterglow intensity / ppm@10ms Afterglow intensity / ppm@20ms Scintillation decay time (I=I0 / e) / ns Comparative Example 16-1 0.1 0.3 0.2 0 1533 479 23.4 Example 16-1 0.1 0.3 0.2 0.4 197 20 14.8 Example 16-2 0.1 0.3 0.4 0.4 156 15 8.1 Example 16-3 0.3 0.3 0.4 0.6 141 14 5.6 Example 16-4 0.3 0.6 0.4 0.9 116 13 4.1 Example 16-5 0.4 1.0 2.0 1.4 105 13 2.2

[0138] Example 17 (Preparation of Al, Ni, Yb, H co-doped LYSO:Ce scintillation material)

[0139] Scintillation ceramic: The following formula is used: Lu₂O₃ : Y₂O₃ : CeO₂ : NiO : Yb₂O₃ : SiO₂ : Al₂O₃ = (0.899-vw) : 0.1 : 0.002 : 2v : w : (1-y) : y / 2 (y takes values ​​of 0.003, 0.003, 0.003, 0.006, 0.01, 0.01, 0.02; v takes values ​​of 0.001, 0.001, 0.003, 0.003, 0.004, 0.01, 0.02; w takes values ​​of 0.002, 0.004, 0.004, 0.004, 0.02, 0.02, 0.05). After thorough mixing, the mixture is heated to 250°C. The mixture was pressed into blocks under cold isostatic pressing at MPa, and then placed in a tube furnace. The sample was placed on a negative bias electrode material with a voltage of -100V to -400V, and a protective gas consisting mainly of nitrogen and containing at least 50ppm hydrogen was introduced. The mixture was calcined at 1600 °C for 10 h to undergo a solid-state reaction, yielding Lu. 2(0.899-v-w) Y 0.2 Ce 0.002 Ni 2v H 2v+y Yb 2w Si 1-y Al y O5 Sparkling Ceramic.

[0140] Table 17 shows the afterglow intensity of Al, Ni, Yb, and H co-doped LYSO:Ce ceramics with different doping concentrations, as well as the scintillation decay time when the scintillation light decays to 1 / e of the maximum intensity after radiative excitation (I=I0 / e). (When the H ion doping concentration in the table is 0, it means that no voltage was applied to the crucible / electrode during the preparation of the scintillation material, and the preparation atmosphere was pure nitrogen.)

[0141] Table 17

[0142] Ni / at.% Al / at.% Yb / at.% H / at.% Afterglow intensity / ppm@10ms Afterglow intensity / ppm@20ms Scintillation decay time (I=I0 / e) / ns Comparative Example 17-1 0.1 0.3 0.2 0 1697 449 23.2 Example 17-1 0.1 0.3 0.2 0.4 182 20 14.9 Example 17-2 0.1 0.3 0.4 0.4 167 15 11.7 Example 17-3 0.3 0.3 0.4 0.6 153 15 7.9 Example 17-4 0.3 0.6 0.4 0.9 128 14 7.5 Example 17-5 0.4 1.0 2.0 1.4 108 14 5.0 Example 17-6 1.0 1.0 2.0 2.0 100 12 4.1 Example 17-7 2.0 2.0 5.0 4.0 93 10 3.8

[0143] Example 18 (Preparation of Al, Ni, Ho, H co-doped LYSO:Ce scintillation material)

[0144] Scintillation ceramics: The following formula is used: Lu₂O₃ : Y₂O₃ : CeO₂ : NiO : Ho₂O₃ : SiO₂ : Al₂O₃ = (0.899-vw) : 0.1 : 0.002 : 2v : w : (1-y) : y / 2 (y takes values ​​of 0.003, 0.003, 0.003, 0.006, 0.01, 0.01, 0.02; v takes values ​​of 0.001, 0.001, 0.003, 0.003, 0.004, 0.01, 0.02; w takes values ​​of 0.002, 0.004, 0.004, 0.004, 0.02, 0.02, 0.05). After thorough mixing, the mixture is heated to 250°C. The mixture was pressed into blocks under cold isostatic pressing at MPa, and then placed in a tube furnace. The sample was placed on a negative bias electrode material with a voltage of -100V to -400V, and a protective gas consisting mainly of nitrogen and containing at least 50ppm hydrogen was introduced. The mixture was calcined at 1600 °C for 10 h to undergo a solid-state reaction, yielding Lu. 2(0.899-v-w) Y 0.2 Ce 0.002 Ni 2v H 2v+y Ho 2w Si 1-y Al y O5 Sparkling Ceramic.

[0145] Table 18 shows the afterglow intensity of Al, Ni, Ho, and H co-doped LYSO:Ce ceramics with different doping concentrations, as well as the scintillation decay time when the scintillation light decays to 1 / e of the maximum intensity after radiation excitation (I=I0 / e). (When the H ion doping concentration in the table is 0, it means that no voltage was applied to the crucible / electrode during the preparation of the scintillation material, and the preparation atmosphere was pure nitrogen.)

[0146] Table 18

[0147] Ni / at.% Al / at.% Ho / at.% H / at.% Afterglow intensity / ppm@10ms Afterglow intensity / ppm@20ms Scintillation decay time (I=I0 / e) / ns Comparative Example 18-1 0.1 0.3 0.2 0 1302 394 21.4 Example 18-1 0.1 0.3 0.2 0.4 198 20 15.0 Example 18-2 0.1 0.3 0.4 0.4 167 18 14.1 Example 18-3 0.3 0.3 0.4 0.6 149 14 9.2 Example 18-4 0.3 0.6 0.4 0.9 134 13 5.8 Example 18-5 0.4 1.0 2.0 1.4 117 12 4.4 Example 18-6 1.0 1.0 2.0 2.0 106 12 3.6 Example 18-7 2.0 2.0 5.0 4.0 94 10 3.1

[0148] Example 19 (Preparation of Al, Ni, Pr, H co-doped LYSO:Ce scintillation material)

[0149] Scintillation ceramics: molar ratio of Lu₂O₃ : Y₂O₃ : CeO₂ : NiO : Pr₆O 11: SiO2 : Al2O3 =(0.899-vw) : 0.1 : 0.002 : 2v : w / 3 : (1-y) : The mixture was prepared by adding y / 2 (where y takes values ​​of 0.003, 0.003, 0.003, 0.006, 0.01, 0.01, and 0.02; v takes values ​​of 0.001, 0.001, 0.003, 0.003, 0.004, 0.01, and 0.02; and w takes values ​​of 0.002, 0.004, 0.004, 0.004, 0.02, 0.02, and 0.05). After thorough mixing, the mixture was pressed into blocks under cold isostatic pressing at 250 MPa. The pressed mixture was then placed in a tube furnace, and the sample was placed on a negative bias electrode material with a voltage of -100V to -400V. A protective gas consisting mainly of nitrogen and containing hydrogen with a volume concentration of at least 50 ppm was introduced. The mixture was calcined at 1600 °C for 10 h to undergo a solid-phase reaction, yielding Lu. 2(0.899-v-w) Y 0.2 Ce 0.002 Ni 2v H 2v+y Pr 2w Si 1- y Al y O5 Sparkling Ceramic.

[0150] Table 19 shows the afterglow intensity of Al, Ni, Pr, and H co-doped LYSO:Ce ceramics with different doping concentrations, as well as the scintillation decay time when the scintillation light decays to 1 / e of the maximum intensity after radiative excitation (I=I0 / e). (When the H ion doping concentration in the table is 0, it means that no voltage was applied to the crucible / electrode during the preparation of the scintillation material, and the preparation atmosphere was pure nitrogen.)

[0151] Table 19

[0152] Ni / at.% Al / at.% Pr / at.% H / at.% Afterglow intensity / ppm@10ms Afterglow intensity / ppm@20ms Scintillation decay time (I=I0 / e) / ns Comparative Example 19-1 0.1 0.3 0.2 0 1311 413 27.7 Example 19-1 0.1 0.3 0.2 0.4 189 19 14.7 Example 19-2 0.1 0.3 0.4 0.4 135 16 13.2 Example 19-3 0.3 0.3 0.4 0.6 135 16 8.6 Example 19-4 0.3 0.6 0.4 0.9 127 13 6.4 Example 19-5 0.4 1.0 2.0 1.4 116 13 5.1 Example 19-6 1.0 1.0 2.0 2.0 104 10 4.0 Example 19-7 2.0 2.0 5.0 4.0 93 7 3.3

[0153] Example 20 (Preparation of Ni, Ho, H co-doped LGSO:Ce scintillation material)

[0154] Scintillation ceramic: The materials are prepared by mass ratio of Lu₂O₃ : Gd₂O₃ : CeO₂ : NiO : Ho₂O₃ : SiO₂ = (0.799-vw) : 0.2 : 0.002 : 2v : w : 1 (v values ​​are 0.002, 0.003, 0.004, 0.004, 0.01, 0.02; w values ​​are 0.004, 0.006, 0.02, 0.05, 0.05, 0.05). After thorough mixing, the mixture is pressed into blocks under cold isostatic pressing at 250 MPa. The pressed mixture is then placed in a tube furnace, and the sample is placed on a negative bias electrode material with a voltage of -100V to -400V. A protective gas consisting mainly of nitrogen and containing at least 50 ppm hydrogen is introduced, and the mixture is calcined at 1600 °C for 10 minutes. h undergoes a solid-state reaction to obtain Lu 2(0.799-v-w) Gd 0.4 Ce 0.002 Ni v H 2v Ho 2w SiO5 scintillation ceramics.

[0155] Table 20 shows the afterglow intensity of Ni, Ho, and H co-doped LGSO:Ce ceramics with different doping concentrations, as well as the scintillation decay time when the scintillation light decays to 1 / e of the maximum intensity after radiative excitation (I=I0 / e). (When the H ion doping concentration in the table is 0, it means that no voltage was applied to the crucible / electrode during the preparation of the scintillation material, and the preparation atmosphere was pure nitrogen.)

[0156] Table 20

[0157] Ni / at.% Ho / at.% H / at.% Afterglow intensity / ppm@10ms Afterglow intensity / ppm@20ms Scintillation decay time (I=I0 / e) / ns Comparative Example 20-1 0.2 0.4 0 1173 311 23.6 Example 20-1 0.2 0.4 0.2 125 16 14.7 Example 20-2 0.3 0.6 0.3 111 16 13.2 Example 20-3 0.4 2.0 0.4 99 14 11.3 Example 20-4 0.4 5.0 0.4 91 13 9.7 Example 20-5 1.0 5.0 1.0 86 10 7.5 Example 20-6 2.0 5.0 2.0 73 9 6.3

[0158] Example 21 (Preparation of Ni, Ho, H co-doped LSO:Ce scintillation material)

[0159] Scintillation ceramic: The materials were prepared by mass ratio of Lu₂O₃ : CeO₂ : NiO : Ho₂O₃ : SiO₂ = (0.999-vw) : 0.002 : 2v : w : 1 (v values ​​were 0.001, 0.003, 0.006, 0.01, 0.02; w values ​​were 0.002, 0.004, 0.006, 0.02, 0.05). After thorough mixing, the mixture was pressed into blocks under cold isostatic pressing at 250 MPa. The pressed mixture was then placed in a tube furnace, and the sample was placed on a negative bias electrode material with a voltage of -100V to -400V. A protective gas consisting mainly of nitrogen and containing at least 50 ppm hydrogen was introduced. The mixture was calcined at 1600 °C for 10 h to undergo a solid-state reaction, yielding Lu₂O₃. 2(0.999-v-w) Ce 0.002Ni 2v H 2v Ho 2w SiO5 scintillation ceramics.

[0160] Table 21 shows the afterglow intensity of Ni, Ho, and H co-doped LSO:Ce ceramics with different doping concentrations, as well as the scintillation decay time when the scintillation light decays to 1 / e of the maximum intensity after radiative excitation (I=I0 / e). (When the H ion doping concentration in the table is 0, it means that no voltage was applied to the crucible / electrode during the preparation of the scintillation material, and the preparation atmosphere was pure nitrogen.)

[0161] Table 21

[0162] Ni / at.% Ho / at.% H / at.% Afterglow intensity / ppm@10ms Afterglow intensity / ppm@20ms Scintillation decay time (I=I0 / e) / ns Comparative Example 21-1 0.1 0.2 0 1156 390 22.5 Example 21-1 0.1 0.2 0.1 189 18 14.7 Example 21-2 0.3 0.4 0.3 163 15 10.2 Examples 21-3 0.6 0.6 0.6 137 14 7.1 Examples 21-4 1.0 2.0 1.0 121 13 4.2 Examples 21-5 2.0 5.0 2.0 109 12 2.1

[0163] Example 22 (Preparation of Ni, Ho, H co-doped YSO:Ce scintillation material)

[0164] Scintillation ceramics: The materials were prepared by mass ratio Y₂O₃ : CeO₂ : NiO : Ho₂O₃ : SiO₂ = (0.999-vw) : 0.002 : 2v : w : 1 (v values ​​were 0.006, 0.01, and 0.02; w values ​​were 0.006, 0.02, and 0.05). After thorough mixing, the mixture was pressed into blocks under cold isostatic pressing at 250 MPa. The pressed mixture was then placed in a tube furnace, and the sample was placed on a negative bias electrode material with a voltage of -100V to -400V. A protective gas consisting mainly of nitrogen and containing at least 50 ppm hydrogen was introduced. The mixture was calcined at 1600 °C for 10 h to undergo a solid-state reaction, yielding Y₂O₃. 2(0.999-v-w) Ce 0.002 Ni 2v H 2v Ho 2w SiO5 scintillation ceramics.

[0165] Table 22 shows the afterglow intensity of Ni, Ho, and H co-doped YSO:Ce ceramics with different doping concentrations, as well as the scintillation decay time when the scintillation light decays to 1 / e of the maximum intensity after radiative excitation (I=I0 / e). (When the H ion doping concentration in the table is 0, it means that no voltage was applied to the crucible / electrode during the preparation of the scintillation material, and the preparation atmosphere was pure nitrogen.)

[0166] Table 22

[0167] Ni / at.% Ho / at.% H / at.% Afterglow intensity / ppm@10ms Afterglow intensity / ppm@20ms Scintillation decay time (I=I0 / e) / ns Comparative Example 22-1 0.6 0.6 0 533 252 25.3 Example 22-1 0.6 0.6 0.6 168 18 14.8 Example 22-2 1.0 2.0 1.0 144 16 12.1 Example 22-3 2.0 5.0 2.0 126 15 10.3

[0168] Example 23 (Preparation of Ni, Ho, H co-doped GSO:Ce scintillation material)

[0169] Scintillation ceramics: Gd₂O₃ : CeO₂ : NiO : Ho₂O₃ : SiO₂ = (0.999-vw) : 0.002 : 2v : w : 1 (v values ​​are 0.003, 0.006, 0.01, 0.02; w values ​​are 0.004, 0.006, 0.02, 0.05). After thorough mixing, the mixture was pressed into blocks under cold isostatic pressing at 250 MPa. The pressed mixture was then placed in a tube furnace, and the sample was placed on a negative bias electrode material with a voltage of -100V to -400V. A protective gas consisting mainly of nitrogen and containing at least 50 ppm hydrogen was introduced. The mixture was calcined at 1600 °C for 10 h to undergo a solid-state reaction, yielding Lu. 2(0.999-v-w) Ce 0.002 Ni 2v H 2v Ho 2w SiO5 scintillation ceramics.

[0170] Table 23 shows the afterglow intensity of Ni, Ho, and H co-doped LSO:Ce ceramics with different doping concentrations, as well as the scintillation decay time when the scintillation light decays to 1 / e of the maximum intensity after radiative excitation (I=I0 / e). (When the H ion doping concentration in the table is 0, it means that no voltage was applied to the crucible / electrode during the preparation of the scintillation material, and the preparation atmosphere was pure nitrogen.)

[0171] Table 23

[0172] Ni / at.% Ho / at.% H / at.% Afterglow intensity / ppm@10ms Afterglow intensity / ppm@20ms Scintillation decay time (I=I0 / e) / ns Comparative Example 23-1 0.3 0.4 0 893 279 25.3 Example 23-1 0.3 0.4 0.3 196 19 14.9 Example 23-2 0.6 0.6 0.6 187 17 13.1 Example 23-3 1.0 2.0 1.0 175 16 11.6 Example 23-4 2.0 5.0 2.0 168 16 9.3

[0173] Example 24 (Preparation of Ca, Mg, Ho, H co-doped LYSO:Ce scintillation material)

[0174] Ceramics: The mass ratio of Lu₂O₃ : Y₂O₃ : CeO₂ : CaO : MgO : Ho₂O₃ : SiO₂ = (0.899 - v₁ - v₂ - w) : 0.1 : 0.002 : 2v₁ : 2v₂ : w : 1 (as shown in Table 24, v₁ takes values ​​of 0.0005, 0.001, 0.0015, 0.002, 0.002, 0.005; v₂ takes values ​​of 0.0005, 0.001, 0.0015, 0.002, 0.002, 0.005; w takes values ​​of 0.002, 0.004, 0.006, 0.02, 0.05, 0.05). After thorough mixing, heat at 250°C. The mixture was pressed into blocks under cold isostatic pressing at MPa, and then placed in a tube furnace. The sample was placed on a negative bias electrode material with a voltage of -100V to -400V, and a protective gas consisting mainly of nitrogen and containing at least 50ppm hydrogen was introduced. The mixture was calcined at 1600 °C for 10 h to undergo a solid-state reaction, yielding Lu. 2(0.899-v1-v2-w) Y 0.2 Ce 0.002 Ca 2v1 Mg 2v1 H 2(v1+v2) Ho 2w SiO5 ceramics.

[0175] Table 24 shows the afterglow intensity of Ca, Mg, Ho, and H co-doped LYSO:Ce ceramics with different doping concentrations, as well as the scintillation decay time when the scintillation light decays to 1 / e of the maximum intensity after radiative excitation (I=I0 / e). (When the H ion doping concentration in the table is 0, it means that no voltage was applied to the crucible / electrode during the preparation of the scintillation material, and the preparation atmosphere was pure nitrogen.)

[0176] Table 24

[0177] Ca / at.% Mg / at.% Ho / at.% H / at.% Afterglow intensity / ppm@10ms Afterglow intensity / ppm@20ms Scintillation decay time (I=I0 / e) / ns Comparative Example 24-1 0.05 0.05 0.2 0 1324 420 22.3 Example 24-1 0.05 0.05 0.2 0.1 186 19 14.5 Example 24-2 0.1 0.1 0.4 0.2 134 17 9.6 Example 24-3 0.15 0.15 0.6 0.3 109 15 6.9 Example 24-4 0.2 0.2 2 0.4 99 13 4.1 Examples 24-5 0.2 0.2 5 0.4 93 11 2.6 Examples 24-6 0.5 0.5 5 1 85 10 2.4

[0178] Example 25 (Preparation of Ca, Yb, Pr, H co-doped LYSO:Ce scintillation material)

[0179] Ceramics: Molar ratio of Lu₂O₃ : Y₂O₃ : CeO₂ : CaO : Yb₂O₃ : Pr₆O 11SiO2 = (0.899-v-w1-w2) : 0.1 : 0.002 : 2v : w1 : w2 / 3 : 1 (as shown in Table 25, v takes values ​​of 0.001, 0.003, and 0.006 respectively; w1 takes values ​​of 0.001, 0.002, and 0.003 respectively; w2 takes values ​​of 0.001, 0.002, and 0.003 respectively) was prepared and thoroughly mixed. The mixture was then pressed into blocks under cold isostatic pressing at 250 MPa. The pressed mixture was then placed in a tube furnace, and the sample was placed on a negative bias electrode material with a voltage of -100V to -400V. A protective gas consisting mainly of nitrogen and containing at least 50 ppm hydrogen was introduced. The mixture was calcined at 1600 ℃ for 10 h to undergo a solid-phase reaction, yielding Lu. 2(0.899-v-w1-w2) Y 0.2 Ce 0.002 Ca 2v H 2v Yb 2w1 Pr 2w2 SiO5 ceramics.

[0180] Table 25 shows the afterglow intensity of Ca, Yb, Pr, and H co-doped LYSO:Ce ceramics with different doping concentrations, as well as the scintillation decay time when the scintillation light decays to 1 / e of the maximum intensity after radiative excitation (I=I0 / e). (When the H ion doping concentration in the table is 0, it means that no voltage was applied to the crucible / electrode during the preparation of the scintillation material, and the preparation atmosphere was pure nitrogen.)

[0181] Table 25

[0182] Ca / at.% Yb / at.% Pr / at.% H / at.% Afterglow intensity / ppm@10ms Afterglow intensity / ppm@20ms Scintillation decay time (I=I0 / e) / ns Comparative Example 25-1 0.1 0.1 0.1 0 1403 531 26 Example 25-1 0.1 0.1 0.1 0.1 190 18 14.6 Example 25-2 0.3 0.3 0.3 0.3 107 13 6.3 Example 25-3 0.6 0.3 0.3 0.6 77 12 2.5

[0183] Example 26 (Influence of air atmosphere annealing on the properties of Ca, Ho, H co-doped LYSO:Ce scintillation materials)

[0184] The Lu co-doped with 0.1% Ca, 0.2% Ho, and 0.1% H prepared in Example 2 was used. 1.79 Y 0.2 Ce 0.002 Ca 0.002 H 0.002 Ho 0.004 SiO5 crystals were annealed in air at 1000℃, 1100℃, 1200℃, 1300℃, 1400℃, 1500℃ and 1600℃ respectively. The changes in afterglow intensity and scintillation decay time are shown in the table below.

[0185] Table 26 shows the effect of air atmosphere annealing on Lu 1.79 Y 0.2 Ce 0.002 Ca 0.002 H 0.002Ho 0.004 The study examines the effects of afterglow intensity on SiO5 crystals and the scintillation decay time when the scintillation light decays to 1 / e of its maximum intensity after radiative excitation (I=I0 / e). It is evident that the afterglow and scintillation decay performance of scintillation materials can be optimized through air annealing, i.e., reducing afterglow intensity and scintillation decay time. However, annealing temperatures above 1400℃ will deteriorate afterglow and scintillation decay performance due to hydrogen ion escape, i.e., significantly increasing afterglow intensity and scintillation decay time.

[0186] Table 26

[0187] Annealing temperature / °C Afterglow intensity / ppm@10ms Afterglow intensity / ppm@20ms Scintillation decay time (I=I0 / e) / ns Unannealed 198 20 13.4 1000 198 20 13.4 1100 196 20 13.4 1200 184 16 13.3 1300 180 13 13.2 1400 365 53 14.7 1500 827 227 18.5 1600 1147 389 20.1

[0188] Example 27 (Effect of air atmosphere annealing on the properties of Ca, Yb, H co-doped LYSO:Ce scintillation materials) Ca, Yb, H

[0189] The Lu co-doped with 0.1% Ca, 0.2% Yb, and 0.1% H prepared in Example 3 was used. 1.79 Y 0.2 Ce 0.002 Ca 0.002 H 0.002 Yb 0.004 SiO5 ceramics were annealed in air at 1000℃, 1100℃, 1200℃, 1300℃, 1400℃, 1500℃ and 1600℃ respectively. The changes in afterglow intensity and scintillation decay time are shown in the table below.

[0190] Table 27 shows the effect of air atmosphere annealing on Lu 1.79 Y 0.2 Ce 0.002 Ca 0.002 H 0.002 Yb 0.004 The study investigated the effects of afterglow intensity and scintillation decay time on SiO5 ceramics when the scintillation light decays to 1 / e of its maximum intensity after radiative excitation (I=I0 / e). It was found that scintillation materials can have their afterglow and scintillation decay performance optimized through air annealing, i.e., reducing afterglow intensity and scintillation decay time. However, annealing temperatures above 1400℃ lead to deterioration of these performances due to hydrogen ion escape, resulting in a significant increase in both afterglow intensity and scintillation decay time.

[0191] Table 27

[0192] Annealing temperature / °C Afterglow intensity / ppm@10ms Afterglow intensity / ppm@20ms Scintillation decay time (I=I0 / e) / ns Unannealed 190 20 13.5 1000 190 20 13.5 1100 185 19 13.3 1200 173 14 12.7 1300 160 11 11.2 1400 332 49 12.5 1500 795 212 18.3 1600 1213 513 22.2

[0193] Through the above embodiments, combined with different compositions and different processes, the ultra-low afterglow fast scintillation decay rare earth orthosilicate scintillation material of this application was prepared.

[0194] It should be noted that the performance conclusions of ceramics or crystals with certain compositions in Examples 1 to 27 are only recorded in the above embodiments. In fact, ceramics or crystals obtained with other compositions and other processes have the same results as those in Examples 1 to 27, and their details are omitted here.

[0195] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A rare-earth orthosilicate scintillation material with ultra-low afterglow and fast scintillation decay, characterized in that, The ultra-low afterglow fast scintillation decay rare-earth orthosilicate scintillation material is a scintillation material co-doped with hydrogen ion, strong oxygen vacancy trapping dopants, and strong carrier binding dopants. The chemical formula of the ultra-low afterglow fast scintillation decay rare-earth orthosilicate scintillation material based on the raw material ratio is RE. 2(1-u-v-w) Ce 2u M 2v H 2v+y N 2w Si 1-y Al y O5, where 0 < u ≤ 0.05, 0 ≤ v ≤ 0.02, 0 < w ≤ 0.05, 0 ≤ y ≤ 0.02, and v + y > 0, where H represents hydrogen, which is provided by the preparation atmosphere; RE represents a rare earth element, which is selected from at least one of lutetium, yttrium, gadolinium, and lanthanum. The strong oxygen vacancy trapping dopant element includes aluminum and / or M, wherein the M element is selected from at least one of magnesium, calcium, and nickel. The N represents a strongly carrier-bound dopant element, which is selected from at least one of ytterbium, praseodymium, and holmium.

2. The ultra-low afterglow fast scintillation decay rare-earth orthosilicate scintillation material according to claim 1, characterized in that, The strong oxygen vacancy trapping dopant element includes either aluminum or M, wherein aluminum at least partially occupies silicon lattice sites.

3. The ultra-low afterglow fast scintillation decay rare-earth orthosilicate scintillation material according to claim 1, characterized in that, The rare earth element is yttrium, lutetium, or a solid solution of both lutetium and yttrium.

4. The ultra-low afterglow fast scintillation decay rare-earth orthosilicate scintillation material according to claim 1, characterized in that, The rare earth element is a solid solution of lutetium and yttrium, wherein the molar ratio of lutetium to yttrium is (7~9):

1.

5. The ultra-low afterglow fast scintillation decay rare-earth orthosilicate scintillation material according to claim 1, characterized in that, 0.001≤u≤0.005, 0.001≤v≤0.02, 0.004≤w≤0.

05.

6. The ultra-low afterglow fast scintillation decay rare-earth orthosilicate scintillation material according to claim 5, characterized in that, 0.003≤y≤0.02。 7. A method for preparing an ultra-low afterglow fast scintillation decay rare-earth orthosilicate scintillation material, characterized in that, The preparation method for the ultra-low afterglow fast scintillation decay rare-earth orthosilicate scintillation material according to any one of claims 1 to 6, wherein the scintillation material is a scintillation ceramic, comprises the following steps: S1 Weigh the RE source compound, Ce source compound, strong oxygen vacancy trapping doped source compound, strong carrier binding doped source compound, and SiO2 respectively to make the chemical formula based on the raw material ratio RE 2(1-u-v-w) Ce 2u M 2v N 2w Si 1-y Al y O5, and mix all raw materials thoroughly to obtain a mixed powder; S2 After pressing the mixed powder obtained in step S1 into shape, scintillation ceramic sintering is performed. The main component of the sintering atmosphere is nitrogen, which contains hydrogen or hydrogen-containing gas with a volume concentration of at least 50 ppm. Interstitial hydrogen ions are introduced by high-temperature negative bias hydrogen ion enrichment method. Specifically, during the sintering process, the ceramic is placed on the electrode and a negative bias is applied. The solid-phase reaction is carried out at a temperature of 1400~1600℃ for 10~50h to obtain the scintillation ceramic. The negative bias is -100V~-400V.

8. A method for preparing an ultra-low afterglow fast scintillation decay rare-earth orthosilicate scintillation material, characterized in that, The preparation method for the ultra-low afterglow fast scintillation decay rare-earth orthosilicate scintillation material according to any one of claims 1 to 6, wherein the scintillation material is a scintillation crystal, comprises the following steps: S1 Weigh the RE source compound, Ce source compound, strong oxygen vacancy trapping doped source compound, strong carrier binding doped source compound, and SiO2 respectively to make the chemical formula based on the raw material ratio RE 2(1-u-v-w) Ce 2u M 2v N 2w Si 1-y Al y O5, and mix all raw materials thoroughly to obtain a mixed powder; S2 After pressing the mixed powder obtained in step S1 into shape, it is placed in a crucible and heated to 1900~2200℃ to melt and prepared by the Czochralski method. The main component of the preparation atmosphere is nitrogen, and it contains hydrogen or hydrogen-containing gas with a volume concentration of at least 50ppm. During the crystal preparation process, a negative bias voltage of -100V~-400V is applied at the crucible to introduce hydrogen ions into the melt and introduce hydrogen ions into the crystal during the crystal preparation process.

9. The preparation method of the ultra-low afterglow fast scintillation decay rare earth orthosilicate scintillation ceramic according to claim 7, characterized in that, The strong oxygen vacancy trapping doping source compound includes aluminum oxide and / or a compound containing element M, wherein the compound containing element M includes one or more of oxides, nitrides, silicates, and carbonates of element M; the strong carrier binding doping source compound includes one or more of oxides, nitrides, and carbonates of element N.

10. The method for preparing ultra-low afterglow fast scintillation decay rare-earth orthosilicate scintillation crystal according to claim 8, characterized in that, The strong oxygen vacancy trapping doping source compound includes aluminum oxide and / or a compound containing element M, wherein the compound containing element M includes one or more of oxides, silicides, and carbonates of element M; the strong carrier binding doping source compound includes one or more of oxides, silicides, and carbonates of element N.

11. The ultra-low afterglow fast scintillation decay rare-earth orthosilicate scintillation material according to claim 1, characterized in that, The scintillation material can have its afterglow and scintillation decay performance optimized by air annealing, but after annealing temperatures above 1400°C will cause the afterglow and scintillation decay performance to deteriorate due to the escape of hydrogen ions.

12. The application of the ultra-low afterglow fast scintillation decay rare earth orthosilicate scintillation material according to any one of claims 1 to 6 in any field including high energy physics, nuclear physics, space physics, nuclear medicine imaging diagnosis, industrial non-destructive testing, security inspection, geology and mineral and oil well exploration, and environmental monitoring, especially in the field of single-photon CT (PCCT).

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