Neutron source irradiation device capable of switching gas paths

Abstract

A neutron source irradiation device capable of switching gas paths disclosed by the present invention comprises a gas path switching rotor assembly, a transmission pipeline and a plurality of storage pipelines, the transmission pipeline is provided with an electromagnetic chuck, and a neutron source is stored in each storage pipeline. And the transmission pipeline can be communicated with the different storage pipelines through rotation of the gas path switching rotor assembly, so that neutron sources in the different storage pipelines can reach the electromagnetic chuck through the transmission pipeline. Neutron sources at different positions can be transmitted to the same position for irradiation, an independent transmission irradiation structure is provided, the irradiation position structure is simple, the scattering influence can be reduced, meanwhile, different neutron sources have good repeatability and consistency at the irradiation positions, position adjustment of a measured instrument is not needed, the verification efficiency is improved, and the detection cost is reduced. And the stability and consistency error of the generated neutron radiation field are ensured.

Description

Technical Field

[0001] The invention relates to the technical field of radioactive irradiation equipment, and in particular to a neutron source irradiation device with switchable gas paths. Background Art

[0002] A neutron source is a device that emits neutrons. There are many types of neutron sources, ranging from handheld radioactive sources to research reactors and fission sources at neutron research facilities. Depending on the energy of the neutrons, the neutron flux, and the size of the device, these devices have a wide range of uses in physics, engineering, medicine, nuclear weapons, oil exploration, biology, chemistry, nuclear power, and other industries.

[0003] A neutron source irradiation device is a device that irradiates a neutron source to generate neutrons. In the prior art, the design of neutron source irradiation devices mostly uses a water tank to store the neutron source, and uses a motor-driven wire rope to lift the neutron source to the irradiation position. The prior art neutron source irradiation device has the following problems when in use: 1. In the event of a power outage, the neutron source cannot quickly return to the storage position, posing a major safety hazard; 2. In this way, only one neutron source can be lifted at the same position. When switching between different neutron sources for irradiation, the position of the instrument under test needs to be adjusted, affecting the calibration efficiency of the neutron radiation instrument. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the present invention is: how to provide a neutron source irradiation device with switchable gas paths that ensures that different neutron sources can be switched at the same position when irradiating, without the need to adjust the position of the instrument under test, thereby improving the calibration efficiency.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions: A neutron source irradiation device with switchable gas paths comprises a gas path switching rotor assembly, a transmission pipeline and a plurality of storage pipelines, wherein the transmission pipeline is provided with an electromagnetic suction cup, each of the storage pipelines stores a neutron source, and the gas path switching rotor assembly can rotate to connect the transmission pipeline with different storage pipelines, so that the neutron sources in different storage pipelines can reach the electromagnetic suction cup via the transmission pipeline.

[0006] Preferably, the gas path switching rotor assembly includes a rotor, a rotating shaft and a driving member, wherein the driving member is connected to the rotating shaft to drive the rotating shaft to rotate through the driving member, and the rotating shaft is connected to the rotor to drive the rotor to rotate through the rotating shaft.

[0007] Preferably, an arc-shaped connecting pipe is provided in the rotor, and an opening of the arc-shaped connecting pipe close to one end of the transmission pipe is located in the middle position of the rotor and is adapted to the opening size of the transmission pipe at the corresponding position, and an opening of the arc-shaped connecting pipe close to one end of the storage pipe is located at the edge of the rotor and is adapted to the opening size of the storage pipe at the corresponding position, so that the arc-shaped connecting pipe can be aligned with the outlets of the storage pipes at different positions.

[0008] Preferably, the rotor is made of boron-containing polyethylene material, and a protective sleeve made of stainless steel material is also provided on the outside of the rotor.

[0009] Preferably, a radiation source plug is provided in each of the storage pipes, the neutron source is stored in the radiation source plug, the radiation source plug comprises a radiation source cup and a screw plug, the neutron source is located in the radiation source cup, and the screw plug is connected to the opening of the radiation source cup so that the neutron source can be stored in the radiation source cup through the screw plug.

[0010] Preferably, a heat dissipation structure and a plurality of friction rings are also provided on the outer wall surface of the source cup, the source cup and the screw plug are both made of aluminum, the friction ring is made of copper, and the interior of the source cup and the screw plug has a composite topological structure with different arrangements and combinations of low atomic number materials.

[0011] Preferably, the neutron source irradiation device also includes a gas delivery component, which includes a plurality of gas delivery pipelines corresponding one-to-one to the storage pipelines, and the gas delivery pipelines are connected to the storage pipelines at corresponding positions, and compressed air is introduced into the storage pipelines at corresponding positions through the gas delivery pipelines to drive the source plug and the neutron source to the electromagnetic suction cup by using compressed air.

[0012] Preferably, the neutron source irradiation device also includes a shell, and the gas path switching rotor assembly, storage pipeline and gas transmission pipeline are all located in the shell. The shell is made of boron-containing polyethylene material, and the shell is also covered with an outer shell made of stainless steel material.

[0013] Preferably, a Lenz reducer is sleeved on the transmission pipeline near the arc-shaped connecting pipeline, and the Lenz reducer generates a magnetic field when charged to reduce the speed of the passing source plug by utilizing the Lenz effect.

[0014] Preferably, a mounting seat is further provided in the shell, the mounting seat is made of boron-containing polyethylene material, and the storage pipe is arranged in the mounting seat.

[0015] Compared with the prior art, the present invention has the following advantages: 1. The device switches the rotation of the rotor assembly through the gas path, so that different storage pipes are connected with the transmission pipe, so that the neutron sources in different storage pipes can all reach the electromagnetic suction cup through the transmission pipe, that is, the present invention can transmit neutron sources in different positions to the same position for irradiation, and has an independent transmission and irradiation structure. The irradiation position structure is simple, which can reduce the influence of scattering. At the same time, different neutron sources have good repeatability and consistency at the irradiation position, and there is no need to adjust the position of the measured instrument, which improves the calibration efficiency and ensures the stability and consistency error of the generated neutron radiation field.

[0016] 2. This device uses pneumatic means to push the neutron source and the source plug to move, and uses an electromagnetic suction cup to attract them. When a power outage occurs, the electromagnetic suction cup can automatically release the neutron source when the power is cut off. The neutron source can return to the storage position along the storage pipe under the action of its own weight, thereby ensuring the safe use of the neutron source under special circumstances.

[0017] 3. The driving part of the device is mainly responsible for switching the transmission gas path, thereby reducing the weight of the rotor and reducing the torque of the driving part, ensuring that the driving part can stop automatically when the source is accidentally stuck, thereby preventing damage to the source plug and improving the reliability of the device.

[0018] 4. When the device switches the neutron source, the neutron source itself will not rotate, so there will be no radiation leakage due to the switching of the neutron source, thereby ensuring the accuracy of the standard neutron field.

[0019] 5. This device is made of integral casting of boron-containing polyethylene, and is covered with stainless steel to shield the secondary gamma rays of neutrons. At the same time, the structural rigidity of the entire device is ensured, which can effectively shield the neutron radiation dose. In addition, the rotor gas path switching and pneumatic transmission are combined to ensure that different neutron sources are in the same position when switching irradiation. There is no need to adjust the position of the measured instrument, which improves the verification efficiency. When the system is powered off, the neutron source automatically returns to the safe storage position to ensure the safe irradiation and safe storage of the neutron source. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the appearance structure of the neutron source irradiation device with switchable gas path of the present invention; Figure 2 It is a cross-sectional view of the neutron source irradiation device with switchable gas path of the present invention; Figure 3 It is a schematic diagram of the structure of the neutron source irradiation device with switchable gas path of the present invention after removing the shell; Figure 4 This is a schematic diagram of the structure of the neutron source irradiation device with switchable gas paths of the present invention after removing the shell, the protective cover and the mounting seat; Figure 5It is a schematic structural diagram of a source plug in a neutron source irradiation device with switchable gas path according to the present invention; Figure 6 The figure is a cross-sectional view of a source plug in a neutron source irradiation device with switchable gas paths according to the present invention.

[0021] Explanation of the reference numerals: shell 1, transmission pipeline 2, electromagnetic suction cup 3, arc-shaped connecting pipeline 4, protective cover 5, storage pipeline 6, source plug 7, screw plug 701, source cup 702, friction ring 703, gas transmission pipeline 8, drive motor 9, mounting seat 10, rotor 11, neutron source 12. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment 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. Unless otherwise defined, the technical terms or scientific terms used herein should be the common meaning understood by people with general skills in the field to which the present invention belongs.

[0023] The words "first", "second" and similar words used in the patent application specification and claims of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, unless the context clearly indicates otherwise, the singular forms of "a", "an" or "the" and other similar words do not indicate a quantitative limitation, but indicate the existence of at least one. Words such as "include" or "comprise" mean that the elements or objects appearing before "include" or "comprise" cover the features, wholes, steps, operations, elements and / or components listed after "include" or "comprise", and do not exclude the existence or addition of one or more other features, wholes, steps, operations, elements, components and / or their collections. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0024] The following three aspects also need to be considered when designing a neutron source irradiation device: reduce the overall size and weight of the device as much as possible; the energy and intensity of secondary gamma rays should not be too high; according to the provisions of GB18871-2002 and the average working hours of occupational radiation workers, the radiation dose rate at any point outside the device is required to be less than 25μSv / h.

[0025] In order to meet the above three requirements and solve the problem that only one neutron source can be lifted at the same position in the prior art, a neutron source irradiation device with switchable gas path is provided in this specific embodiment. Figure 1 To the attached Figure 4 As shown, it includes a gas path switching rotor assembly, a transmission pipeline 2 and a plurality of storage pipelines 6. An electromagnetic chuck 3 is provided on the transmission pipeline 2. Neutron sources are stored in each storage pipeline 6. The gas path switching rotor assembly can make the transmission pipeline 2 communicate with different storage pipelines 6 by rotating, so that the neutron sources in different storage pipelines 6 can reach the electromagnetic chuck 3 through the transmission pipeline 2. The electromagnetic chuck 3 is charged to generate suction, so that the neutron source can be fixed to the position, ensuring the stability and repeatability error of the neutron source position. The transmission pipeline 2 is a transmission mechanism for transmitting the neutron source from the storage position to the irradiation position, and its material can be a plastic pipe or an aluminum metal pipe. The storage pipeline 6 can be set with different storage pipelines 6 according to the number of neutron sources, such as 4 storage pipelines in this specific embodiment. The storage pipeline 6 is used to store the neutron source in the storage position to ensure the safe use of the neutron source.

[0026] Specifically, the gas path switching rotor assembly is a structural member that connects the neutron source from the storage pipe 6 to the transmission pipe 2, ensuring that the neutron sources at different storage positions are transmitted from the storage pipe 6 to the transmission pipe 2, thereby driving the neutron source 12 to the irradiation position. The gas path switching rotor assembly includes a rotor 11, a rotating shaft and a driving member, the driving member is connected to the rotating shaft to drive the rotating shaft to rotate through the driving member, and the driving member in this scheme is a motor 9, and the rotating shaft is connected to the rotor 11 to drive the rotor 11 to rotate through the rotating shaft. An arc-shaped connecting pipe 4 is provided in the rotor 11, and the opening of the arc-shaped connecting pipe 4 close to one end of the transmission pipe 2 is located in the middle position of the rotor 11, and is adapted to the opening size of the transmission pipe 2 at the corresponding position, so that the arc-shaped connecting pipe 4 can always correspond to the position of the transmission pipe 2 during the rotation of the rotor 11; the opening of the arc-shaped connecting pipe 4 close to one end of the storage pipe 6 is located at the edge of the rotor 11, and is adapted to the opening size of the storage pipe 6 at the corresponding position, so that the arc-shaped connecting pipe 4 can be aligned with the outlet of the storage pipe 6 at different positions during the rotation. The rotor 11 is made of boron-containing polyethylene material, and a protective cover 5 made of 304 stainless steel material is also set outside the rotor 11. The structure of the boron-containing polyethylene rotor 11 and the external 304 stainless steel can better shield neutron radiation. The size of the rotor 11 is mainly based on the size of the source plug 7, the number of neutron sources 12, etc., and is the optimal size obtained by geometric calculation.

[0027] In this specific embodiment, as shown in the attached Figure 5 and attached Figure 6As shown, a source plug 7 is provided in each storage pipe 6. The source plug 7 is mainly used to store the neutron source 12 and to drive the neutron source 12 to move to the irradiation position by pneumatic means. The source plug 7 includes a source cup 702, a screw plug 701 and a plurality of friction rings 703. The neutron source 12 is located in the source cup 702, and the screw plug 701 is connected to the opening of the source cup 702, so that the neutron source is stored in the source cup 702 through the screw plug 701. Specifically, the screw plug 701 and the source cup 702 are made of aluminum material structure to ensure their mechanical properties. The composite topological structure with different low atomic number material arrangement and combination inside can effectively reduce the backscattering of the neutron tank and the influence of the neutron source gamma photons. The source cup 702 has a heat dissipation structure design to ensure that the excess heat generated by the neutron source is taken away by the gas source, and to ensure that the structural size of the source plug 7 is within a certain range due to thermal expansion and contraction, so that it can move freely in the guide positioning cylinder. The friction ring 703 is sleeved on the outer wall surface of the source cup 702 and is made of wear-resistant copper material, which can play a good wear-resistant role.

[0028] In this specific embodiment, the neutron source irradiation device also includes a gas delivery component, which includes a plurality of gas delivery pipelines 8 corresponding one-to-one to the storage pipelines 6, and the gas delivery pipelines 8 are connected to the storage pipelines 6 at corresponding positions. Compressed air is introduced into the storage pipelines 6 at corresponding positions through the gas delivery pipelines 8, so that the source plug 7 and the neutron source are driven to the electromagnetic suction cup 3 by compressed air.

[0029] In this specific embodiment, the neutron source irradiation device also includes a shell 1, and the gas path switching rotor assembly, the storage pipeline 6 and the gas transmission pipeline 8 are all located in the shell 1. The shell 1 is made of boron-containing polyethylene material, and a shell made of stainless steel material is also provided outside the shell 1. The shell 1 mainly uses boron-containing polyethylene material as a moderated neutron material, and the boron-containing polyethylene is calculated according to the activity of the neutron source, and the outermost layer is an outer box of 304 stainless steel material. The inner boron-containing polyethylene is processed as a whole piece to form a shell 1 shielding structure, ensuring that the dose rate at 5 cm from the outer surface of the source container is ≤2.5μSv / h.

[0030] In this specific embodiment, a Lenz reducer (not shown in the figure) is also provided in the transmission pipeline 2 near the arc-shaped connecting pipeline 4. When the Lenz reducer is energized, it generates a magnetic field to utilize the Lenz effect to slow down the passing radiation source plug 7, thereby reducing the collision with the radiation cup.

[0031] In this specific embodiment, a mounting seat 10 is further provided in the housing 1, and the mounting seat 10 is made of a boron-containing polyethylene material, and the storage pipe 6 is provided in the mounting seat 10. The mounting seat 10 is a boron-containing polyethylene mounting seat 10 with different thicknesses calculated according to the size of the neutron source, and is used to moderate neutron radiation.

[0032] Compared with the prior art, the present device switches the rotation of the rotor assembly through the gas path, so that different storage pipes 6 are connected with the transmission pipe 2, so that the neutron sources 12 in different storage pipes 6 can all pass through the transmission pipe 2 to reach the electromagnetic chuck 3, that is, the present invention can transmit the neutron sources 12 at different positions to the same position for irradiation, and has an independent transmission irradiation structure, the irradiation position structure is simple, and the scattering effect can be reduced. At the same time, different neutron sources 12 have good repeatability and consistency at the irradiation position, and there is no need to adjust the position of the measured instrument, improve the calibration efficiency, and ensure the stability and consistency error of the generated neutron radiation field. The present device uses a pneumatic method to push the neutron source 12 and the source plug 7 to move, and uses the electromagnetic chuck 3 to attract them. When a power outage or the like occurs, the electromagnetic chuck 3 is powered off to automatically release the neutron source 12, and the neutron source 12 can return to the storage position along the storage pipe 6 under the action of its own weight, thereby ensuring the safety of the neutron source 12 in special circumstances. The driving member of the device mainly carries the switching of the transmission gas path, thereby reducing the weight of the rotor 11, thereby reducing the torque of the driving member, ensuring that the driving member can automatically stop when the source is accidentally stuck, thereby preventing damage to the source plug 7 and improving the reliability of the device. When the device switches the neutron source, the neutron source itself will not rotate, so there will be no radiation leakage due to switching the neutron source, thereby ensuring the accuracy of the standard neutron field.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the technical solution. Those skilled in the art should understand that those modifications or equivalent substitutions of the technical solution of the present invention that do not depart from the purpose and scope of the technical solution should be included in the scope of the claims of the present invention.

Claims

1. A neutron source irradiation device with switchable gas path, characterized in that: It includes an air path switching rotor assembly, a transmission pipeline and multiple storage pipelines. The transmission pipeline is provided with an electromagnetic suction cup. Each storage pipeline stores a neutron source. The air path switching rotor assembly can connect the transmission pipeline with different storage pipelines by rotating, so that the neutron sources in different storage pipelines can reach the electromagnetic suction cup through the transmission pipeline.

2. The neutron source irradiation device with switchable gas path according to claim 1, characterized in that: The gas path switching rotor assembly includes a rotor, a rotating shaft and a driving member, wherein the driving member is connected to the rotating shaft so as to drive the rotating shaft to rotate through the driving member, and the rotating shaft is connected to the rotor so as to drive the rotor to rotate through the rotating shaft.

3. The neutron source irradiation device with switchable gas path according to claim 2, characterized in that: An arc-shaped connecting pipe is provided in the rotor, and an opening of the arc-shaped connecting pipe close to one end of the transmission pipe is located in the middle position of the rotor and is adapted to the opening size of the transmission pipe at the corresponding position. An opening of the arc-shaped connecting pipe close to one end of the storage pipe is located at the edge of the rotor and is adapted to the opening size of the storage pipe at the corresponding position, so that the arc-shaped connecting pipe can be aligned with the outlets of the storage pipes at different positions.

4. The neutron source irradiation device with switchable gas path according to claim 3, characterized in that: The rotor is made of boron-containing polyethylene material, and a protective sleeve made of stainless steel material is sleeved on the outside of the rotor.

5. The neutron source irradiation device with switchable gas path according to claim 4, characterized in that: A radiation source plug is provided in each storage pipe. The neutron source is stored in the radiation source plug. The radiation source plug comprises a radiation source cup and a screw plug. The neutron source is located in the radiation source cup, and the screw plug is connected to the opening of the radiation source cup so that the neutron source can be stored in the radiation source cup through the screw plug.

6. The neutron source irradiation device with switchable gas path according to claim 5, characterized in that: A heat dissipation structure and a plurality of friction rings are also provided on the outer wall surface of the radiation source cup. The radiation source cup and the screw plug are both made of aluminum, and the friction ring is made of copper. The interiors of the radiation source cup and the screw plug are provided with a composite topological structure with different arrangements and combinations of low atomic number materials.

7. The neutron source irradiation device with switchable gas path according to claim 6, characterized in that: The neutron source irradiation device also includes a gas delivery component, which includes a plurality of gas delivery pipelines corresponding one-to-one to the storage pipelines, and the gas delivery pipelines are connected to the storage pipelines at corresponding positions. Compressed air is introduced into the storage pipelines at corresponding positions through the gas delivery pipelines, so that the source plug and the neutron source are driven to the electromagnetic suction cup by compressed air.

8. The neutron source irradiation device with switchable gas path according to claim 7, characterized in that: The neutron source irradiation device also includes a shell, the gas path switching rotor assembly, the storage pipeline and the gas transmission pipeline are all located in the shell, the shell is made of boron-containing polyethylene material, and the shell is also covered with an outer shell made of stainless steel material.

9. The neutron source irradiation device with switchable gas path according to claim 8, characterized in that: A Lenz reducer is also sleeved on the transmission pipeline near the arc-shaped connecting pipeline. The Lenz reducer generates a magnetic field when charged to reduce the speed of the passing source plug by utilizing the Lenz effect.

10. The neutron source irradiation device with switchable gas path according to claim 9, characterized in that: A mounting seat is also provided in the shell, the mounting seat is made of boron-containing polyethylene material, and the storage pipe is arranged in the mounting seat.

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