Photo-luminescence detection material, photo-luminescence detector and preparation method and application of photo-luminescence detection material and photo-luminescence detector

Abstract

The invention discloses a photoluminescence detection material, a photoluminescence detector and a preparation method and application thereof, and relates to the technical field of radiation protection dosimetry. The photoluminescence detection material is prepared by sequentially carrying out compression molding and solid-phase sintering on mixed powder, the mixed powder takes potassium chloride as a main body, a single compound containing aluminum ions is doped in the mixed powder, and the molar percentage of the aluminum ions in the mixed powder is 0.001-0.01 mol%. The photoluminescence detection material is wide in raw material source, easy to obtain, simple and mature in process, low in equipment requirement, low in sintering temperature, energy-saving, environment-friendly, capable of effectively reducing the manufacturing cost of the photoluminescence detection material and suitable for industrial large-scale production and application. Moreover, a photoluminescence detector prepared from the photoluminescence detection material is good in reusability and high in uniformity, has linear dose response in 1-1000mGy, and can be applied to a low-dose gamma radiation measurement scene.

Description

Technical Field

[0001] The present invention relates to the field of radiation protection dosimetry technology, and in particular to a photoluminescence detection material, a photoluminescence detector, and a preparation method and application thereof. Background Art

[0002] With the development of nuclear technology applications and the increase in the number of practitioners, the field of radiation dose monitoring has ushered in development. Compared with thermoluminescence dosimetry, photoluminescence has gradually become a mainstream technology abroad because of its all-optical properties, convenient operation, and high sensitivity. However, the promotion of photoluminescence technology has always been restricted by photoluminescence materials. It was initially introduced in China for geological applications, and the dosimetry technology reserves are still insufficient, which makes it difficult to promote domestic photoluminescence dose measurement technology. For many years, people have been looking for materials with better performance and lower cost. At present, the more common materials for commercial photoluminescence dosimeters in the field of personal doses are Al2O3:C and BeO, but the production process of these two materials is complicated, the cost is high, the energy consumption is high, and it is difficult to promote their application. Summary of the invention

[0003] One of the purposes of the present invention is to provide a photoluminescence detection material with potassium chloride as a matrix and doped with aluminum ions, which has the characteristics of good linear response range, good multiplexability and low production cost.

[0004] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: the optically stimulated luminescence detection material is made of mixed powders through pressing and solid-phase sintering in sequence, wherein the mixed powders are mainly composed of potassium chloride (KCl) and doped with aluminum ions (Al 3+ ), the molar percentage of aluminum ions in the mixed powder is 0.001-0.01 mol % (such as 0.001 mol %).

[0005] Wherein, the single compound containing aluminum ions is aluminum oxide (Al2O3).

[0006] The pressing pressure used in the pressing process is 1.5-2Mpa (such as 1.75Mpa), and the pressing time is at least 1 minute (such as 1 minute); the temperature condition of the solid phase sintering is 650-680°C (such as 650°C, 680°C), the heating rate is 5°C / min, and the holding time is 6-8 hours (such as 6 hours). In addition, the sintering atmosphere is air atmosphere.

[0007] Wherein, the particle size of the mixed powder is 125-150 μm.

[0008] In addition, the present invention also relates to a photoluminescence detector, which is made of the above-mentioned photoluminescence detection material.

[0009] Furthermore, the present invention also relates to a method for preparing an optically stimulated luminescence detector, and the preparation process mainly comprises the following steps: (1) Using potassium chloride as the main component and aluminum oxide as the dopant, grinding and mixing the two components, and controlling the molar percentage of aluminum ions in the obtained mixed powder to be 0.001-0.01 mol% (e.g., 0.001 mol%); (2) taking an appropriate amount of the mixed powder and placing it into a molding mold (such as an optical mold), pressing the mixed powder at a pressing pressure of 1.5-2 MPa (such as 1.75 MPa) for at least 1 minute (such as 1 minute) to obtain a green body; (3) The green body is heated to 650-680°C (e.g., 650°C, 680°C) for solid phase sintering (the sintering atmosphere may be an air atmosphere), kept at that temperature for 6-8 hours (e.g., 6 hours), and cooled (e.g., naturally cooled to room temperature) to obtain a photoluminescence detector.

[0010] Wherein, in step (1), the mass ratio of potassium chloride to aluminum oxide is 5:0.0068, for example, the weight of potassium chloride is 5 g, and the weight of aluminum oxide is 0.0068 g.

[0011] The heating rate in step (3) is 5°C / min.

[0012] Wherein, in step (1), the potassium chloride and aluminum oxide are both of analytical grade, and the particle size of the mixed powder is 125-150 μm.

[0013] Wherein, in step (2), the cavity of the molding mold (such as an optical mold) is cylindrical, the cavity diameter is 0.45 cm, and the mass of the mixed powder placed in the molding mold is 0.04 g.

[0014] Finally, the present invention also relates to the application of the aforementioned optically stimulated luminescence detector in a radiation dosimeter.

[0015] The present invention uses KCl as a matrix and Al2O3 as an activator (dopant) to prepare a KCl:Al photoluminescence detection material by a sintering method. The sintering method used in the present invention is a type of solid-phase reaction, with a mature process, low requirements for equipment, and no requirements for the reaction atmosphere (air atmosphere is sufficient). The entire preparation process is relatively simple, the raw materials are widely available, and the acquisition cost is low. It can effectively reduce the production cost of photoluminescence detection materials and is suitable for industrial-scale production and application. Tests have shown that the photoluminescence detector made of the above-mentioned photoluminescence detection material has a linear dose response of 1mGy-1000mGy, a high linear fit, good dosimetric characteristics, strong uniformity, and good reusability. It can be used as a dosimeter for low-dose measurement occasions. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The figure is a comparison between the X-ray diffraction pattern of the prepared optically stimulated luminescence detection material and the standard card; Figure 2 Schematic diagram of the preparation process of the photoluminescence detector in the embodiment; Figure 3 The thermoluminescence emission curve of the prepared photoluminescence detector; Figure 4 This is the linear response diagram of the prepared photoluminescence detector to the photoluminescence dose; Figure 5 This is a physical picture of the prepared optically stimulated luminescence detector. DETAILED DESCRIPTION

[0017] In order to facilitate the understanding of those skilled in the art, the present invention is further described below in conjunction with the examples and drawings, and the contents mentioned in the examples are not limitations of the present invention. It should be noted in advance that the following examples were completed in the laboratory, and those skilled in the art should understand that the amounts of the components given in the examples only represent the ratio relationship between the components, rather than specific limitations.

[0018] A photoluminescence detector is a certain amount of photoluminescence material, or a mixture of the material and other non-luminescent materials in a certain weight ratio and having a certain weight, shape or size.

[0019] In photoluminescence materials (i.e., photoluminescence detection materials), KCl, as a widely available alkali metal halide, can introduce defects and luminescence centers by doping elements, optimize alkali halides, change the performance of materials, and improve luminescence efficiency. At the same time, it is combined with mature and low-cost sintering methods to reduce costs. Common doping elements include rare earth elements such as Ce, Sm, Tb, Eu, and Pr, but rare earth elements are expensive. In radiation dose materials, controlling the concentration of doped KCl can significantly improve the response intensity of the material in view of the sensitivity of KCl to dose.

[0020] Based on this, the present invention uses potassium chloride (KCl) as a matrix and contains aluminum ions (Al 3+) is used as a dopant, and the two are ground and mixed, and the molar percentage of aluminum ions in the mixture is strictly controlled to be 0.001-0.01mol%. The mixture powder is pressed and formed, and then solid-phase sintered at 650-680°C to finally obtain potassium chloride photoluminescence detection material doped with aluminum ions. The raw materials used to prepare the above-mentioned photoluminescence detection materials are widely available and easy to obtain. The process is simple and mature, with low requirements on equipment, low sintering temperature, energy saving and environmental protection, which can effectively reduce the production cost of photoluminescence detection materials and is suitable for industrial-scale production and application. In addition, the photoluminescence detector made of the above-mentioned photoluminescence detection material has good reusability, strong uniformity, and a linear dose response of 1-1000mGy, and can be used in low-dose γ radiation measurement scenarios. Example 1

[0021] The purpose of this embodiment is to prepare aluminum-doped potassium chloride photoluminescence detection material.

[0022] 1. Experimental preparation: 1. Raw materials: analytical grade alumina and potassium chloride.

[0023] 2. Equipment: analytical balance, agate mortar, sieve, tablet press, optical mold, muffle furnace.

[0024] 2. Preparation of optically stimulated luminescence detection materials: (1) An analytical balance is used to weigh analytically pure aluminum oxide and potassium chloride raw materials required to prepare a target mass mixture, wherein the blending ratio is 0.001-0.01 mol% (0.001 mol% in this embodiment) of Al ions, and the relative molecular masses of aluminum oxide and potassium chloride are 101.96 and 74.55, respectively.

[0025] (2) After weighing, put the raw materials into an agate mortar and mix and grind them thoroughly for 15-20 minutes to complete the pre-mixing. The powdered mixture after grinding and mixing is placed in a sieve and sieved to obtain a mixture with a particle size of 125-150μm. This step is to ensure the uniformity of the material and control the effect of particle size on material performance.

[0026] (3) 40 mg of the ground and sieved mixture was weighed using an analytical balance and placed in an optical mold (having a cylindrical cavity with a cavity diameter of 0.45 cm). The mixture was pressed using a tablet press at a pressure of 1.5-2 MPa (1.75 MPa in this embodiment) for 1 minute, and then demolded to obtain a sheet-like solid mixture with a diameter of 0.45 cm and a thickness of 1 mm. The purpose of this step is to reduce the air gap, increase the particle diffusion rate, and obtain a uniform shape.

[0027] (4) The flaky mixture is placed in an alumina crucible, placed in a muffle furnace, and heated from room temperature to 650-680°C (650°C in this embodiment) at a heating rate of 5°C / min in an air atmosphere. The mixture is sintered and kept warm for 6-8 hours (6 hours in this embodiment). The mixture is then cooled to room temperature to obtain an aluminum-doped potassium chloride photoluminescence detection material (KCl:Al).

[0028] Figure 1 The comparison of the X-ray diffraction pattern shown and the standard card shows that the photoluminescence detection material (KCl:Al) was successfully prepared in this embodiment.

[0029] In the above production process, the sintering method is essentially a solid-phase reaction. The raw materials and equipment required for the production steps are simple. In addition, since the melting point of potassium chloride is 776°C, it only needs to be heated to the Thanman temperature, which is energy-saving and environmentally friendly while reducing costs. Example 2

[0030] The purpose of this example is to prepare an optically stimulated luminescence detector and test its performance. For the specific process, please refer to Figure 2 .

[0031] 1. Experimental preparation: Raw materials: Analytical grade alumina and potassium chloride.

[0032] Equipment: analytical balance, agate mortar, sieve, tablet press, optical mold, muffle furnace, annealing furnace, thermoluminescence reader, photoluminescence measurement system, optical annealing furnace, blood irradiator.

[0033] 2. Preparation of optically stimulated luminescence detectors: (1) Use an analytical balance to weigh 0.0068 g of aluminum oxide and 5 g of potassium chloride, that is, the molar ratio of Al ions is 0.001 mol%, where the relative molecular masses of aluminum oxide and potassium chloride are 101.96 and 74.55, respectively.

[0034] (2) After weighing, the raw materials are placed in an agate mortar and ground thoroughly for 15-20 minutes to complete pre-mixing. The ground and mixed powder mixture is placed in a sieve and sieved to obtain a powder mixture with a particle size of 125-150 μm.

[0035] (2) Take 0.04 g of the mixture each time and place it in an optical mold (having a cylindrical cavity with a cavity diameter of 0.45 cm). Use a tablet press to press at a pressure of 1.75 MPa for 1 minute, and demold to obtain a sheet-like solid mixture with a diameter of 0.45 cm and a thickness of 1 mm.

[0036] (3) The flake mixture is placed in an alumina crucible, placed in a muffle furnace, and heated to 680°C at a heating rate of 5°C / min at room temperature in an air atmosphere. The mixture is sintered at this temperature for 6 hours, and then naturally cooled to room temperature to obtain an optically stimulated luminescence detector with a certain mechanical strength (the prepared sample can be found in Figure 5 ).

[0037] 3. Test of optically stimulated luminescence detector: 1. Trap parameter test of OSL detector (1) The prepared photoluminescence detector was annealed in an annealing furnace at 400°C for 20 minutes to remove the interference of the accumulated background.

[0038] (2) After irradiation with 10 mGy, the samples were heated to 250°C using a thermoluminescence reader and the luminescence of the photoluminescence detector was measured.

[0039] (3) After the measurement is completed, the traps of the main luminescence peak are calculated and analyzed.

[0040] like Figure 3 As shown, the main thermoluminescence peak is at 152℃, the kinetic order is 2nd order, the average activation energy is 0.9411eV, and the average frequency factor is 2.3239×10 11 s -1 .

[0041] 2. Uniformity test of OSL detector (1) The prepared photoluminescence detectors were placed in groups of four into a four-element container and photoannealed in a photoannealing furnace for 30 minutes.

[0042] (2) Use the photoluminescence measurement system to read the background of the prepared photoluminescence detector. After irradiation with 10 mGy, read the photoluminescence count again.

[0043] Due to the mold used and the particle size screening of the mixture, the uniformity of the obtained optically stimulated luminescence detector can be good, ensuring its accuracy when used as a dosimeter.

[0044] 3. Multiplexability test of OSL detector (1) After annealing, the photoluminescence detector reads the background, irradiates 10 mGy, and reads the photoluminescence counts.

[0045] (2) Use a photoannealing furnace to photoanneal the OSL detector, irradiate it with 10 mGy, and read it again. This process is repeated 9 times.

[0046] The photoluminescence detector was irradiated multiple times, and the coefficient of variation was calculated to be 7.4%. The photoluminescence detector made of this material can be reused multiple times to ensure reliability.

[0047] 4. Dosimetry test of OSL detector (1) Prepare 10 sets of four-element containers sealed with optically stimulated luminescence detectors and perform photoannealing on them.

[0048] (2) Using a sample with an activity of 9.62×10 13 The blood irradiator with a γ irradiation source of 0.1 Bq was used to irradiate with 1mGy, 3mGy, 5mGy, 10mGy, 30mGy, 50mGy, 100mGy, 500mGy, 750mGy and 1000mGy in sequence.

[0049] (3) Use the photoluminescence measurement system to excite and read 10 groups of four-element containers to obtain photoluminescence counts. After fitting, Figure 4 As shown, the dose response is linear in the range of 1-1000 mGy, and the fitting effect is good.

[0050] Through the above tests, it can be determined that the photoluminescence detector prepared by the aluminum-doped potassium chloride photoluminescence detection material (KCl:Al) in this embodiment has high uniformity, good reusability, and a linear dose response of 1-1000mGy. In addition, it has a simple production process, low equipment requirements, and low cost, and has application potential in low-dose measurement scenarios.

[0051] The above embodiments are preferred implementation schemes of the present invention. In addition, the present invention may also be implemented in other ways. Any obvious replacement without departing from the concept of the present technical solution is within the protection scope of the present invention.

[0052] Finally, it should be emphasized that in order to allow ordinary technicians in the field to more easily understand the improvements of the present invention over the prior art, some descriptions of the present invention have been simplified, and for the sake of clarity, some other elements are omitted in this application document. Those skilled in the art should realize that these omitted elements may also constitute the content of the present invention.

Claims

1. Optically stimulated luminescence detection material, characterized in that: The invention is prepared by sequentially pressing and solid-phase sintering mixed powders, wherein the mixed powders are mainly potassium chloride and doped with a single compound containing aluminum ions, and the molar percentage of aluminum ions in the mixed powders is 0.001-0.01 mol%.

2. The optically stimulated luminescence detection material according to claim 1, characterized in that: The single compound containing aluminum ions is aluminum oxide.

3. The optically stimulated luminescence detection material according to claim 1 or 2, characterized in that: The pressing pressure of the pressing molding is 1.5-2Mpa, and the pressing time is at least 1 minute; the temperature condition of the solid phase sintering is 650-680°C, the heating rate is 5°C / min, and the insulation time is 6-8 hours.

4. The optically stimulated luminescence detection material according to claim 1 or 2, characterized in that: The particle size of the mixed powder is 125-150 μm.

5. An optically stimulated luminescence detector, characterized in that: Made of the photoluminescence detection material according to any one of claims 1 to 4.

6. A method for preparing an optically stimulated luminescence detector, characterized in that: The steps include: (1) Using potassium chloride as the main component and aluminum oxide as the dopant, the two are ground and mixed, and the molar percentage of aluminum ions in the obtained mixed powder is controlled to be 0.001-0.01 mol%; (2) taking an appropriate amount of the mixed powder and placing it into a molding mold, pressing the mixed powder at a pressing pressure of 1.5-2 MPa for at least 1 minute to obtain a green body; (3) The green body is heated to 650-680°C for solid phase sintering, kept at this temperature for 6-8 hours, and then naturally cooled to obtain an optically stimulated luminescence detector.

7. The method for preparing an optically stimulated luminescence detector according to claim 6, characterized in that: The heating rate in step (3) is 5°C / min.

8. The method for preparing an optically stimulated luminescence detector according to claim 6, characterized in that: In step (1), the potassium chloride and aluminum oxide are both of analytical grade, and the particle size of the mixed powder is 125-150 μm.

9. The method for preparing an optically stimulated luminescence detector according to claim 6, characterized in that: In step (2), the mold cavity of the molding die is cylindrical, the diameter of the mold cavity is 0.45 cm, and the mass of the mixed powder placed in the molding die is 0.04 g.

10. Use of the optically stimulated luminescence detector according to claim 5 in a radiation dosimeter.

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