Rare earth halide X-ray scintillator film with high resolution and fast attenuation and preparation method of rare earth halide X-ray scintillator film

Abstract

The invention provides a high-resolution and fast-attenuation rare earth halide X-ray scintillator film and a preparation method thereof, and relates to the technical field of inorganic scintillating materials. The preparation method of the X-ray scintillator film comprises the following steps: mixing cesium bromide, cerium bromide and water to obtain a precursor solution, and drying the precursor solution to obtain precursor powder; annealing the precursor powder to obtain rare earth halide X-ray scintillator powder; and evaporating the rare earth halide X-ray scintillator powder to the surface of the substrate material to obtain the X-ray scintillator film. The method for preparing the X-ray scintillator powder is simple, does not involve long-time high-temperature calcination, and is beneficial to large-scale synthesis of the scintillator powder; according to the invention, the film is prepared by vacuum evaporation, no toxic or difficult-to-recycle organic solvent is needed in the whole process, and the final product has a self-organized pixelated crystal structure and also has the advantages of large area, purity, flatness and transparency.

Description

Technical Field

[0001] The invention relates to the technical field of inorganic scintillating materials, and in particular to a high-resolution, fast-attenuation rare earth halide X-ray scintillator film and a preparation method thereof. Background Art

[0002] X-rays are electromagnetic waves with short wavelengths (1pm to 10nm) and high energy (124eV to 1.24MeV). They are crucial in key areas such as basic research, deep space exploration, medical imaging, and security inspections. An ideal X-ray detector needs to have the following performance evaluation indicators: fast-decaying fluorescence lifetime, high spatial resolution, and high light yield. In addition, given that X-ray photons mainly present particle characteristics, their difficult-to-modulate properties need to be fully considered in actual detection applications to meet the needs of large-area detection devices. At present, X-ray detectors based on traditional semiconductor materials have been widely used, such as YAG:Ce, LYSO:Ce, GOS, CsI:Tl, etc. However, with the continuous expansion of service environments and the sharp increase in detection needs, current commercial scintillators are facing the dilemma of being unable to meet increasingly stringent performance challenges. For example, the light yield of YAG:Ce and GOS is low, and the fluorescence lifetime of CsI:Tl and LYSO:Ce decays too slowly. Furthermore, the high spatial resolution required for nondestructive testing of high-precision electronic components is difficult to achieve, and the large-area devices required for imaging large-volume objects are also difficult to meet.

[0003] In recent years, rare earth halide materials have stood out due to their advantages such as adjustable optical properties, high light yield, rich crystal structure and flexible synthesis and preparation process brought by abundant energy level transitions. In particular, their inherent high atomic number and high-quality elements ensure their good X-ray absorption, and the related scintillators show fast decay rate, excellent spectral characteristics and excellent imaging detection performance. They are considered to be a new generation of efficient and feasible scintillator materials. However, there are still some thorny problems to be solved in this type of material, which can be classified into the following two aspects: 1. The high cost of single crystal scintillator preparation hinders its further application. High-performance scintillator single crystals show excellent performance in X-ray detection, but a class of single crystal preparation methods represented by the Bridgman method has a high threshold for use, such as dependence on high-purity chemicals, high time and economic costs, and susceptibility to interference from the external environment and human factors. In addition, the inherent small area and poor mechanical properties of single crystal materials have aggravated the difficulty of its device process. 2. The conditions for achieving self-organized pixelation crystallization inside the film are harsh. At present, wet chemical methods represented by the scraping method are the mainstream preparation methods in many rare earth halide scintillator thin film studies. However, in the process of film formation and crystallization, this type of method is often accompanied by the surface solvent escaping faster than the deep layer, resulting in solvent retention inside the film, and then forming a large number of holes and cracks, which deteriorates the resolution and light yield of the final scintillator device. Therefore, it is particularly urgent to develop a simple and efficient preparation method to achieve efficient production of fast-decaying rare earth halide scintillator materials while realizing the preparation of high-resolution large-area thin films with controllable crystallization. Summary of the invention

[0004] The purpose of the present invention is to provide a high-resolution, fast-attenuation rare earth halide X-ray scintillator film and a preparation method thereof, so as to solve the problems of high preparation cost, small area, poor mechanical properties of existing single crystal scintillator materials and poor film preparation effect using wet chemical method.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a method for preparing a high-resolution, fast-attenuation rare earth halide X-ray scintillator film, comprising the following steps:

[0007] 1) mixing cesium bromide, cerium bromide and water to obtain a precursor solution, and drying the precursor solution to obtain a precursor powder;

[0008] 2) annealing the precursor powder to obtain rare earth halide X-ray scintillator powder;

[0009] 3) Evaporating rare earth halide X-ray scintillator powder onto the surface of a substrate material to obtain a high-resolution, fast-attenuation rare earth halide X-ray scintillator film.

[0010] Preferably, the mass volume ratio of cesium bromide, cerium bromide and water in step 1) is 5.746-7.022 g: 3.798 g: 15-25 mL;

[0011] The drying temperature is 70-105°C.

[0012] Preferably, the annealing temperature in step 2) is 150-300° C., and the annealing time is 10-60 min.

[0013] Preferably, the vacuum degree of the environment at the beginning of the evaporation in step 3) is 2×10 -4 ~2×10 -3 pa.

[0014] Preferably, the rotation speed of the substrate material during the evaporation process in step 3) is 0 to 25 r / s.

[0015] Preferably, the deposition rate of the rare earth halide X-ray scintillator powder on the surface of the substrate material in step 3) is

[0016] Preferably, the substrate material in step 3) is a pre-treated glass substrate;

[0017] The pretreatment method is to sequentially wash the glass substrate with water and alcohol, and then bombard the glass substrate with oxygen plasma for 5 to 7 minutes.

[0018] The present invention also provides a high-resolution, fast-decaying rare earth halide X-ray scintillator film prepared by the above preparation method, wherein the thickness of the high-resolution, fast-decaying rare earth halide X-ray scintillator film is 2 to 13 μm.

[0019] The present invention has at least the following beneficial effects:

[0020] 1. The preparation method of the rare earth halide scintillator powder of the present invention can be achieved by a simple rotary evaporation method, which is simple to operate, does not involve long-term high-temperature calcination, and takes a short preparation time;

[0021] 2. The present invention can realize the mass synthesis of scintillator powder and the product has high purity;

[0022] 3. The film preparation method of the present invention is realized by vacuum evaporation method, and no toxic or difficult to recycle organic solvents are used in the whole process;

[0023] 4. The scintillator film obtained by the present invention has a crystal structure of self-organized pixelated crystallization, and has the advantages of large area, purity, flatness and transparency;

[0024] 5. The scintillator prepared by the present invention exhibits excellent luminescence properties, with an ultrafast decay of about 15ns and a high spatial resolution of 26lp / mm. At the same time, its light yield (~14600ph / MeV) is better than the commonly used BGO (8000~10000ph / MeV) scintillator on the market. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 X-ray powder diffraction (XRD) patterns of the rare earth halide X-ray scintillator powder prepared in Example 2 and the rare earth halide X-ray scintillator film prepared in Example 8;

[0026] Figure 2 This is a microscopic morphology of the rare earth halide X-ray scintillator film prepared in Example 8. Figure 2 a in the figure is the morphology of rare earth halide X-ray scintillator film under scanning electron microscope (SEM). Figure 2 b is a cross-sectional photograph of a rare earth halide X-ray scintillator film;

[0027] Figure 3 This is an energy dispersive X-ray (EDX) analysis diagram of the rare earth halide X-ray scintillator film prepared in Example 8;

[0028] Figure 4 This is a time-resolved photoluminescence (TRPL) image of the rare earth halide X-ray scintillator powder prepared in Example 2;

[0029] Figure 5 This is the photoluminescence (PL) spectrum of the rare earth halide X-ray scintillator film prepared in Example 8;

[0030] Figure 6 The radioluminescence (RL) spectrum of the rare earth halide X-ray scintillator film prepared in Example 8 under X-ray irradiation;

[0031] Figure 7 a in the figure is the modulation transfer function (MTF) curve of the rare earth halide X-ray scintillator film prepared in Example 8 in the X-ray imaging application. Figure 7 b in the figure is the imaging line pair card photo;

[0032] Figure 8 The optical photograph of the rare earth halide X-ray scintillator film prepared in Example 8 and the X-ray imaging diagram of the object are shown in FIG. Figure 8 a in the figure is an optical photograph of a rare earth halide X-ray scintillator film. Figure 8 Figures b, c, and d are photos of X-ray imaging of objects of different shapes using rare earth halide X-ray scintillator films. DETAILED DESCRIPTION

[0033] The present invention provides a method for preparing a high-resolution, fast-attenuation rare earth halide X-ray scintillator film, comprising the following steps:

[0034] 1) mixing cesium bromide, cerium bromide and water to obtain a precursor solution, and drying the precursor solution to obtain a precursor powder;

[0035] 2) annealing the precursor powder to obtain rare earth halide X-ray scintillator powder;

[0036] 3) Evaporating rare earth halide X-ray scintillator powder onto the surface of a substrate material to obtain a high-resolution, fast-attenuation rare earth halide X-ray scintillator film.

[0037] In the present invention, the mass volume ratio of cesium bromide, cerium bromide and water in step 1) is 5.746-7.022 g: 3.798 g: 15-25 mL, preferably 6.065-6.704 g: 3.798 g: 17-23 mL, further preferably 6.257-6.512 g: 3.798 g: 19-21 mL, and more preferably 6.384 g: 3.798 g: 20 mL.

[0038] In the present invention, the drying temperature is 70 to 105°C, preferably 80 to 100°C, more preferably 80 to 95°C, and even more preferably 90°C.

[0039] In the present invention, the drying method is preferably to evaporate the solvent using a rotary evaporator. This is because simple heating evaporation will lead to oxidation of Br ions, resulting in poor purity of the final powder, and a slow evaporation rate. Uncontrollable impurities may accidentally enter during a long evaporation process. The rotary evaporation method can provide a clean vacuum environment and the evaporation process is rapid.

[0040] In the present invention, the annealing temperature in step 2) is 150-300°C, preferably 170-250°C, more preferably 180-220°C, and more preferably 200°C; the annealing time is 10-60min, preferably 20-45min, more preferably 25-35min, and more preferably 30min.

[0041] In the present invention, the vacuum degree of the environment at the beginning of the evaporation in step 3) is 2×10 -4 ~2×10 -3 pa, preferably 3×10 -4 ~8×10 -4 pa, more preferably 4×10 -4 ~6×10 -4 pa, more preferably 5×10 -4 pa.

[0042] In the present invention, the rotation speed of the substrate material during the evaporation process in step 3) is 0 to 25 r / s, preferably 5 to 20 r / s, more preferably 8 to 15 r / s and even more preferably 10 r / s.

[0043] In the present invention, the deposition rate of the rare earth halide X-ray scintillator powder on the surface of the substrate material in step 3) is Preferably More preferably More preferably

[0044] In the present invention, a vacuum evaporator is used to evaporate rare earth halide X-ray scintillator powder onto the surface of a substrate material to obtain a target scintillator film. The heat of the vacuum evaporator is indirectly controlled by the current between electrodes, which comes from the ohmic heat generated by the tungsten boat containing the plating material and the electrodes at both ends. The temperature is indirectly controlled by the current, and the evaporation rate is indirectly controlled by the temperature. During the evaporation process, as the plating material decreases, the resistance of the evaporation system changes (decreases), so the current needs to be slowly adjusted (from 140A to 200A) as the evaporation proceeds, and the frequency and amplitude of the adjustment are fed back by the evaporation rate to ensure that the deposition rate of the X-ray scintillator powder on the surface of the substrate material remains unchanged.

[0045] The substrate material in step 3) is a pre-treated glass substrate;

[0046] The pretreatment method is to ultrasonically clean the glass substrate in deionized water and anhydrous ethanol for 15 minutes, and then bombard the glass substrate with oxygen plasma for 5 to 7 minutes, preferably 5.5 to 6.5 minutes, and more preferably 6 minutes.

[0047] In the present invention, the substrate material needs to be heated to 150-250°C, preferably 170-220°C, and more preferably 200°C before evaporation.

[0048] The present invention also provides a high-resolution, fast-attenuation rare earth halide X-ray scintillator film prepared by the above preparation method, wherein the thickness of the high-resolution, fast-attenuation rare earth halide X-ray scintillator film is 2 to 13 μm, preferably 5 to 9 μm, and more preferably 7 μm.

[0049] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0050] Example 1

[0051] Weigh 5.746g CsBr and 3.798g CeBr3 To a 100ml round-bottom flask, then add 20ml of deionized water and stir thoroughly at room temperature for 24 hours to obtain a colorless, clear and transparent precursor solution. The round-bottom flask containing the precursor solution is then continuously rotary evaporated at 90°C. As the evaporation process proceeds, the white product powder gradually crystallizes and precipitates. After the solvent is basically evaporated and the powder is firmly attached to the wall, the powder is transferred to a reagent bottle and dried in a vacuum drying oven at 60°C for 24 hours to obtain a precursor powder. Subsequently, the precursor powder is annealed on a 200°C hot plate for 30 minutes to obtain the desired rare earth halide X-ray scintillator powder with a purity of 77%.

[0052] Example 2

[0053] Accurately weigh 6.384g CsBr and 3.798g CeBr 3 To a 100ml round-bottom flask, then add 20ml of deionized water and stir thoroughly at room temperature for 24 hours to obtain a colorless, clear and transparent precursor solution. The round-bottom flask containing the precursor solution is then continuously rotary evaporated at 90°C. As the evaporation process proceeds, the white product powder gradually crystallizes and precipitates. After the solvent is basically evaporated and the powder is firmly attached to the wall, the powder is transferred to a reagent bottle and dried in a vacuum drying oven at 60°C for 24 hours to obtain a precursor powder. Subsequently, the precursor powder is annealed on a 200°C hot plate for 30 minutes to obtain the desired rare earth halide X-ray scintillator powder, recorded as Cs 3 Bc 6 , the purity of the rare earth halide X-ray scintillator powder is 97%.

[0054] Example 3

[0055] Accurately weigh 7.022g CsBr and 3.798g CeBr 3 To a 100ml round-bottom flask, then add 20ml of deionized water and stir thoroughly at room temperature for 24 hours to obtain a colorless, clear and transparent precursor solution. The round-bottom flask containing the precursor solution is then continuously rotary evaporated at 90°C. As the evaporation process proceeds, the white product powder gradually crystallizes and precipitates. After the solvent is basically evaporated and the powder is firmly attached to the wall, the powder is transferred to a reagent bottle and dried in a vacuum drying oven at 60°C for 24 hours to obtain a precursor powder. Subsequently, the powder is annealed on a 200°C hot plate for 30 minutes to obtain the desired rare earth halide X-ray scintillator powder with a purity of 85%.

[0056] Example 4

[0057] Weigh 5.00g Cs 3 Bc 6In the tungsten evaporation boat of the vacuum evaporator, a glass substrate that had been ultrasonically cleaned with deionized water and anhydrous ethanol for 15 minutes at room temperature and bombarded with oxygen plasma for 5 minutes was fixed on the substrate holder, rotated at a speed of 10 r / s, and heated to 150°C. When the vacuum degree of the vacuum chamber reached 5×10 -4 After pa, the scintillator coating powder is slowly heated until it melts and evaporates. The deposition rate on the film thickness detector is regulated by adjusting the heating power. Continue evaporation to a target thickness of 7 μm. Then stop evaporation immediately and allow the film to cool to 50°C in the furnace to obtain a rare earth halide X-ray scintillator film. After testing, the light yield of the film is 12740 ph / MeV and the spatial resolution is 21.3 lp / mm.

[0058] Example 5

[0059] Weigh 5.00g Cs 3 Bc 6 In the tungsten evaporation boat of the vacuum evaporator, a glass substrate that had been ultrasonically cleaned with deionized water and anhydrous ethanol for 15 minutes at room temperature and bombarded with oxygen plasma for 5 minutes was fixed on the substrate holder, the substrate was rotated at a speed of 10 r / s, and the substrate was heated to 200°C. When the vacuum degree of the vacuum chamber reached 5×10 -4 After pa, the scintillator coating powder is slowly heated until it melts and evaporates. The deposition rate on the film thickness detector is regulated by adjusting the heating power. Continue evaporation to a target thickness of 7 μm. Then stop evaporation immediately and allow the film to cool to 50°C in the furnace to obtain the target rare earth halide X-ray scintillator film. After testing, the light yield of the film is 14600 ph / MeV and the spatial resolution is 26.4 lp / mm.

[0060] Example 6

[0061] Weigh 5.00g Cs 3 Bc 6 In the tungsten evaporation boat of the vacuum evaporator, a glass substrate that had been ultrasonically cleaned with deionized water and anhydrous ethanol for 15 minutes at room temperature and bombarded with oxygen plasma for 5 minutes was fixed on the substrate holder, the substrate was rotated at a speed of 10 r / s, and the substrate was heated to 250°C. When the vacuum degree of the vacuum chamber reached 5×10 -4 After pa, the scintillator coating powder is slowly heated until it melts and evaporates. The deposition rate on the film thickness detector is regulated by adjusting the heating power. Continue evaporation to a target thickness of 7 μm. Then stop evaporation immediately and allow the film to cool to 50°C in the furnace to obtain a rare earth halide X-ray scintillator film. After testing, the light yield of the film is 11460 ph / MeV and the spatial resolution is 18.5 lp / mm.

[0062] When the substrate temperature is 200°C, the obtained film has the highest mechanical strength, the lowest tendency to fall off, and the best density. During the X-ray imaging process, the films prepared in Examples 4 and 6 will slowly peel off and fall off from the substrate, while the film prepared in Example 5 is the least likely to detach from the substrate and shows the least pinholes and cracks in the SEM test.

[0063] Example 7

[0064] Weigh 5.00g Cs 3 Bc 6 In the tungsten evaporation boat of the vacuum evaporator, a glass substrate that had been ultrasonically cleaned with deionized water and anhydrous ethanol for 15 minutes at room temperature and bombarded with oxygen plasma for 5 minutes was fixed on the substrate holder, the substrate was rotated at a speed of 10 r / s, and the substrate was heated to 200°C. When the vacuum degree of the vacuum chamber reached 5×10 -4 After pa, the scintillator coating powder is slowly heated until it melts and evaporates. The deposition rate on the film thickness detector is regulated by adjusting the heating power. Continue evaporation to a target thickness of 7 μm. Then stop evaporation immediately and allow the film to cool to 50°C in the furnace to obtain a rare earth halide X-ray scintillator film. After testing, the light yield of the film is 13320 ph / MeV and the spatial resolution is 25.2 lp / mm.

[0065] Example 8

[0066] Weigh 5.00g Cs 3 Bc 6 In the tungsten evaporation boat of the vacuum evaporator, a glass substrate that had been ultrasonically cleaned with deionized water and anhydrous ethanol for 15 minutes at room temperature and bombarded with oxygen plasma for 5 minutes was fixed on the substrate holder, the substrate was rotated at a speed of 10 r / s, and the substrate was heated to 200°C. When the vacuum degree of the vacuum chamber reached 5×10 -4 After pa, the scintillator coating powder is slowly heated until it melts and evaporates. The deposition rate on the film thickness detector is regulated by adjusting the heating power. Continue evaporation to the target thickness of 7 μm. Then stop evaporation immediately and let the film cool to 50°C in the furnace to obtain the target rare earth halide X-ray scintillator film. After testing, the light yield of the film is about 14600ph / MeV and the spatial resolution is 26.4lp / mm, recorded as Cs 3 Bc 6 Film.

[0067] Example 9

[0068] Weigh 5.00g Cs 3 Bc 6In the tungsten evaporation boat of the vacuum evaporator, a glass substrate that had been ultrasonically cleaned with deionized water and anhydrous ethanol for 15 minutes at room temperature and bombarded with oxygen plasma for 5 minutes was fixed on the substrate holder, the substrate was rotated at a speed of 10 r / s, and the substrate was heated to 200°C. When the vacuum degree of the vacuum chamber reached 5×10 -4 After pa, the scintillator coating powder is slowly heated until it melts and evaporates. The deposition rate on the film thickness detector is regulated by adjusting the heating power. Continue evaporation to a target thickness of 7 μm. Then stop evaporation immediately and allow the film to cool to 50°C in the furnace to obtain a rare earth halide X-ray scintillator film. According to the test, the light yield of the film is about 11800 ph / MeV and the spatial resolution is 17.7 lp / mm.

[0069] Example 10

[0070] Weigh 5.00g Cs 3 Bc 6 In the tungsten evaporation boat of the vacuum evaporator, a glass substrate that had been ultrasonically cleaned with deionized water and anhydrous ethanol for 15 minutes at room temperature and bombarded with oxygen plasma for 5 minutes was fixed on the substrate holder, the substrate was rotated at a speed of 10 r / s, and the substrate was heated to 200°C. When the vacuum degree of the vacuum chamber reached 5×10 -4 After pa, the scintillator coating powder is slowly heated until it melts and evaporates. The deposition rate on the film thickness detector is regulated by adjusting the heating power. Continue evaporation to a target thickness of 7 μm. Then stop evaporation immediately and allow the film to cool to 50°C in the furnace to obtain a rare earth halide X-ray scintillator film. According to the test, the light yield of the film is about 9830 ph / MeV and the spatial resolution is 13.7 lp / mm.

[0071] Embodiment 11

[0072] 5.00 g of the scintillator powder obtained in Example 1 was weighed and placed in a tungsten boat of a vacuum evaporator. A glass substrate that had been ultrasonically cleaned with deionized water and anhydrous ethanol for 15 minutes at room temperature and bombarded with oxygen plasma for 5 minutes was fixed on a substrate holder. The substrate was rotated at a speed of 10 r / s and heated to 200°C. The vacuum degree of the vacuum chamber reached 5×10 -4 After pa, the scintillator coating powder is slowly heated until it melts and evaporates. The deposition rate on the film thickness detector is regulated by adjusting the heating power. Continue evaporation to a target thickness of 7 μm. Then stop evaporation immediately and allow the film to cool to 50°C in the furnace to obtain a rare earth halide X-ray scintillator film. According to the test, the light yield of the film is about 15240 ph / MeV and the spatial resolution is about 11.2 lp / mm.

[0073] Example 12

[0074] 5.00 g of the scintillator powder obtained in Example 3 was weighed and placed in a tungsten boat of a vacuum evaporator. A glass substrate that had been ultrasonically cleaned with deionized water and anhydrous ethanol for 15 minutes at room temperature and bombarded with oxygen plasma for 5 minutes was fixed on a substrate holder. The substrate was rotated at a speed of 10 r / s and heated to 200°C. The vacuum degree of the vacuum chamber reached 5×10 -4 After pa, the scintillator coating powder is slowly heated until it melts and evaporates. The deposition rate on the film thickness detector is regulated by adjusting the heating power. Continue evaporation to a target thickness of 7 μm. Then stop evaporation immediately and allow the film to cool to 50°C in the furnace to obtain a rare earth halide X-ray scintillator film. According to the test, the light yield of the film is about 10750 ph / MeV and the spatial resolution is about 17.3 lp / mm.

[0075] Figure 1 These are X-ray powder diffraction (XRD) diagrams of the rare earth halide X-ray scintillator powder prepared in Example 2 and the rare earth halide X-ray scintillator film prepared in Example 8. It can be seen from the diagram that the samples exhibit good crystallinity and high phase purity.

[0076] Figure 2 This is a microscopic morphology of the rare earth halide X-ray scintillator film prepared in Example 8. Figure 2 a in the figure is the morphology of rare earth halide X-ray scintillator film under scanning electron microscope (SEM). Figure 2 Figure b is a cross-sectional photograph of a rare earth halide X-ray scintillator film, from which it can be seen that the film exhibits a self-organized pixelated crystal structure, with basically no holes and cracks, and has a high degree of purity.

[0077] Figure 3 This is an energy dispersive X-ray (EDX) analysis diagram of the rare earth halide X-ray scintillator film prepared in Example 8. It can be seen that the Cs, Ce and Br elements are evenly distributed.

[0078] Figure 4 This is a time-resolved photoluminescence (TRPL) image of the rare earth halide X-ray scintillator powder prepared in Example 2. The light decay time of this sample is extremely short, only about 15 ns.

[0079] Figure 5 The photoluminescence (PL) spectrum of the rare earth halide X-ray scintillator film prepared in Example 8. The excitation wavelength of the sample is about 350nm, and the emission spectrum shows a double peak emission, which is 395nm and 430nm, corresponding to the 5d orbital of the excited state to the ground state. 2 F 5 / 2 and 2 F 7 / 2 The transition glows.

[0080] Figure 6 This is the radioluminescence (RL) spectrum of the rare earth halide X-ray scintillator film prepared in Example 8 under X-ray irradiation. The light yield of the film is 14600 ph / MeV.

[0081] Figure 7 a in the figure is the modulation transfer function (MTF) curve of the rare earth halide X-ray scintillator film prepared in Example 8 in the X-ray imaging application. Figure 7 b in the figure is the imaging line pair card photo. Figure 7 It can be seen that the theoretical spatial resolution of the scintillator is calculated to be 26.4 line pairs per millimeter (lp / mm). The actual line pair card imaging photos also show that in the area where the resolution is close to 20lp / mm, the image remains resolvable.

[0082] Figure 8 The optical photograph of the rare earth halide X-ray scintillator film prepared in Example 8 and the X-ray imaging diagram of the object are shown in FIG. Figure 8 a in the figure is an optical photograph of a rare earth halide X-ray scintillator film. Figure 8 b, c, and d in the figure are photos of X-ray imaging of objects of different shapes using rare earth halide X-ray scintillator films. Figure 8 It can be seen that the scintillator exhibits excellent imaging clarity and restores the details in the image very well.

[0083] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a high-resolution, fast-attenuation rare earth halide X-ray scintillator film, characterized in that: The following steps are involved: 1) mixing cesium bromide, cerium bromide and water to obtain a precursor solution, and drying the precursor solution to obtain a precursor powder; 2) annealing the precursor powder to obtain rare earth halide X-ray scintillator powder; 3) Evaporating rare earth halide X-ray scintillator powder onto the surface of a substrate material to obtain a high-resolution, fast-attenuation rare earth halide X-ray scintillator film.

2. The method for preparing a high-resolution, fast-attenuation rare earth halide X-ray scintillator thin film according to claim 1, characterized in that: The mass volume ratio of cesium bromide, cerium bromide and water in step 1) is 5.746-7.022 g: 3.798 g: 15-25 mL; The drying temperature is 70-105°C.

3. The method for preparing a high-resolution, fast-attenuation rare earth halide X-ray scintillator thin film according to claim 2, characterized in that: The annealing temperature in step 2) is 150-300° C., and the annealing time is 10-60 min.

4. The method for preparing a high-resolution, fast-attenuation rare earth halide X-ray scintillator thin film according to claim 3, characterized in that: The vacuum degree of the environment at the beginning of the evaporation in step 3) is 2×10 -4 ~2×10 -3 pa.

5. The method for preparing a high-resolution, fast-attenuation rare earth halide X-ray scintillator thin film according to any one of claims 1 to 4, characterized in that: The rotation speed of the substrate material during the evaporation process in step 3) is 0 to 25 r / s.

6. The method for preparing a high-resolution, fast-attenuation rare earth halide X-ray scintillator thin film according to claim 5, characterized in that: The deposition rate of the rare earth halide X-ray scintillator powder on the surface of the substrate material in step 3) is 7. The method for preparing a high-resolution, fast-attenuation rare earth halide X-ray scintillator thin film according to claim 6, characterized in that: The substrate material in step 3) is a pre-treated glass substrate; The pretreatment method is to sequentially wash the glass substrate with water and alcohol, and then bombard the glass substrate with oxygen plasma for 5 to 7 minutes.

8. The high-resolution, fast-decaying rare earth halide X-ray scintillator film prepared by the method for preparing a high-resolution, fast-decaying rare earth halide X-ray scintillator film according to any one of claims 1 to 7, characterized in that: The thickness of the high-resolution, fast-decaying rare earth halide X-ray scintillator film is 2 to 13 μm.

Images