Sample cell for radioactive liquid scintillation analysis

Abstract

The invention provides a sample cell for radioactive liquid scintillation analysis. The sample cell comprises a sample cell body, a liquid outlet, a liquid inlet, a transparent window and a sample cell cover. The inner wall of the sample cell is provided with a nylon gauze, the nylon gauze is tightly attached to the inner wall of the sample cell, and the nylon gauze is 200-300 meshes. A liquid inlet and a liquid outlet are symmetrically formed in the outer wall of the sample pool, the liquid inlet and the liquid outlet are communicated with the interior of the sample pool, and radioactive liquid can enter the sample pool through the liquid inlet and flow out of the liquid outlet after passing through the interior of the sample pool. The transparent windows are arranged on the two sides of the sample cell, and rubber sealing rings are arranged between the transparent windows and the sample cell; and a sample cell cover is arranged outside the transparent window. The sample pool is filled with solid plastic scintillation particles, and the particle size of the solid plastic scintillation particles is 1-1000 microns; radioactive liquid flows in from the liquid inlet and is mixed with the solid plastic scintillation particles to excite the solid plastic scintillation particles to generate optical signals, and the optical signals are sent out through the transparent window. The scintillation material is plastic scintillation particles, and the chemical property is more stable.

Description

Technical Field

[0001] The invention relates to the technical field of radionuclide detection, and in particular to a sample pool for radioactive liquid scintillation analysis. Background Art

[0002] Radionuclide detection technology has important applications in many fields such as environmental monitoring, medical diagnosis, and nuclear material management. At present, radioactivity detection is mainly carried out using an offline liquid scintillation counter. Although this traditional method has certain advantages in sensitivity and detection range, it also has obvious operational limitations. The use process of an offline liquid scintillation counter usually includes multiple steps such as sample preparation, addition of scintillation fluid, and manual measurement. It not only consumes a lot of time and manpower, but also increases the possibility of human error due to the cumbersome operation steps. This manual operation method is difficult to meet the detection requirements of high efficiency, high precision, and low cost in large-scale or long-term monitoring projects. Therefore, the development of automated and process-simplified radioactivity detection equipment has gradually become a research hotspot.

[0003] In recent years, automated detection devices have gradually attracted attention. The automated system can significantly improve the efficiency of detection, reduce human intervention, and lower the professional requirements for operators by controlling the programming of operations such as sample loading, counting, and data recording. In addition, the high repeatability and high stability of automated equipment effectively reduce detection errors and improve the reliability and consistency of data. However, in automated radioactivity detection systems, the existing liquid scintillation technology still faces some technical bottlenecks. The amount of scintillation liquid used is large, and the radioactive organic waste liquid generated is difficult to handle.

[0004] Solid scintillator particle-based detection technology is believed to have the potential to break through these limitations. Unlike traditional liquid scintillators, solid scintillator particles have the characteristics of good material stability and strong reusability. At the same time, they can be integrated into automated flow analysis systems to achieve flow-based continuous detection, effectively reducing sample handling and preparation time.

[0005] The solid scintillation microsphere sample pool reported in the existing literature uses a pipeline sample pool. The main problem is that the sample capacity is small, resulting in a high detection line. The two materials used in Chinese patent CN202110305259.7, calcium fluoride and GAGG scintillation crystal particles, have poor transparency, which is not conducive to the transmission of optical signals. Therefore, optical fiber is used as an optical signal guide. Optical fiber is used as a signal output, which increases the transmission steps and distance of the optical signal. There is signal loss when the optical signal enters the optical fiber and during the optical fiber transmission process, which will reduce the counting efficiency. In addition, the diameter of the optical fiber is very small, and the light receiving area is limited, so the detection efficiency will be reduced. Summary of the invention

[0006] The present invention provides a sample cell for radioactive liquid scintillation analysis, wherein a liquid containing radioactive material is connected to the liquid inlet of the sample cell, and a light signal is generated during the process of flowing through solid plastic scintillation particles. The light signal is transmitted to a photomultiplier tube in an external detection device through a transparent window, thereby realizing the measurement of radioactivity.

[0007] Specifically, a sample pool for radioactive liquid scintillation analysis is proposed, including a sample pool, a liquid outlet, a liquid inlet, a transparent window and a sample pool cover; the inner wall of the sample pool is provided with a nylon mesh, the nylon mesh is arranged closely against the inner wall of the sample pool, and the nylon mesh is a 5-30000 mesh mesh.

[0008] The outer wall of the sample pool is symmetrically provided with a liquid inlet and a liquid outlet, which are connected to the inside of the sample pool. Radioactive liquid can enter the sample pool through the liquid inlet, and flow out from the liquid outlet after passing through the inside of the sample pool.

[0009] Transparent windows are arranged on both sides of the sample pool, a rubber sealing ring is arranged between the transparent window and the sample pool; and a sample pool cover is arranged outside the transparent window.

[0010] The sample pool is filled with solid plastic scintillating particles, and the particle size of the solid plastic scintillating particles can be selected from 1 to 1000 microns. The radioactive liquid flows in from the liquid inlet, mixes with the solid plastic scintillating particles, and excites the solid plastic scintillating particles to generate light signals, which are emitted through the transparent window. After being emitted, they are transmitted to the photomultiplier tube in the external detection equipment, thereby realizing the measurement of radioactivity.

[0011] As a preferred technical solution, the sample pool cover is threadedly connected or snap-fitted to the sample pool.

[0012] As a preferred technical solution, the solid plastic scintillating particles are spherical solid particles.

[0013] As a preferred technical solution, the particle size of the solid plastic scintillating particles is 100 microns.

[0014] As a preferred technical solution, the transparent window is a transparent window made of transparent acrylic material.

[0015] As a preferred technical solution, the main structure of the sample pool is a cylindrical structure, and a liquid inlet and a liquid outlet are symmetrically arranged on the curved surface of the sample pool.

[0016] As a preferred technical solution, the cylindrical structure is made of metal or plastic.

[0017] As a preferred technical solution, the cylindrical structure is made of white polytetrafluoroethylene.

[0018] As a preferred technical solution, the inner diameter of the cylindrical structure is 6 to 8 centimeters and the height is 3 to 4 centimeters.

[0019] As a preferred technical solution, the liquid inlet and the liquid outlet are connected to a liquid pipeline.

[0020] Compared with the prior art, the present invention has achieved the following technical effects: (1) The scintillating material used in the present invention is plastic scintillating microparticles, which have more stable chemical properties. Plastic scintillating microspheres are high molecular polymers. Compared with inorganic materials such as calcium fluoride and GAGG used in the prior art, they have good chemical stability and will not dissolve in acid solutions. During use, they will not break and produce fine particles, thereby causing the loss of scintillating materials or increased column pressure. The material of the sample pool is transparent, so the light signal can be directly output.

[0021] (2) The signal output window and transparent window of the present invention are flat, which makes it easier to couple with the photomultiplier tube. The signal directly reaches the photomultiplier tube, which is helpful for signal reception and improves detection sensitivity. The wavelength of the light signal generated by the plastic scintillation microsphere can be adjusted by the fluorescent agent. The wavelength of the light signal in the present invention is between 400 and 450 nanometers, preferably 425 nanometers. Compared with inorganic materials such as calcium fluoride and GAGG in the prior art, it is more suitable for photomultiplier tube detection and has higher detection efficiency.

[0022] (3) The positions of the liquid inlet and the liquid outlet of the sample pool are preferably symmetrically arranged to ensure uniform flow of the fluid. The present invention adopts an integrated solid scintillation detection pool, rationally utilizes space, increases the sample capacity, can effectively reduce the detection line, and can obtain more accurate measurement results under the same measurement time.

[0023] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent from the description, or may be understood by practicing the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of a sample cell structure for radioactive liquid scintillation analysis proposed in an embodiment of the present invention Figure 1 ;

[0025] Figure 2 A schematic diagram of a sample cell structure for radioactive liquid scintillation analysis proposed in an embodiment of the present invention Figure 2 ;

[0026] Figure 3 This is a schematic structural diagram of an assembled sample cell for radioactive liquid scintillation analysis proposed in an embodiment of the present invention.

[0027] Description of reference numerals:

[0028] Sample pool 1; liquid outlet 2; liquid inlet 3; transparent window 4; sample pool cover 5; nylon mesh 6; sealing ring 7; scintillation particles 8. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. In the description of the present invention, it should be noted that the term "or" is usually used in the sense of including "and / or", unless the content clearly indicates otherwise.

[0030] It should be understood that the various steps described in the method implementation of the present application can be performed in different orders and / or performed in parallel. In addition, the method implementation may include additional steps and / or omit the steps shown. The scope of the present application is not limited in this respect.

[0031] The term "including" and its variations used in the present invention are open inclusions, i.e., "including but not limited to". The term "based on" means "based at least in part on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments". The relevant definitions of other terms will be given in the following description.

[0032] It should be noted that the modifications of "one" and "plurality" mentioned in this application are illustrative rather than restrictive, and those skilled in the art should understand that unless otherwise clearly indicated in the context, it should be understood as "one or more". "Plurality" should be understood as two or more.

[0033] Example

[0034] like Figure 1-3 As shown, this embodiment provides a sample cell 1 for radioactive liquid scintillation analysis, comprising a sample cell 1, a liquid outlet 2, a liquid inlet 3, a transparent window 4 and a sample cell cover 5. In order to prevent leakage of solid scintillation particles, a nylon mesh 6 is provided on the inner wall of the sample cell 1. The nylon mesh 6 is arranged close to the inner wall of the sample cell 1. The mesh number can be selected in the range of 5 to 30,000 meshes. Preferably, the nylon mesh 6 is a 200-300 mesh mesh. The purpose of the mesh is to prevent the scintillation particles 8 from leaking from the liquid inlet 3 and the liquid outlet 2, so the aperture corresponding to the mesh number is smaller than the diameter of the scintillation particles 8.

[0035] The outer wall of the sample pool 1 is symmetrically provided with a liquid inlet 3 and a liquid outlet 2, which are connected to the interior of the sample pool 1. Radioactive liquid can enter the sample pool 1 through the liquid inlet 3, and flow out from the liquid outlet 2 after passing through the interior of the sample pool 1.

[0036] Preferably, the main structure of the sample pool 1 is a cylindrical structure, and the liquid inlet 3 and the liquid outlet 2 are symmetrically arranged on the curved surface of the sample pool 1, and the symmetrical arrangement ensures uniform flow of the fluid.

[0037] Transparent windows 4 are provided on both sides of the sample pool 1. The transparent windows 4 are located at two plane positions of the sample pool 1, that is, located on the two bottom surfaces of the cylindrical structure sample pool 1. A rubber sealing ring 7 is provided between the transparent window 4 and the sample pool 1 for sealing to ensure the airtightness and safety of the interior of the sample pool 1. A sample pool cover 5 is provided outside the transparent window 4. Preferably, the sample pool cover 5 is threadedly connected or snap-connected to the sample pool 1, preferably in an ordered threaded connection mode, for easy installation and disassembly.

[0038] like Figure 2-3 As shown, transparent solid plastic scintillating particles 8 are filled in the sample pool 1, and the particle size of the scintillating microspheres can be selected to be 1-1000 microns, preferably 100 microns. The scintillating material used in the present invention is plastic scintillating microparticles, which have more stable chemical properties. The plastic scintillating microspheres 8 are high molecular polymers. Compared with the inorganic materials such as calcium fluoride and GAGG in the prior art, they have good chemical stability and will not dissolve in acid solutions. During use, they will not break and produce fine particles, thereby causing the loss of scintillating materials or increased column pressure. The radioactive liquid flows in from the liquid inlet 3, mixes with the solid plastic scintillating particles 8, and excites the solid plastic scintillating microparticles to generate light signals. The light signals are emitted through the transparent window 4 and detected by a matching detection device. Finally, the liquid flows out from the liquid outlet 2.

[0039] The signal output window of the present invention is a plane, which is easier to couple with the photomultiplier tube of the external detection equipment, and the signal directly reaches the photomultiplier tube, which is helpful for signal reception and improves detection sensitivity. The wavelength of the light signal generated by the plastic scintillation microsphere can be adjusted by the fluorescent agent. The wavelength of the light signal generated in the present invention is between 400 and 450 nanometers, preferably 425 nanometers. Compared with inorganic materials such as calcium fluoride and GAGG in the prior art, it is more suitable for photomultiplier tube detection and has higher detection efficiency.

[0040] Preferably, the solid plastic scintillating particles 8 are spherical solid particles. The spherical solid particles are regular spherical particles, which can make the gaps between the particles uniform and consistent. The gaps between the particles can be changed by adjusting the radius of the spherical particles, thereby maximizing the mixing reaction between the scintillating particles 8 and the radioactive liquid in the sample pool 1 to generate light signals, thereby improving the detection capability of the sample pool 1.

[0041] Preferably, the transparent window 4 is a transparent window 4 body made of transparent acrylic material. The transparent window 4 is located at two plane positions of the sample pool 1. The transparent window 4 body is more convenient for the light signal to be transmitted. The transparent window 4 is arranged between the sample pool 1 and the sample pool cover 5, and the transparent window 4 is clamped on the side of the sample pool 1 through the connection between the sample pool cover 5 and the sample pool 1.

[0042] Preferably, the cylindrical structure is made of metal or plastic material, preferably plastic, which can increase the service life of the sample pool 1.

[0043] Preferably, Figure 2-3 As shown, the cylindrical structure is made of white polytetrafluoroethylene material. The cylindrical structure is made into a hollow columnar structure, and the middle is filled with transparent solid plastic scintillating particles 8, which generate light signals when the radioactive liquid flows through.

[0044] Preferably, the diameter of the cylindrical structure body of the present invention can be in the range of 0.001 to 1 meter, preferably 6 to 8 centimeters, and the height can be in the range of 0.001 to 1 meter, preferably 3 to 4 centimeters.

[0045] Preferably, the liquid inlet 3 and the liquid outlet 2 are connected to a liquid pipeline, and the liquid inlet 3 and the liquid outlet 2 are preferably arranged in a pagoda design to facilitate connection of the liquid pipeline.

[0046] The scintillating material used in the present invention is plastic scintillating particles, and further, it is spherical transparent plastic scintillating particles with stable chemical properties. And the material is transparent, so the light signal can be directly output. The present invention adopts a flat signal window, does not require signal collection and other operations, and can use a photomultiplier tube to directly receive the signal, the light signal will not be lost, and the operation is simple and the cost is reduced. Specifically, the sample pool 1 of the present invention was used to measure three nuclides of H-3, C-14 and Sr-90 in the aqueous solution, and the detection efficiency is shown in the following table.

[0047] Nuclide Detection efficiency H-3 0.1％ C-14 30％ Sr-90 70％

[0048] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Claims

1. A sample cell for radioactive liquid scintillation analysis, characterized in that: It includes a sample pool, a liquid outlet, a liquid inlet, a transparent window and a sample pool cover; the inner wall of the sample pool is provided with a nylon mesh, the nylon mesh is arranged closely against the inner wall of the sample pool, and the nylon mesh is a 5-30000 mesh mesh; The liquid inlet and the liquid outlet are symmetrically arranged on the outer wall of the sample pool, and the liquid inlet and the liquid outlet are connected to the inside of the sample pool, so that the radioactive liquid can enter the sample pool through the liquid inlet, and flow out from the liquid outlet after passing through the inside of the sample pool; The transparent windows are arranged on both sides of the sample pool, and a rubber sealing ring is arranged between the transparent window and the sample pool; the sample pool cover is arranged outside the transparent window; The sample pool is filled with solid plastic scintillation particles, the particle size of which is 1-1000 microns; radioactive liquid flows in from the liquid inlet, mixes with the solid plastic scintillation particles, and excites the solid plastic scintillation particles to generate light signals, which are emitted through the transparent window.

2. A sample cell for radioactive liquid scintillation analysis according to claim 1, characterized in that: The sample pool cover is threadedly connected or snap-fitted to the sample pool.

3. A sample cell for radioactive liquid scintillation analysis according to claim 1, characterized in that: The solid plastic glittering particles are spherical solid particles.

4. A sample cell for radioactive liquid scintillation analysis according to claim 3, characterized in that: The particle size of the solid plastic scintillating particles is 100 microns.

5. A sample cell for radioactive liquid scintillation analysis according to claim 1, characterized in that: The transparent window is a transparent window made of transparent acrylic material.

6. A sample cell for radioactive liquid scintillation analysis according to claim 1, characterized in that: The main structure of the sample pool is a cylindrical structure, and the liquid inlet and the liquid outlet are symmetrically arranged on the curved surface of the sample pool.

7. A sample cell for radioactive liquid scintillation analysis according to claim 6, characterized in that: The cylindrical structure is made of metal or plastic.

8. A sample cell for radioactive liquid scintillation analysis according to claim 7, characterized in that: The cylindrical structure is made of white polytetrafluoroethylene.

9. A sample cell for radioactive liquid scintillation analysis according to claim 7, characterized in that: The inner diameter of the cylindrical structure is 6 to 8 centimeters, and the height is 3 to 4 centimeters.

10. A sample cell for radioactive liquid scintillation analysis according to any one of claims 1 to 9, characterized in that: The liquid inlet and the liquid outlet are connected to a liquid pipeline.

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