Reference radiation field system of accelerator R-F radiation substance and construction method

Abstract

The invention discloses a reference radiation field system of an accelerator R-F radiation substance and a construction method, and the system comprises an accelerator which is used for generating incident protons; the CaF2 target material is fixed in the direction perpendicular to the proton incidence direction, the experiment positioning system is arranged in the direction with the included angle of 0 degree in the proton incidence direction, the starting point of the experiment positioning system is located at the lower end of the CaF2 target material, the total stroke length is 5 m, and the experiment positioning system has the front-back, left-right, up-down and rotary movement functions; the dose rate selection module is used for carrying out R-F radiation substance low-energy pollution photon research in an area which is 0-1m away from the CaF2 target material, and selecting a dose rate value in a range of 1 [mu] Sv / h-1mSv / h in an area which is 1-5m away from the CaF2 target material according to an inverse proportion attenuation relation of a high-energy photon radiation dose rate along with the square of the distance; the first movable lifting positioning table is used for placing a sample and enabling the irradiated center position of the sample and an accelerator beam to be at the same height through lifting adjustment; the CaF2 target material, the experiment positioning system and the first movable lifting positioning table are all arranged in the target chamber.

Description

Technical Field

[0001] This invention relates to the field of radiation field construction, specifically to a reference radiation field system and construction method for accelerator RF radiation quality. Background Technology

[0002] The construction of a high-energy photon reference radiation field has significant social implications. It provides crucial testing conditions for radiation protection-grade monitoring instruments and personnel protective equipment. Furthermore, the fundamental research conducted at the Tito high-energy photon field serves as the basis for the formulation of radiation protection-related standards and specifications. In addition, the accelerator's high-energy photon radiation field can conduct research on photon-particle interactions, verifying and refining particle physics theories, and providing crucial data support for fundamental scientific theories and even astrophysics.

[0003] The test conditions for RF reference radiation quality recommended in ISO 4037-1:2019 only provide the approximate range of radiation field generation conditions and air kerma rate, and do not clearly provide the construction and use methods of the reference radiation field system based on this radiation quality, which is difficult to meet the construction and operation requirements of RF reference radiation fields. Summary of the Invention

[0004] To achieve the above and other related objectives, this invention discloses a reference radiation field system for accelerator RF radiation quality, comprising: Accelerators are used to produce incident protons; A CaF2 target is fixed along a direction perpendicular to the proton incident direction. When the proton is incident on the CaF2 target, based on... 19 F(p,αγ) 16 The O reaction generates a high-energy photon radiation field of RF radiation quality; An experimental positioning system is set in a direction with an angle of 0° along the incident direction of the protons. The starting point of the experimental positioning system is located at the lower end of the CaF2 target material, and the total travel length is 5m. It has forward, backward, left, right, up, down, and rotational movement functions. It is used to conduct low-energy contamination photon research on RF radiation quality in a region of 0~1m away from the CaF2 target material, and to select a dose rate value in the range of 1μSv / h~1mSv / h in a region of 1m~5m away from the CaF2 target material based on the inverse square attenuation relationship of high-energy photon radiation dose rate with distance. The first movable lifting and positioning platform is set at a position with a radius of 1m centered on the center of the CaF2 target material. The line connecting the position and the center of the circle makes an angle of 45° with the proton incident direction. It is used to place the sample and adjust the lifting and lowering to make the irradiated center of the sample at the same height as the accelerator beamline. The target chamber, in which the CaF2 target, the experimental positioning system, and the first movable lifting positioning platform are all located, is located.

[0005] Preferably, the energy of the proton is 0.872 MeV, 2.05 MeV or 2.7 MeV, and the beam intensity of the proton is 0.1 μA to 15 μA.

[0006] Preferably, the thickness of the CaF2 target is 18μm~22μm.

[0007] Preferably, the dose rate at the location of the first movable lifting and positioning platform is controlled at 1 mSv / h or higher by adjusting the beam intensity of the protons.

[0008] Preferably, the system includes operational monitoring equipment, including a GM detector and a NaI detector, wherein the GM detector is used to monitor the site dose rate in real time, and the NaI detector is used to monitor the site photon energy in real time.

[0009] Preferred, including: The second movable lifting and positioning platform is positioned with the center of the CaF2 target as the center. The line connecting the position of the second movable lifting and positioning platform and the center of the circle makes an angle of 22.5° with the proton incident direction. The operation monitoring equipment is placed on the second movable lifting and positioning platform. The second movable lifting and positioning platform is adjusted by lifting to make the irradiated center position of the operation monitoring equipment at the same height as the accelerator beamline, and the second movable lifting and positioning platform is located in the target chamber.

[0010] Preferably, the distance between the target chamber and the surrounding walls is more than 5m.

[0011] Secondly, this invention discloses a method for constructing a reference radiation field system for accelerator RF radiation quality, comprising: Incident protons are generated using an accelerator, and the energy of the protons is controlled to be 0.872 MeV, 2.05 MeV, or 2.7 MeV, with a beam current intensity of 0.1 μA to 15 μA. These protons are then incident on a CaF2 target with a thickness of 20 μm. 19 F(p,αγ) 16 The O reaction generates a high-energy photon radiation field of RF radiation quality; The CaF2 target is fixed along a direction perpendicular to the proton incident direction; All measurement points were set outside a semi-circular area with a radius of 1m centered on the center of the CaF2 target material; An experimental positioning system is arranged along a direction with an angle of 0° to the proton incident direction. The starting point of the experimental positioning system is located at the lower end of the CaF2 target, and the total travel length is 5m. The area 0~1m away from the CaF2 target is used for the study of low-energy contamination photons of RF radiation quality, and the area 1m~5m away from the CaF2 target is used to select dose rate values ​​in the range of 1μSv / h~1mSv / h based on the inverse square attenuation relationship of high-energy photon radiation dose rate with distance. A first movable lifting and positioning platform is set in a direction with the center of the CaF2 target material as the center, a radius of 1m, and an angle of 45° with the proton incident direction. By adjusting the lifting and lowering of the first movable lifting and positioning platform, the irradiated center position of the sample placed on its platform is at the same height as the accelerator beamline. An operation monitoring device is arranged in a direction that makes an angle of 22.5° with the proton incident direction. The operation monitoring device includes a GM detector and a NaI detector. The operation monitoring device is placed on a second movable lifting and positioning platform. By adjusting the lifting and lowering of the second movable lifting and positioning platform, the irradiation center of the operation monitoring device is at the same height as the accelerator beamline. The CaF2 target, experimental positioning system, first movable lifting positioning platform, operation monitoring equipment and second movable lifting positioning platform are set in the target chamber, and the distance between the target chamber and the surrounding walls is controlled to be more than 5m.

[0012] By adopting the above technical solution, the system layout and construction method of the accelerator RF radiation quality reference field are clarified. The required radiation field is generated by using specific reactions. The target fixing method, measurement point position, experimental positioning system and monitoring equipment layout are reasonably set, and the distance between the target chamber and the surrounding walls is controlled. This effectively reduces the dose rate contribution of low-energy contamination photons, flexibly obtains different dose rate values ​​to meet various functional requirements, and ensures the stability and accuracy of the radiation field. It not only meets the relevant standard recommendations, but also meets the construction and operation requirements of the RF reference radiation field, providing reliable reference radiation field conditions for applications such as radiation monitoring instrument metrological verification and site dose rate survey. Attached Figure Description

[0013] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. The drawings are provided for a better understanding of the invention and are not intended to limit the scope of this disclosure. In the drawings, the same or similar reference numerals denote the same or similar elements, wherein: Figure 1 This is an overall schematic diagram of an embodiment of the present invention.

[0014] Reference numerals in the attached figures: 1. First movable lifting and positioning platform; 2. Second movable lifting and positioning platform; 3. Experimental positioning system. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] Reference Figure 1 This invention provides a reference radiation field system for accelerator RF radiation quality, characterized in that it includes: Accelerators are used to produce incident protons; A CaF2 target is fixed along a direction perpendicular to the proton incident direction. When the proton is incident on the CaF2 target, based on... 19 F(p,αγ) 16 The O reaction generates a high-energy photon radiation field of RF radiation quality; The experimental positioning system 3 is set in the direction with an angle of 0° along the incident direction of the protons. The starting point of the experimental positioning system 3 is located at the lower end of the CaF2 target material, and the total travel length is 5m. It has forward, backward, left and right, up and down, and rotational movement functions. It is used to conduct low-energy contamination photon research on RF radiation quality in the area 0~1m away from the CaF2 target material, and to select a dose rate value in the range of 1μSv / h~1mSv / h in the area 1m~5m away from the CaF2 target material according to the inverse square attenuation relationship of high-energy photon radiation dose rate with distance. The first movable lifting and positioning platform 1 is set in a direction with the center of the CaF2 target material as the center, a radius of 1m, and an angle of 45° with the proton incident direction. It is used to place the sample and adjust the lifting and lowering to make the irradiated center of the sample at the same height as the accelerator beamline. The system operates monitoring equipment, including a GM detector and a NaI detector, wherein the GM detector is used to monitor the site dose rate in real time, and the NaI detector is used to monitor the site photon energy in real time. The second movable lifting and positioning platform 2 is set in a direction with an angle of 22.5° to the proton incident direction. The operation monitoring equipment is placed on the second movable lifting and positioning platform 2. The second movable lifting and positioning platform 2 is adjusted by lifting so that the irradiated center position of the operation monitoring equipment is at the same height as the accelerator beamline, and the second movable lifting and positioning platform 2 is located in the target chamber. The target chamber contains the CaF2 target, the experimental positioning system 3, the first movable lifting positioning platform 1, the operation monitoring equipment, and the second movable lifting positioning platform 2.

[0017] Preferably, the energy of the protons produced by the accelerator is 0.872 MeV, 2.05 MeV or 2.7 MeV, the beam intensity of the protons is 0.1 μA to 15 μA, and the thickness of the CaF2 target is 18 μm to 22 μm. In this embodiment of the invention, the CaF2 thickness is preferably 20 μm.

[0018] The above describes the use of protons, incident particles generated by an accelerator, at specific energies (0.872 MeV, 2.05 MeV, and 2.7 MeV), when these protons are incident on a CaF2 target substrate of approximately 20 μm at beam current intensities of 0.1 μA to 15 μA. Based on... 19 F(p,αγ) 16 The O reaction is a fundamental condition for the generation of a high-energy photon radiation field that can construct RF radiation quality.

[0019] Considering the applicability of target materials other than RF radiation materials, a vertical incidence method should be adopted, fixing the CaF2 target material along a direction perpendicular to the accelerator particle incident direction.

[0020] because 19 F(p,αγ) 16 The O reaction will be accompanied by low-energy photons (energy below 1 MeV), and the accelerator incident protons bombarding parts outside the target will also excite low-energy photons. These low-energy photons are a component of the contamination radiation in the RF radiation field, and their dose rate contribution should be minimized. Therefore, all measurement points should be outside a semi-circular area with a radius of 1 m centered on the target.

[0021] because 19 F(p,αγ) 16 The high-energy photon radiation of the O-response exhibits anisotropy; that is, with the target center as the center and for the same radius, the obtained high-energy photon dose rate is closely related to the angle between the target and the 0° direction, and the maximum dose rate occurs at an angle of 45°. Therefore, the structural arrangement of the measurement points and radiation field should be flexibly changed according to specific functional requirements.

[0022] A first movable lifting and positioning platform 1 is placed with the target center as the center, a radius of 1m, and an included angle of 45°. The lifting function enables samples of different volumes to be placed on the platform, and by adjusting the height, the irradiation center of the sample is ensured to be at the same height as the accelerator beamline. The maximum dose rate value of the RF radiation quality can be obtained at this point, typically a dose rate of 1mSv / h or higher, which is obtained by adjusting the proton beam intensity of the accelerator.

[0023] according to19 F(p,αγ) 16 Based on the anisotropic distribution characteristics of high-energy photon radiation from the O reaction, the location with the smallest dose rate fluctuation as the angle changes, namely 22.5°, is selected to set up the RF radiation field operation monitoring equipment. GM detectors can be used for real-time monitoring of the site dose rate, and NaI detectors can be used for real-time monitoring of the site photon energy. The detectors are placed on the second movable lifting and positioning platform 2, and the position of the irradiated center of the detector is adjusted up and down to ensure that it is at the same height as the accelerator beamline.

[0024] Preferably, in this embodiment of the invention, two second movable lifting positioning platforms 2 are provided, and the two second movable lifting positioning platforms 2 are symmetrically arranged with the proton incident direction as the center line. The two movable lifting positioning platforms are respectively used to install the GM detector and the NaI detector.

[0025] High-energy photon radiation can cause air ionization and generate a large amount of high-energy electron radiation. In order to avoid the electron radiation from colliding with the walls, ground and other surfaces in the surrounding environment and generating bremsstrahlung photons that could contaminate the target's high-energy photon reference radiation, it is necessary to ensure that the target chamber is at least 5 meters away from the surrounding walls.

[0026] In a preferred embodiment, the present invention provides a method for constructing a reference radiation field system for accelerator RF radiation quality, the reference radiation field system comprising: Incident protons are generated using an accelerator, and the energy of the protons is controlled to be 0.872 MeV, 2.05 MeV, or 2.7 MeV, with a beam current intensity of 0.1 μA to 15 μA. These protons are then incident on a CaF2 target with a thickness of 20 μm. 19 F(p,αγ) 16 The O reaction generates a high-energy photon radiation field of RF radiation quality; The CaF2 target is fixed along a direction perpendicular to the proton incident direction; All measurement points were set outside a semi-circular area with a radius of 1m centered on the center of the CaF2 target material; An experimental positioning system 3 is arranged along a direction with an angle of 0° to the proton incident direction. The starting point of the experimental positioning system 3 is located at the lower end of the CaF2 target, and the total travel length is 5m. The area 0~1m away from the CaF2 target is used for the study of low-energy contamination photons of RF radiation quality, and the area 1m~5m away from the CaF2 target is used to select a dose rate value in the range of 1μSv / h~1mSv / h based on the inverse square attenuation relationship of high-energy photon radiation dose rate with distance. A first movable lifting and positioning platform 1 is set in a direction with the center of the CaF2 target material as the center, a radius of 1m, and an angle of 45° with the proton incident direction. By adjusting the lifting and lowering of the first movable lifting and positioning platform 1, the irradiated center position of the sample placed on its platform is at the same height as the accelerator beamline. An operation monitoring device is arranged in a direction that makes an angle of 22.5° with the proton incident direction. The operation monitoring device includes a GM detector and a NaI detector. The operation monitoring device is placed on a second movable lifting and positioning platform 2. By adjusting the lifting and lowering of the second movable lifting and positioning platform 2, the irradiated center position of the operation monitoring device is at the same height as the accelerator beamline. The CaF2 target, experimental positioning system 3, first movable lifting positioning platform 1, operation monitoring equipment and second movable lifting positioning platform 2 are set in the target chamber, and the distance between the target chamber and the surrounding walls is controlled to be more than 5m.

[0027] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the meaning consistent with their meaning in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined.

[0028] For the sake of simplicity, the method embodiments are described as a series of actions. However, those skilled in the art should understand that the embodiments of the present invention are not limited to the described order of actions, because according to the embodiments of the present invention, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions involved are not necessarily essential to the embodiments of the present invention.

[0029] As can be seen from the above description of the embodiments, those skilled in the art can clearly understand that this application can be implemented by means of software plus necessary general-purpose hardware platforms. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in various embodiments or some parts of the embodiments of this application.

[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A reference radiation field system for accelerator RF radiation quality, characterized in that, include: Accelerators are used to produce incident protons; A CaF2 target is fixed along a direction perpendicular to the proton incident direction. When the proton is incident on the CaF2 target, based on... 19 F(p,αγ) 16 The O reaction generates a high-energy photon radiation field of RF radiation quality; An experimental positioning system is set in a direction with an angle of 0° along the incident direction of the protons. The starting point of the experimental positioning system is located at the lower end of the CaF2 target material, and the total travel length is 5m. It has forward, backward, left, right, up, down, and rotational movement functions. It is used to conduct low-energy contamination photon research on RF radiation quality in a region of 0~1m away from the CaF2 target material, and to select a dose rate value in the range of 1μSv / h~1mSv / h in a region of 1m~5m away from the CaF2 target material based on the inverse square attenuation relationship of high-energy photon radiation dose rate with distance. The first movable lifting and positioning platform is set at a position with a radius of 1m centered on the center of the CaF2 target material. The line connecting the position and the center of the circle makes an angle of 45° with the proton incident direction. It is used to place the sample and adjust the lifting and lowering to make the irradiated center of the sample at the same height as the accelerator beamline. The target chamber, in which the CaF2 target, the experimental positioning system, and the first movable lifting positioning platform are all located, is located.

2. The system according to claim 1, characterized in that, The protons have energies of 0.872 MeV, 2.05 MeV, or 2.7 MeV, and the proton beam intensity is 0.1 μA to 15 μA.

3. The system according to claim 1, characterized in that, The thickness of the CaF2 target is 18μm~22μm.

4. The system according to claim 1, characterized in that, The dose rate at the location of the first movable lifting and positioning platform is controlled at 1 mSv / h or higher by adjusting the beam intensity of the protons.

5. The system according to claim 1, characterized in that, The system includes operational monitoring equipment, including a GM detector and a NaI detector. The GM detector is used to monitor the site dose rate in real time, and the NaI detector is used to monitor the site photon energy in real time.

6. The system according to claim 5, characterized in that, include: The second movable lifting and positioning platform is positioned with the center of the CaF2 target as the center. The line connecting the position of the second movable lifting and positioning platform and the center of the circle makes an angle of 22.5° with the proton incident direction. The operation monitoring equipment is placed on the second movable lifting and positioning platform. The second movable lifting and positioning platform is adjusted by lifting to make the irradiated center position of the operation monitoring equipment at the same height as the accelerator beamline, and the second movable lifting and positioning platform is located in the target chamber.

7. The system according to claim 1, characterized in that, The target chamber is more than 5 meters away from the surrounding walls.

8. A method for constructing a reference radiation field system for accelerator RF radiation quality, characterized in that, The reference radiation field system according to any one of claims 1 to 7 comprises: Incident protons are generated using an accelerator, and the energy of the protons is controlled to be 0.872 MeV, 2.05 MeV, or 2.7 MeV, with a beam current intensity of 0.1 μA to 15 μA. These protons are then incident on a CaF2 target with a thickness of 20 μm. 19 F(p,αγ) 16 The O reaction generates a high-energy photon radiation field of RF radiation quality; The CaF2 target is fixed along a direction perpendicular to the proton incident direction; All measurement points were set outside a semi-circular area with a radius of 1m centered on the center of the CaF2 target material; An experimental positioning system is arranged along a direction with an angle of 0° to the proton incident direction. The starting point of the experimental positioning system is located at the lower end of the CaF2 target, and the total travel length is 5m. The area 0~1m away from the CaF2 target is used for the study of low-energy contamination photons of RF radiation quality, and the area 1m~5m away from the CaF2 target is used to select dose rate values ​​in the range of 1μSv / h~1mSv / h based on the inverse square attenuation relationship of high-energy photon radiation dose rate with distance. A first movable lifting and positioning platform is set in a direction with the center of the CaF2 target material as the center, a radius of 1m, and an angle of 45° with the proton incident direction. By adjusting the lifting and lowering of the first movable lifting and positioning platform, the irradiated center position of the sample placed on its platform is at the same height as the accelerator beamline. An operation monitoring device is arranged in a direction that makes an angle of 22.5° with the proton incident direction. The operation monitoring device includes a GM detector and a NaI detector. The operation monitoring device is placed on a second movable lifting and positioning platform. By adjusting the lifting of the second movable lifting and positioning platform, the irradiation center of the operation monitoring device is at the same height as the accelerator beamline. The CaF2 target, experimental positioning system, first movable lifting positioning platform, operation monitoring equipment and second movable lifting positioning platform are set in the target chamber, and the distance between the target chamber and the surrounding walls is controlled to be more than 5m.

Images