A sample cell for radio liquid scintillation analysis

Abstract

The application provides a sample cell for radioactive liquid scintillation analysis, which comprises a sample cell, a liquid outlet, a liquid inlet, a transparent window and a sample cell cover; nylon screen gauze is arranged on the inner wall of the sample cell and closely adheres to the inner wall of the sample cell, and the nylon screen gauze is 200-300 mesh screen gauze. The liquid inlet and the liquid outlet are symmetrically arranged on the outer wall of the sample cell and are connected with the inside of the sample cell, radioactive liquid can enter the sample cell through the liquid inlet, and flows out from the liquid outlet after passing through the inside of the sample cell. The transparent window is arranged on both sides of the sample cell, and a rubber sealing ring is arranged between the transparent window and the sample cell; the sample cell cover is arranged outside the transparent window. Solid plastic scintillation particles are filled in the sample cell, the particle size of the solid plastic scintillation particles is 1-1000 microns; radioactive liquid flows into the sample cell from the liquid inlet, mixes with the solid plastic scintillation particles, excites the solid plastic scintillation particles to generate light signals, and the light signals are emitted through the transparent window. The scintillation material is plastic scintillation particles, and the chemical property is more stable.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of radionuclide detection, and particularly relates to a sample cell for radioactive liquid scintillation analysis. BACKGROUND

[0002] Radionuclide detection technology has important applications in environmental monitoring, medical diagnosis, nuclear material management and other fields. At present, radioactive detection is mainly carried out by offline liquid scintillation counters. Although this traditional method has certain advantages in sensitivity and detection range, it also has obvious operational limitations. The use process of the offline liquid scintillation counter usually includes sample preparation, addition of scintillation liquid, manual measurement and other steps, which not only consumes a lot of time and manpower, but also increases the possibility of human error due to the complicated 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 automatic and process-simplified radioactive 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 detection efficiency, reduce human intervention and reduce the professional requirements for the operator by controlling the programmed operations such as sample loading, counting and data recording. In addition, the high repeatability and high stability of the automated equipment effectively reduce the detection error and improve the reliability and consistency of the data. However, in the automated radioactive detection system, the existing liquid scintillation technology still faces some technical bottlenecks. The amount of scintillation liquid is large, and the generated radioactive organic waste liquid is difficult to handle.

[0004] The detection technology based on solid scintillation micro-particles is considered to be able to break through these limitations. Unlike traditional liquid scintillators, solid scintillation micro-particles have good material stability and strong reusability, and can be integrated into an automated flow analysis system to realize flow-type continuous detection, effectively reducing the sample processing and preparation time.

[0005] The existing literature reports that the solid scintillation microsphere sample cell adopts a pipeline type sample cell, and the main problem is that the sample capacity is small, which leads to the disadvantage of high detection line. In Chinese patent CN202110305259.7, the transparency of calcium fluoride and GAGG scintillation crystal particles, which are two kinds of materials, is poor, which is not conducive to the transmission of light signals, and therefore an optical fiber is used as a light signal guide. The use of optical fiber as a signal output increases the transmission steps and distance of the light signal, and the light signal is lost in the process of entering the optical fiber and being transmitted in the optical fiber, which reduces the counting efficiency. In addition, the diameter of the optical fiber is very small, and the light collection area is limited, so the detection efficiency is reduced. SUMMARY

[0006] The application provides a sample cell for radioactive liquid scintillation analysis. A liquid containing radioactive substances is connected to the liquid inlet of the sample cell. When the liquid flows through the solid plastic scintillation particles, light signals are generated. The light signals are transmitted to the photomultiplier tube in the external detection device through the transparent window, thereby realizing the measurement of radioactivity.

[0007] Specifically, the application provides a sample cell for radioactive liquid scintillation analysis, which comprises a sample cell, a liquid outlet, a liquid inlet, a transparent window and a sample cell cover. The inner wall of the sample cell is provided with nylon screen gauze, which is arranged close to the inner wall of the sample cell. The nylon screen gauze is 5-30,000 mesh screen gauze.

[0008] The liquid inlet and the liquid outlet are symmetrically arranged on the outer wall of the sample cell and are connected with the inside of the sample cell. The radioactive liquid can enter the sample cell through the liquid inlet and flow out from the liquid outlet after passing through the inside of the sample cell.

[0009] The transparent window is arranged on both sides of the sample cell, and a rubber sealing ring is arranged between the transparent window and the sample cell. The sample cell cover is arranged outside the transparent window.

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

[0011] As a preferred technical solution, the sample cell cover is threadedly connected or snap-connected with the sample cell.

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

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

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

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

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

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

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

[0019] As a preferred technical solution, the liquid inlet is connected with the liquid outlet through a liquid pipeline.

[0020] The present application has the following technical effects relative to the prior art: (1) The scintillation material used in the present application is plastic scintillation micro-particles, which have better chemical stability. The plastic scintillation micro-spheres are high-molecular polymers, and have better chemical stability than the inorganic materials such as calcium fluoride and GAGG used in the prior art, and will not dissolve in an acid solution. In use, the plastic scintillation micro-spheres will not break to produce fine particles, thereby causing loss of the scintillation material or an increase in column pressure. Moreover, the material of the sample cell is transparent, so that the optical signal can be directly outputted.

[0021] (2) The signal output window and the transparent window of the present application are flat, and are more easily coupled with a photomultiplier tube, so that the signal directly reaches the photomultiplier tube, which is helpful for signal reception and improves the detection sensitivity. The wavelength of the optical signal generated by the plastic scintillation micro-spheres can be adjusted by a fluorescent agent, and in the present application, the wavelength of the optical signal is between 400 nm and 450 nm, preferably 425 nm. Compared with the inorganic materials such as calcium fluoride and GAGG used in the prior art, the plastic scintillation micro-spheres are more suitable for detection by a photomultiplier tube, and have higher detection efficiency.

[0022] (3) The positions of the liquid inlet and the liquid outlet of the sample cell are preferably symmetrically arranged to ensure uniform flow of the fluid. The present application uses an integrated solid scintillation detection cell, which rationally utilizes the space, improves the capacity of the sample, effectively reduces 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 to those skilled in the art from the description, or can be learned by practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 A sample cell structure diagram for radioactive liquid scintillation analysis according to an embodiment of the present application Figure 1 ;

[0025] Figure 2 A sample cell structure diagram for radioactive liquid scintillation analysis according to an embodiment of the present application Figure 2 ;

[0026] Figure 3 A sample cell structure diagram for radioactive liquid scintillation analysis according to an embodiment of the present application

[0027] BRIEF DESCRIPTION OF DRAWINGS

[0028] Sample cell 1; liquid outlet 2; liquid inlet 3; transparent window 4; sample cell cover 5; nylon screen 6; sealing ring 7; scintillation particles 8. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. In the description of this invention, it should be noted that the term "or" is generally used to include the meaning of "and / or," unless otherwise expressly indicated.

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

[0031] The term "comprising" and its variations as used in this invention are open-ended, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". Definitions of other terms will be given in the description below.

[0032] It should be noted that the terms "one" and "multiple" used in this application are illustrative rather than restrictive, and those skilled in the art should understand that, unless explicitly stated otherwise in the context, they should be interpreted as "one or more". "Multiple" should be understood as two or more.

[0033] Examples

[0034] like Figures 1-3 As shown, this embodiment proposes a sample cell 1 for radioactive liquid scintillation analysis, including a sample cell 1, an outlet 2, an inlet 3, a transparent window 4, and a sample cell cover 5. 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 set tightly against the inner wall of the sample cell 1. The mesh count can be selected from 5 to 30,000 meshes. Preferably, the nylon mesh 6 is 200 to 300 mesh. The purpose of the mesh is to prevent scintillation particles 8 from leaking out from the inlet 3 and the outlet 2, so the aperture corresponding to the mesh count must be smaller than the diameter of the scintillation particles 8.

[0035] The outer wall of the sample cell 1 is symmetrically provided with an inlet 3 and an outlet 2. The inlet 3 and the outlet 2 are connected to the inside of the sample cell 1. Radioactive liquid can enter the sample cell 1 through the inlet 3, and after passing through the inside of the sample cell 1, it flows out from the outlet 2.

[0036] Preferably, the main structure of the sample cell 1 is a cylindrical structure, and the inlet 3 and outlet 2 are symmetrically arranged on the curved surface of the sample cell 1 to ensure uniform flow of fluid.

[0037] Transparent windows 4 are located on both sides of the sample cell 1, at two planar positions, i.e., on the two bottom surfaces of the cylindrical sample cell 1. Rubber sealing rings 7 are installed between the transparent windows 4 and the sample cell 1 to ensure the airtightness and safety of the sample cell 1. A sample cell cover 5 is installed outside the transparent windows 4. Preferably, the sample cell cover 5 is threaded or snap-fitted to the sample cell 1, preferably using an ordered threaded connection for easy installation and disassembly.

[0038] like Figures 2-3 As shown, transparent solid plastic scintillation particles 8 are filled into sample cell 1. The particle size of the scintillation microspheres can be selected from 1 to 1000 micrometers, preferably 100 micrometers. The scintillation material used in this invention is plastic scintillation microparticles, which have more stable chemical properties. The plastic scintillation particles 8 microspheres are high molecular polymers, which have better chemical stability compared with inorganic materials such as calcium fluoride and GAGG in the prior art, and will not undergo a dissolution reaction in acid solutions. During use, they will not break down and generate fine particles, thus preventing the loss of scintillation material or an increase in column pressure. Radioactive liquid flows in from inlet 3, mixes with solid plastic scintillation particles 8, and excites the solid plastic scintillation particles to generate light signals. The light signals are emitted through transparent window 4 and detected by the matching detection device. Finally, the liquid flows out from outlet 2.

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

[0040] Preferably, the solid plastic scintillation particles 8 are spherical solid particles. The spherical solid particles are regular spheres, which makes the gaps between the particles uniform. The gaps between the particles can be changed by adjusting the radius of the spherical particles, thereby maximizing the mixing reaction between the scintillation particles 8 and the radioactive liquid in the sample cell 1 to generate light signals and improve the detection capability of the sample cell 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 planar positions of the sample cell 1. The transparent window 4 body is more conducive to the transmission of optical signals. The transparent window 4 is arranged between the sample cell 1 and the sample cell cover 5, and is clamped to the side of the sample cell 1 through the connection of the sample cell cover 5 and the sample cell 1.

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

[0043] Preferably, as shown in Figures 2-3 The cylindrical structure is made of white polytetrafluoroethylene material. The cylindrical structure is made into a hollow columnar structure, which is filled with transparent solid plastic scintillating particles 8. When the radioactive liquid flows through, optical signals are generated.

[0044] Preferably, the diameter of the cylindrical structure of the present application can be selected in the range of 0.001 to 1 meter, preferably 6 to 8 centimeters, and the height can be selected 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 the liquid pipeline, and the liquid inlet 3 and the liquid outlet 2 are preferably designed as a pagoda design to facilitate the connection of the liquid pipeline.

[0046] The scintillating material used in the present application is plastic scintillating particles, further, it is transparent plastic scintillating particles in the form of a sphere, which has stable chemical properties. The material is transparent, so the optical signal can be directly output. The present application adopts a planar signal window, which does not need signal collection and other operations. The optical signal can be directly received by a photomultiplier tube, and the optical signal will not be lost. Moreover, the operation is simple and the cost is reduced. Specifically, the sample cell 1 of the present application is used to measure H-3, C-14 and Sr-90 three kinds of nuclides in an 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 part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the present application.

Claims

1. A sample cell for radio liquid scintillation analysis, characterized by, The sample cell, the liquid outlet, the liquid inlet, the transparent window and the sample cell cover; the inner wall of the sample cell is provided with nylon screen gauze, the nylon screen gauze is arranged close to the inner wall of the sample cell, and the nylon screen gauze is 5-30000 mesh screen gauze; The liquid inlet and the liquid outlet are symmetrically arranged on the outer wall of the sample cell, the liquid inlet and the liquid outlet are connected with the inside of the sample cell, radioactive liquid can enter the sample cell through the liquid inlet, and then flow out from the liquid outlet after passing through the inside of the sample cell; The transparent window is arranged on both sides of the sample cell, and a rubber sealing ring is arranged between the transparent window and the sample cell; the sample cell cover is arranged outside the transparent window; The sample cell is filled with solid plastic scintillation particles, the particle size of the solid plastic scintillation particles is 1-1000 microns; radioactive liquid flows into the sample cell from the liquid inlet, mixes with the solid plastic scintillation particles, excites the solid plastic scintillation particles to generate light signals, and the light signals are emitted through the transparent window.

2. A sample cell for the analysis of radioactive liquids by scintillation according to claim 1, characterized in that The sample cell cover is threadedly connected or buckled connected with the sample cell.

3. A sample cell for the analysis of radioactive liquids by scintillation according to claim 1, characterized in that The solid plastic scintillation particles are spherical solid particles.

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

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

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

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

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

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

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

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