Glass scintillator for thermal neutron detection and preparation method thereof

Abstract

The invention discloses a glass scintillator for thermal neutron detection, the glass scintillator is rich in 6Li and 10B element compounds with large neutron capture cross sections, the total mole amount of Li2O and B2O3 can reach up to 80 mol%, the highest content of Li2O is 40 mol%, the neutron capture ability of the glass scintillator is significantly enhanced, and the neutron detection efficiency is further improved. The invention also discloses a preparation method of the glass scintillator, most of trivalent europium in the glass is reduced into divalent europium by constructing a reducing atmosphere, and a proper amount of silicon nitride is supplemented to enhance the reduction effect of the trivalent europium, so that the concentration ratio of the divalent europium is further enhanced, and the glass scintillator is prepared. Or by prolonging the melting time of the lithium borosilicate glass scintillator, the concentration proportion of divalent europium in the glass is further improved, the negative influence of trivalent europium in the glass on neutron detection is reduced, and the efficiency of neutron detection is further improved.

Description

Technical Field

[0001] The invention belongs to the field of luminescent materials, in particular to a divalent europium-activated lithium borosilicate glass scintillator for thermal neutron detection and a preparation method thereof. Background Art

[0002] Scintillating materials are optical functional materials that emit visible light after absorbing high-energy rays. They are combined with various photomultiplier tubes, charge-coupled devices and photodiodes to detect, identify and quantitatively analyze various ionizing radiation and high-energy particles. In recent years, they have been widely used in high-energy physics, nuclear physics, astrophysics, geophysics, industrial flaw detection, medical imaging and safety testing. Scintillators mainly exist in the form of single crystals, glass, transparent ceramics, polymers and various composite materials.

[0003] Generally speaking, neutron detectors mainly include gas detectors, liquid detectors and solid detectors. Gas detectors mainly use gaseous scintillators, such as 3 He or 10 BF3 gas. However, gas scintillators are difficult to promote and apply due to their large size, difficulty in carrying, and expensive gas tubes. In fact, liquid scintillators also have similar shortcomings as gas scintillators, making them difficult to be widely used. Solid scintillators are playing an increasingly important role in the field of neutron detection due to their compact size and portability.

[0004] At present, solid-state detectors are widely used 6 LiF / ZnS:Ag or 10 Composite scintillators such as B2O3 / ZnS:Ag. 6 LiF or 10 B2O3 can enhance the probability of interaction between the scintillator and neutrons, and transfer the energy of the captured neutrons to the high-efficiency ZnS:Ag luminescent body through nuclear reactions. However, this composite scintillating material effectively combines the two materials together through a transparent optical bonding material (adhesive), which has significant shortcomings during use. On the one hand, a large amount of adhesive combining the two powders together will result in 6 LiF or 10 The amount of space occupied by B2O3 is very small, which reduces the probability of neutron capture. On the other hand, the combination of the two powders will cause the emitted light to be scattered through the internal interface and absorbed during the transmission process, which greatly depletes the luminous intensity of the scintillator. These loss mechanisms induce the so-called "thickness limitation" problem: when the thickness of the composite scintillator exceeds its own threshold, the corresponding light output is not enhanced. Therefore, continuous large-volume composite scintillating materials are difficult to put into practical application.

[0005] In order to further solve the limitations of composite scintillators such as light scattering and "thickness limitation", rare earth doped glass scintillator is an ideal solution. Glass scintillator has obvious advantages in many aspects such as high concentration doping, large area preparation, fiber opticization and low cost, and can easily expand its application field. For example, the patent named "Phosphate glasses suitable for neutron detection and fibers utilizing such glasses" discloses a phosphate glass scintillator for neutron detection, but the total content of Li2O and B2O3 components in the disclosed glass formula does not exceed 30 mol%, which is not conducive to enhancing the ability of glass scintillator to capture neutrons. For example, the invention patent with patent publication number CN1903763A and the name "A glass scintillator for thermal neutron detection and its preparation method" discloses a Ce-based scintillator. 3+ The ions are Li2O-Al2O3-SiO2 glass scintillator materials with luminescence centers, but the Li2O content is only 10-13 mol%. For example, the invention patent with the publication number CN200610089209.5 and the name of "a glass scintillator for thermal neutron detection and its preparation method" also discloses a glass scintillator with Ce 3+ The ions are the luminescent center of the Li2O-Al2O3-Sb2O3-SiO2 glass scintillating material, in which the Li2O content is only 13 mol%.

[0006] Obviously, the glass scintillator involved in the above invention patent has a content of Li2O and (or) B2O3, which are closely related to the neutron capture cross section, which is significantly lower than 30 mol%. Increasing the total content of neutron capture-rich elements in the glass scintillator is conducive to enhancing the probability of interaction between neutron rays and glass, which is one of the key issues in improving the efficiency of neutron detection. On the other hand, the divalent europium ions in the glass scintillator have a microsecond decay time, which is three orders of magnitude faster than the corresponding trivalent europium ion decay time, which is conducive to rapid detection. Therefore, the efficient reduction of trivalent europium ions in glass to divalent europium ions in an air atmosphere has important application value for the practical application of neutron detection. Summary of the invention

[0007] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a transparent divalent europium (Eu 2+ ) activates a lithium borosilicate glass scintillator, wherein the glass scintillator is rich in neutrons with a large capture cross section. 6 Li and (or) 10 B, etc., can capture neutron energy through nuclear reactions and transfer it to divalent europium ions (Eu 2+ ), thereby meeting the needs of different detection fields. At the same time, the present invention also provides a preparation method and application of the glass scintillator.

[0008] To achieve the above-mentioned purpose, on the one hand, the present invention provides a glass scintillator for thermal neutron detection, wherein the glass scintillator comprises a glass matrix and divalent europium ions doped therein; the glass matrix is ​​composed of the following components in molar content: Li2O: 0-40mol%, B2O3: 0-65mol%, SiO2: 0-40mol%, Si3N4: 0-10mol%; the molar content of the divalent europium ions in the glass scintillator is 0.01-10mol%.

[0009] The glass scintillator of the present invention, the system composition of the glass matrix can be expressed as: Li2O-B2O3-SiO2-Si3N4. From the molar content of each component of the glass matrix mentioned above, it can be seen that the present invention increases the content of the glass matrix. 6 Li and 10 The total content of B is increased to improve the neutron capture ability, thereby achieving the purpose of high neutron detection efficiency. By reducing most of the trivalent europium in the glass to divalent europium, using divalent europium ions as the luminescence center, and using an appropriate amount of silicon nitride to replace part of the silicon dioxide in the glass matrix to further increase the concentration ratio of divalent europium in the glass, the negative impact of trivalent europium in the glass on neutron detection is reduced, and the efficiency of neutron detection is further improved.

[0010] In the glass scintillator of the present invention, the sum of the molar contents of Li2O, B2O3 and SiO2 in the glass matrix and the sum of the molar content of Si in Si3N4 is 100%.

[0011] Preferably, the glass matrix consists of the following components in molar contents: Li2O: 15-40 mol%, B2O3: 25-60 mol%, SiO2: 5-40 mol%, Si3N4: 0-5 mol%.

[0012] Preferably, the molar content of Si3N4 in the glass matrix is ​​0.1-0.5 mol%. When Si3N4 is used to replace part of the silicon dioxide in the glass matrix, the molar content of Si3N4 is preferably 0.1-0.5 mol%.

[0013] Preferably, the molar content of the divalent europium ions in the glass scintillator is 0.01-5 mol %. More preferably, the molar content of the divalent europium ions in the glass scintillator is 0.025-0.7 mol %.

[0014] Preferably, the glass matrix is ​​composed of the following components in molar content: Li2O: 35mol%, B2O3: 45mol%, SiO2: 19.5-20mol%, Si3N4: 0-0.5mol%; the molar content of the divalent europium ion in the glass scintillator is 0.025-0.7mol%. When the glass matrix is ​​composed of the components in the specific molar amounts, the formula of the glass scintillator can be expressed as: 35Li2O-45B2O3-(20-3y)SiO2-ySi3N4-xEu2O3, and the molar content ranges of x and y in the glass are: x is 0.025-0.7mol%, y is 0-0.5mol%. The luminescent center is Eu 2+ Ions, the glass scintillator has an optical transmittance of more than 80% in the wavelength range of 450-800nm.

[0015] Preferably, in the glass scintillator, the total molar content of Li2O and B2O3 in the glass matrix is ​​80 mol%.

[0016] In a second aspect, the present invention further provides a method for preparing the glass scintillator for thermal neutron detection. To achieve this purpose, the technical solution adopted by the present invention is: a method for preparing the glass scintillator for thermal neutron detection as described above, the method comprising the following steps:

[0017] (1) According to the composition of the glass scintillator, accurately weigh the Li2O raw material, B2O3 raw material, SiO2 raw material, Si3N4 raw material and divalent europium ion raw material, and grind them evenly:

[0018] (2) melting the uniformly ground raw materials in a reducing atmosphere to obtain a uniform glass melt;

[0019] (3) casting the glass melt into a shape, then annealing and cooling to obtain a glass scintillator;

[0020] The melting treatment in step (2) is as follows: firstly melting at a temperature of 1050-1350° C. for 30-300 minutes, then cooling the glass melt to 1050-1150° C. and continuing melting for 5-10 minutes;

[0021] The annealing in step (3) is constant temperature annealing.

[0022] In the preparation method of the glass scintillator of the present invention, the raw materials in step (1) can be ground in, for example, but not limited to, an agate mortar, and the grinding time can be, for example, 10 minutes, which is determined according to the raw materials and the grinding speed, as long as the raw materials are fully ground and uniform. The uniformly ground raw materials can be poured into, for example, but not limited to, an alumina crucible, and then placed in a muffle furnace for melting to obtain a glass melt. Finally, the glass melt is poured into a mold for casting and molding, and after constant temperature precision annealing treatment, a glass scintillator can be obtained.

[0023] The preparation method of the glass scintillator described in the present invention reduces most of the trivalent europium ions in the lithium borosilicate to divalent ones as much as possible by constructing a reducing atmosphere, and further increases the concentration ratio of divalent europium in the glass by replacing 0.1-0.5 mol% SiO2 in the glass with silicon nitride (Si3N4), or by extending the melting time of the lithium borosilicate glass scintillator to further increase the concentration ratio of divalent europium in the glass. Transparent divalent europium-activated lithium borosilicate glass scintillator can be prepared to meet the actual needs of different detection fields.

[0024] Preferably, the Li2O raw material, B2O3 raw material, SiO2 raw material, and Si3N4 raw material include at least one of oxides and carbonates of the corresponding elements. The divalent europium ion raw material includes at least one of europium oxides, halides, carbonates, nitrates, and sulfates. More preferably, the Li2O raw material is lithium carbonate; the B2O3 raw material is at least one of boron oxide and boric acid; the SiO2 raw material is silicon dioxide; the Si3N4 raw material is Si3N4; the divalent europium ion raw material includes at least one of Eu2O3, Eu2SiO5, EuF3, EuCl3, EuBr3, Eu2(CO3)3, Eu(NO3)3, EuPO4, and Eu2(SO4)3. The purity of all raw materials is required to be analytically pure or above.

[0025] Preferably, the reducing atmosphere in step (2) is made of carbon powder. The reducing atmosphere can be made of conventional reducing substances known at present, such as but not limited to carbon powder.

[0026] Preferably, in step (2), the alloy is first melted at a temperature of 1250 to 1350° C. for 30 to 300 minutes.

[0027] Preferably, in step (2), the cooling rate of the glass melt to 1050-1150° C. is 5-10° C. / min.

[0028] Preferably, in the step (3), after the glass melt is formed on a stainless steel mold preheated at a temperature of 300-500° C., it is quickly transferred to a muffle furnace for annealing.

[0029] Preferably, the annealing temperature in step (3) is 300-500°C, and the annealing time is 4-10 hours. More preferably, the annealing temperature in step (3) is 400°C. In the preparation method of the glass scintillator of the present invention, it is necessary to undergo constant temperature precision annealing treatment, and the annealing temperature is 300-500°C, for example, 400°C, and the annealing time is 4-10 hours. After annealing, it is generally cooled naturally to obtain a glass scintillator sample, and then the obtained glass scintillator sample is cut, surface polished with abrasive, etc., to finally obtain a finished glass scintillator.

[0030] Preferably, in the step (1), Si3N4 raw material is weighed according to the molar content of Si3N4 in the glass matrix of 0.1-0.5 mol%, and in the step (2), the melting time is 30-60 minutes at a temperature of 1050-1350°C. More preferably, the melting time is 30-60 minutes at a temperature of 1250-1350°C in the step (2). For example, the melting temperature in the step (2) can be 1250°C, 1300°C, etc.

[0031] Preferably, the amount of Si3N4 raw material added in step (1) is 0, and the melting time in step (2) is 60 to 300 minutes at a temperature of 1050 to 1350°C. More preferably, the melting time in step (2) is 60 to 300 minutes at a temperature of 1250 to 1350°C.

[0032] In the preparation method of the glass scintillator of the present invention, a reducing atmosphere can be constructed by reducing substances, and Si3N4 can be used to replace part of the silicon dioxide in the glass matrix to prepare transparent divalent europium (Eu 2+ ) to activate the lithium borosilicate glass scintillator. Alternatively, a reducing atmosphere composed of reducing substances is introduced, and the melting time at a temperature of 1250 to 1350°C in step (2) is prolonged, which can also achieve the purpose of trivalent europium (Eu 3+ ) is completely reduced to prepare transparent divalent europium (Eu 2+ ) activates the lithium borosilicate glass scintillator.

[0033] The inventors of the present application have found in their research that the glass scintillator prepared by introducing a reducing atmosphere constructed by reducing substances and prolonging the melting time at a temperature of 1250-1350°C in step (2) has a higher luminous intensity than the glass scintillator prepared by replacing part of the silicon dioxide in the glass matrix with Si3N4, and the integrated luminescence is also increased by more than 150%.

[0034] In a third aspect, the present invention also provides the use of the glass scintillator described above in a neutron scintillator screen, a neutron scintillator array, an optical fiber, and an optical fiber panel. The glass scintillator described in the present invention is a transparent divalent europium (Eu 2+ ) activated lithium borosilicate glass scintillator has high luminous intensity and good comprehensive performance, and can be widely used in neutron detection, neutron flight time, medical imaging, radiation detection and non-destructive testing, such as for the preparation of neutron scintillation screens, neutron scintillation arrays, optical fibers and optical fiber panels.

[0035] Finally, the present invention also provides a product containing the glass scintillator as described above, wherein the product is a neutron scintillator screen, a neutron scintillator array, an optical fiber or an optical fiber panel. The neutron scintillator screen, the neutron scintillator array, the optical fiber or the optical fiber panel prepared by using the glass scintillator of the present invention also has a high luminous intensity.

[0036] The glass scintillator of the present invention is rich in neutron capture cross-section 6 Li and 10 The total molar amount of B element compounds, Li2O and B2O3 can be as high as 80 mol%, of which the maximum content of Li2O is 40 mol%, which significantly enhances the neutron capture ability of the glass scintillator and further improves the efficiency of neutron detection.

[0037] The preparation method of the glass scintillator of the present invention reduces most of the trivalent europium in the glass to divalent europium by constructing a reducing atmosphere, and supplements with an appropriate amount of silicon nitride to enhance the reduction effect of the trivalent europium, further enhancing the concentration ratio of the divalent europium, or prolonging the melting time of the lithium borosilicate glass scintillator to further increase the concentration ratio of the divalent europium in the glass, so as to prepare a transparent divalent europium-activated lithium borosilicate glass scintillator, and giving full play to the coordinated reduction effect of the reducing atmosphere and Si3N4 can further increase the concentration ratio of the divalent europium in the lithium borosilicate glass prepared in the air atmosphere, or by giving full play to the reducing atmosphere and prolonging the melting time to further increase the trivalent Eu 3+ Ion reduction to Eu 2+ ions, increase the concentration ratio of divalent europium in lithium borosilicate glass, reduce the negative impact of trivalent europium in glass on neutron detection, further improve the efficiency of neutron detection, and thus meet the actual needs of different detection fields. The preparation method of the present invention is simple and safe, the chemical composition and raw materials are easy to adjust, the size and shape of the prepared glass scintillator are well controllable, and it can be further drawn into optical fiber. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The transmission spectrum of the glass scintillator prepared in Example 10;

[0039] Figure 2The photoluminescence spectra of the glass scintillators prepared in Examples 8-12;

[0040] Figure 3 The photoluminescence spectra of the glass scintillators prepared in Examples 10 and 13-15;

[0041] Figure 4 This is the decay time curve of the glass scintillator prepared in Example 14;

[0042] Figure 5 The photoluminescence spectra of the glass scintillator obtained at different melting times in Example 18;

[0043] Figure 6 This is a comparison chart of the luminescent properties of the glass scintillators prepared in Example 14 and Example 18 at a melting time of 270 minutes. DETAILED DESCRIPTION

[0044] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0045] Examples 1 to 15

[0046] The specific embodiments of the glass scintillator for thermal neutron detection of the present invention are as follows: the glass scintillators of embodiments 1 to 15 are prepared by the same method except for the different contents of components.

[0047] The components and contents of the glass scintillators described in Examples 1 to 15 are shown in Table 1 below. The preparation methods of the glass scintillators described in Examples 1 to 15 are:

[0048] (1) According to the composition of each group of glass scintillators in Table 1, accurately weigh the Li2O raw material, B2O3 raw material, SiO2 raw material, Si3N4 raw material and divalent europium ion raw material, wherein the Li2O raw material is lithium carbonate, the B2O3 raw material is boron oxide, the SiO2 raw material is silicon dioxide, the Si3N4 raw material is Si3N4, and the divalent europium ion raw material is Eu2O3, and fully grind the raw materials in an agate mortar for 10 minutes;

[0049] (2) melting the raw materials uniformly ground in step (1) in a reducing atmosphere pre-formed with carbon powder, wherein the melting process is carried out in a muffle furnace at a melting temperature of 1300° C. After melting for 30 minutes, the temperature is reduced to 1050° C. at a rate of 10° C. / min, and then the temperature is continued to be melted at 1050° C. for 5 minutes to obtain a uniform glass melt;

[0050] (3) casting the glass melt into a stainless steel mold preheated at 400° C., and quickly placing the formed glass in a muffle furnace at 400° C. for annealing for 4-10 hours, and then cooling it naturally to obtain a glass scintillator sample;

[0051] (4) Cut the glass scintillator sample into 10×10×2 mm 3 The glass scintillators of each embodiment are obtained by forming the glass scintillators into regular shapes and grinding and polishing the surfaces.

[0052] Table 1 Glass scintillator composition and content of Examples 1 to 15

[0053]

[0054]

[0055] In the glass matrix of each embodiment, the sum of the molar contents of Li2O, B2O3 and SiO2 and the sum of the molar content of Si in Si3N4 is 100%.

[0056] Effect Example 1

[0057] Performance test of the glass scintillator of the present invention

[0058] The transmission spectrum of the glass scintillator prepared in Example 10 was tested using a spectrophotometer (Lambda 750S, PerkinElmer, USA). The test results are shown in the attached figure. Figure 1 shown.

[0059] From the attached Figure 1 It can be seen that the optical transmittance of the glass scintillator of the present invention exceeds 90% in the wavelength range of 450-800 nm, which is of great significance for improving the light output of the glass scintillator.

[0060] The photoluminescence spectra of the glass scintillators prepared in Examples 8 to 12 were tested by using a fluorescence spectrometer (FLS980 spectrometer from Edinburgh Instruments, ExSlit 0.6 nm, EmSlit 0.6 nm) under ultraviolet light 394 nm excitation. The results are shown in the attached figure. Figure 2 shown.

[0061] From the attached Figure 2A broad peak emission of 400-700 nm can be observed, and the broadband emission peak belongs to the allowed transition of divalent europium ions 5d-4f. Under the same experimental conditions, the best emission intensity is exhibited when the europium ion doping concentration is 0.3 mol%. On the other hand, as the europium ion concentration increases, the broadband emission peak of the europium-activated lithium borosilicate glass scintillator undergoes an obvious red shift, that is, from 450 nm (Example 8), 455 nm (Example 9), 460 nm (Example 10), gradually red shifted to 464 nm (Example 11) and 468 nm (Example 12).

[0062] In order to study the effect of replacing part of SiO2 in the glass component with an appropriate amount of Si3N4, the inventors of the present application further tested the photoluminescence spectra of the glass scintillators prepared in Examples 10 and 1-15 under 394nm excitation. The testing method was the same as that of Examples 8 to 12 above. The test results are shown in the attached figure. Figure 3 shown.

[0063] By the attached Figure 3 It can be seen that the broad peak emission at 400-700nm can still be observed from the emission spectrum. Figure 2 The emission spectra of the glass scintillator without Si3N4 (Examples 8-12) and the emission spectra of the glass scintillator with Si3N4 added to Eu 3+ The emission peak intensity at 614nm is significantly reduced.

[0064] To better illustrate Eu 3+ The inventors of the present application collected the luminescence decay curve of the glass scintillator prepared in Example 14 (excitation wavelength 394nm, emission wavelength 460nm), and the results are shown in the attached figure. Figure 4 shown.

[0065] From the attached Figure 4 The decay curve fitting results in a lifetime of 2240.68 nanoseconds, which is a typical decay time characteristic of divalent europium. 2+ Excellent reduction effect of ions.

[0066] Embodiments 16 to 20

[0067] Examples 16 to 20 mainly examine the performance changes of the glass scintillator prepared by extending the melting time instead of replacing part of SiO2 in the glass component with Si3N4.

[0068] The composition and content of the glass scintillator in Examples 16 to 20 are shown in Table 2 below.

[0069] Table 2 Composition and content of the glass scintillator described in Examples 16 to 20

[0070]

[0071] The preparation methods of the glass scintillators described in Examples 16 to 20 are all as follows:

[0072] (1) According to the composition of each group of glass scintillators in Table 2, accurately weigh the Li2O raw material, B2O3 raw material, SiO2 raw material and divalent europium ion raw material, wherein the Li2O raw material is lithium carbonate, the B2O3 raw material is boron oxide, the SiO2 raw material is silicon dioxide, and the divalent europium ion raw material is Eu2O3, and grind the raw materials in an agate mortar for 10 minutes;

[0073] (2) melting the raw materials ground uniformly in step (1) in a reducing atmosphere pre-formed with carbon powder, wherein the melting process is carried out in a muffle furnace, the melting temperature is 1300° C., the melting times are 30 minutes, 90 minutes, 150 minutes, 210 minutes and 270 minutes respectively, and then the temperature is reduced to 1050° C. at a rate of 10° C. / min, and then the melting is continued at 1050° C. for 5 minutes to obtain a uniform glass melt;

[0074] (3) casting the glass melt into a stainless steel mold preheated at 400° C., and quickly placing the formed glass in a muffle furnace at 400° C. for annealing for 4-10 hours, and then cooling it naturally to obtain a glass scintillator sample;

[0075] (4) Cut the glass scintillator sample into 10×10×2 mm 3 After the glass scintillators with different melting times in various embodiments are formed into regular shapes and the surfaces are ground and polished, they are obtained.

[0076] Effect Example 2

[0077] In order to investigate the influence of different melting times on the performance of the prepared glass scintillator, this effect example takes the composition and content of the glass scintillator of Example 18 as an example, and tests the performance of the glass scintillators prepared by using different melting times.

[0078] The photoluminescence spectra of the glass scintillators prepared at different melting times in Test Example 18 under 394 nm excitation are shown in the attached figure. Figure 5 shown.

[0079] By the attached Figure 5 It can be seen that the Eu at 400-700nm 2+ The broad peak emission intensity increases significantly with the extension of melting time, and is attributed to Eu 3+ The emission peak intensity at 614nm has completely disappeared, which clearly shows that prolonging the melting time can achieve complete reduction of trivalent europium ions and further improve the luminescence intensity of divalent europium ions.

[0080] In addition, the performance of the glass scintillator prepared by melting for 270 minutes in Example 18 was compared with that of the glass scintillator in Example 14. The emission spectra of the two when excited at 394 nm are shown in the attached figure. Figure 6 shown.

[0081] By the attached Figure 6 It can be seen that the method of delaying the melting time is more beneficial to Eu than introducing Si3N4 reducing agent. 2+ The luminous intensity of the activated lithium borosilicate glass scintillator increased by 152.04%. This also proves that by constructing a reducing atmosphere and appropriately extending the melting time, it is more helpful to increase the Eu in the glass. 3+ The reducing power of ions.

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A glass scintillator for thermal neutron detection, characterized in that: The glass scintillator comprises a glass matrix and divalent europium ions doped therein; The glass matrix is ​​composed of the following components in molar content: Li2O: 0-40mol%, B2O3: 0-65mol%, SiO2: 0-40mol%, Si3N4: 0-10mol%; The molar content of the divalent europium ions in the glass scintillator is 0.01-10 mol %.

2. The glass scintillator for thermal neutron detection according to claim 1, characterized in that: The glass matrix is ​​composed of the following components in molar contents: Li2O: 15-40 mol%, B2O3: 25-60 mol%, SiO2: 5-40 mol%, Si3N4: 0-5 mol%.

3. The glass scintillator for thermal neutron detection according to claim 1 or 2, characterized in that: The molar content of the divalent europium ions in the glass scintillator is 0.01-5 mol %.

4. The glass scintillator for thermal neutron detection according to claim 4, characterized in that: The glass matrix is ​​composed of the following components in molar content: Li2O: 35 mol%, B2O3: 45 mol%, SiO2: 19.5-20 mol%, Si3N4: 0-0.5 mol%; the molar content of the divalent europium ions in the glass scintillator is 0.025-0.7 mol%.

5. A method for preparing a glass scintillator for thermal neutron detection according to any one of claims 1 to 4, characterized in that: The method comprises the following steps: (1) According to the composition of the glass scintillator, accurately weigh the Li2O raw material, B2O3 raw material, SiO2 raw material, Si3N4 raw material and divalent europium ion raw material, and grind them evenly: (2) melting the uniformly ground raw materials in a reducing atmosphere to obtain a uniform glass melt; (3) casting the glass melt into a shape, then annealing and cooling to obtain a glass scintillator; The melting treatment in step (2) is as follows: firstly melting at a temperature of 1050-1350° C. for 30-300 minutes, then cooling the glass melt to 1050-1150° C. and continuing melting for 5-10 minutes; The annealing in step (3) is constant temperature annealing.

6. The method for preparing a glass scintillator for thermal neutron detection according to claim 5, characterized in that: The Li2O raw material, B2O3 raw material, SiO2 raw material, and Si3N4 raw material include at least one of oxides and carbonates of the corresponding elements; And / or, the divalent europium ion raw material includes at least one of europium oxide, halide, carbonate, nitrate and sulfate.

7. The method for preparing a glass scintillator for thermal neutron detection according to claim 5 or 6, characterized in that: The Li2O raw material is lithium carbonate; And / or, the B2O3 raw material is at least one of boron oxide and boric acid; And / or, the SiO2 raw material is silicon dioxide; And / or, the Si3N4 raw material is Si3N4; And / or, the divalent europium ion raw material includes at least one of Eu2O3, Eu2SiO5, EuF3, EuCl3, EuBr3, Eu2(CO3)3, Eu(NO3)3, EuPO4, and Eu2(SO4)3; And / or, the reducing atmosphere in step (2) is constructed of carbon powder; And / or, in the step (2), the cooling rate of the glass melt to 1050-1150° C. is 5-10° C. / min; And / or, the annealing temperature in step (3) is 300-500° C., and the annealing time is 4-10 hours.

8. The method for preparing a glass scintillator for thermal neutron detection according to claim 5, characterized in that: In the step (1), Si3N4 raw material is weighed according to the molar content of Si3N4 in the glass matrix of 0.1-0.5 mol%, and in the step (2), the melting time is 30-60 minutes at a temperature of 1050-1350°C; Alternatively, the amount of Si3N4 raw material added in step (1) is 0, and the melting time in step (2) is 60 to 300 minutes at a temperature of 1050 to 1350°C.

9. Use of the glass scintillator according to any one of claims 1 to 4 in a neutron scintillator screen, a neutron scintillator array, an optical fiber and an optical fiber panel.

10. A product containing the glass scintillator according to any one of claims 1 to 4, characterized in that: The product is a neutron scintillation screen, a neutron scintillation array, an optical fiber or an optical fiber panel.

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