Structure and method for reducing noise of electron accelerator
By using scanning drift tubes and scanning magnets with high resistivity materials in electronic accelerators, the eddy current loss and the magnetic field penetration performance are reduced, and the problem of high noise in low energy state is solved, which effectively reduces noise and protects the health of operators is achieved. .
Patent Information
- Application Number
- CN202010424810.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2020-05-19
- Publication Date
- 2024-12-13
- Estimated Expiration
- 2040-05-19
AI Technical Summary
Industrial electronic accelerators produce large noise in low energy states, existing noise isolation methods are large in size and costly, or sound-absorbing materials are rapidly damaged in high corrosion environments, making it difficult to effectively reduce noise.
Scan drift tubes made of high resistivity vacuum material and scan magnets are installed outside or inside it. By reducing eddy current losses and improving magnetic field penetration performance, the scanning frequency of electron beams and beam spot diameters are increased, thereby reducing air expansion and Noise generation.
Without changing the electronic accelerator structure and not adding large noise reduction isolation covers or sound-absorbing materials, the noise level is significantly reduced, the operator's health is protected, and the material has good corrosion resistance.
Smart Images
Figure CN113692102B_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of electron accelerators, and in particular relates to a structure and method for reducing noise of an electron accelerator. Background Art
[0002] Industrial electron accelerators accelerate electron beams in a vacuum and scan and expand them into a ribbon-shaped electron beam, which then enters the atmosphere through an extraction window to irradiate items. When the electron beam generated by the electron accelerator is not scanned and expanded, the beam spot diameter is 5 to 20 mm, and the scanning frequency is tens of Hz to hundreds of Hz. Because there is a support grid on the extraction window, the electron beam is cut into discontinuously distributed small beams when passing through the support grid. Each small beam independently heats the local air it passes through, causing it to expand instantly and generate noise. The greater the electron beam current, the lower the electron beam energy, the smaller the beam spot, the more energy injected into a unit volume of air per unit time, the more violent the air expansion, and the greater the noise generated. When a low-energy, high-beam electron accelerator is in operation, the noise around the equipment may exceed 100 decibels, seriously affecting the health of the operator. Normally, in order to reduce the noise generated by the electron accelerator during operation, a noise isolation cover is used to separate the electron accelerator from the surrounding environment. However, this method is bulky and expensive. Another conventional method is to add sound-absorbing materials and structures inside the electron accelerator irradiation room and channels. However, the radiation intensity of the accelerator irradiation room and the maze channel is high, the ozone concentration is high, and the corrosiveness is strong. Conventional sound-absorbing materials are quickly damaged and become ineffective. Therefore, a new method is urgently needed to solve this problem. Summary of the invention
[0003] An object of the present invention is to solve at least the above problems and / or disadvantages and to provide at least the advantages which will be described hereinafter.
[0004] In order to achieve these objects and other advantages according to the present invention, a structure for reducing electron accelerator noise is provided, comprising:
[0005] A scanning drift tube, the interior of which is hollow and in a vacuum environment, a lead-out box is provided at the bottom end of the scanning drift tube, a support grid is provided at the end of the lead-out box away from the scanning drift tube, and a window film is provided outside the support grid;
[0006] A scanning magnet for scanning and expanding the electron beam inside the scanning drift tube is arranged outside or inside the scanning drift tube. After passing through the scanning magnet, the electron beam is expanded from a point-shaped electron beam to a strip-shaped electron beam, and is blocked by a supporting grid and divided into multiple small beam clusters that pass through a window film and enter the air.
[0007] Preferably, the scanning drift tube is a scanning drift tube made of a vacuum material with high resistivity.
[0008] Preferably, the high resistivity vacuum material is one of ceramic, glass, nylon, organic glass, polytetrafluoroethylene, and polysulfone, and its resistivity is greater than 10 5 Ω·m, thickness is 5~30mm.
[0009] Preferably, the beam spot diameter of the electron beam on the window film is 5 mm to 80 mm.
[0010] Preferably, the operating frequency of the scanning magnet is 0.5kHz to 40kHz.
[0011] The present invention also provides a method for reducing electron accelerator noise, comprising:
[0012] A high-resistivity scanning drift tube is arranged at the output end of the electron accelerator, and a scanning magnet is arranged outside or inside the scanning drift tube; the high-resistivity scanning drift tube reduces the eddy current loss caused by the scanning magnetic field, improves the scanning magnetic field penetration performance, reduces the heating of the scanning drift tube, greatly increases the scanning frequency of the electron beam, speeds up the scanning movement of the electron beam, and can further increase the electron beam spot diameter, so that the energy injected into the unit volume of air per unit time is reduced, the degree of local air expansion due to heat is reduced, and the noise generated is reduced, thereby reducing the noise generated when the electron accelerator is running.
[0013] The present invention has at least the following beneficial effects:
[0014] The method for reducing the noise of an electron accelerator of the present invention reduces the eddy current loss caused by the scanning magnetic field, improves the penetration performance of the high-frequency scanning magnetic field, reduces the heat generation of the scanning drift tube, and greatly increases the scanning frequency of the electron beam, without changing the structure of the existing electron accelerator, without adding a large noise reduction isolation cover, and without adding sound absorbing materials and sound absorbing structures inside the electron accelerator. After the scanning frequency is increased, the speed of the electron beam scanning movement is accelerated, the energy injected into the unit volume of air per unit time is reduced, the degree of local air expansion due to heat is reduced, and the generated noise is reduced, thereby reducing the noise generated when the electron accelerator is running, and ensuring that the body of the operator is not damaged by the noise.
[0015] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 A schematic diagram of the structure of a device provided by the present invention in which the scanning magnet is located outside the scanning drift tube;
[0017] Figure 2A schematic diagram of the structure of a device in which a scanning magnet provided by the present invention is located in a scanning drift tube;
[0018] Figure 3 This is a partially enlarged schematic diagram of the support grille and window film provided by the present invention. DETAILED DESCRIPTION
[0019] The present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.
[0020] It should be understood that terms such as “having”, “including” and “comprising” used herein do not specify the existence or addition of one or more other elements or combinations thereof.
[0021] like Figure 1-3 A structure for reducing noise of an electron accelerator is shown, comprising:
[0022] A scanning drift tube 1, which is hollow inside and in a vacuum environment, is provided with an outlet box 2 at the bottom end of the scanning drift tube 1, and a support grid 3 is provided at the end of the outlet box 2 away from the scanning drift tube 1, and a window film 4 is provided outside the support grid 3;
[0023] The scanning magnet 5 for scanning and expanding the electron beam inside the scanning drift tube 1 is arranged outside or inside the scanning drift tube 1. The electron beam 6 is expanded from a point-shaped electron beam to a strip-shaped electron beam after passing through the scanning magnet 5, and is blocked by the supporting grid 3, divided into multiple small beam clusters, and passes through the window film 4 into the air.
[0024] Working principle: When the electron accelerator is working, the electron gun (not shown) generates an electron beam 6, and the electron beam 6 is accelerated through the acceleration tube 101 connected to the upper end of the scanning drift tube 1. The accelerated electron beam 6 moves to the bottom end of the acceleration tube 101 and enters the scanning drift tube 1. At the same time, the scanning magnet 5 arranged outside or inside the scanning drift tube 1 scans and expands, and the point-like electron beam is expanded into a strip-like electron beam, and moves downward. Through the lead-out box 2, after being shielded by the support grid 3, it is divided into multiple small beams and passes through the window film 4 into the air; the scanning drift tube 1 is set up to reduce the eddy current loss caused by the scanning magnetic field 5, improve the scanning magnetic field penetration performance, reduce the heat generation of the scanning drift tube, greatly increase the scanning frequency of the electron beam, speed up the scanning movement speed of the electron beam, and further increase the electron beam spot diameter, so that the energy injected into the unit volume of air per unit time is reduced, the degree of local air expansion due to heat is reduced, and the noise generated is reduced, thereby reducing the noise generated during the operation of the electron accelerator. When the scanning magnet is arranged inside the scanning drift tube, the scanning magnetic field generated by the scanning magnet directly acts on the point electron beam passing through the middle of the scanning magnet without obstruction, expanding the point electron beam into a strip electron beam, and the effect of expanding the electron beam is better.
[0025] In the above technical solution, the scanning drift tube 1 is a scanning drift tube made of a vacuum material with a high resistivity. In this way, eddy current loss is the loss caused by the induced current of the scanning magnet, and when the induced voltage remains unchanged, increasing the value of the resistance can reduce the value of the induced current, thereby reducing the eddy current loss. When the physical properties such as the shape remain unchanged, one of the methods to increase the resistance value is to use a material with a large resistivity. Therefore, a scanning drift tube made of a vacuum material with a high resistivity can greatly reduce the eddy current loss caused by the scanning magnetic field, improve the high-frequency scanning magnetic field penetration performance, reduce the heating of the scanning drift tube, and can greatly increase the scanning frequency of the electron beam.
[0026] In the above technical solution, the high resistivity vacuum material is one of ceramic, glass, nylon, organic glass, polytetrafluoroethylene, and polysulfone, and its resistivity is greater than 10 5 Ω·m, thickness is 5~30mm.
[0027] In the above technical solution, the beam spot diameter of the electron beam 6 on the window film 4 is 5 mm to 80 mm. In this way, since the larger the beam spot diameter of the electron beam, the less energy is injected into the unit volume of air per unit time, the degree of local air expansion due to heat will be weakened, thereby reducing the noise generated, thereby reducing the noise generated during the operation of the electron accelerator.
[0028] In the above technical solution, the working frequency of the scanning magnet 5 is: 0.5kHz~40kHz. In this way, the scanning frequency of the magnet is 0.5kHz~40kHz, which can meet the use requirements of the electron accelerator and ensure that the point electron beam can be expanded into a strip electron beam. This type of scanning magnet is widely used in television picture tubes, with relatively mature technology and low cost.
[0029] A method for reducing electron accelerator noise, comprising:
[0030] A high-resistivity scanning drift tube is arranged at the output end of the electron accelerator, and a scanning magnet is arranged outside or inside the scanning drift tube; the high-resistivity scanning drift tube reduces the eddy current loss caused by the scanning magnetic field, improves the scanning magnetic field penetration performance, reduces the heating of the scanning drift tube, greatly increases the scanning frequency of the electron beam, speeds up the scanning movement of the electron beam, and can further increase the electron beam spot diameter, so that the energy injected into the unit volume of air per unit time is reduced, the degree of local air expansion due to heat is reduced, and the noise generated is reduced, thereby reducing the noise generated when the electron accelerator is running.
[0031] The number of devices and processing scales described here are used to simplify the description of the present invention. The application, modification and variation of the structure and method for reducing electron accelerator noise of the present invention will be obvious to those skilled in the art.
[0032] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.
Claims
1. A structure for reducing electron accelerator noise, characterized in that: include: A scanning drift tube, the interior of which is hollow and in a vacuum environment, a lead-out box is provided at the bottom end of the scanning drift tube, a support grid is provided at the end of the lead-out box away from the scanning drift tube, and a window film is provided outside the support grid; A scanning magnet for scanning and expanding the electron beam inside the scanning drift tube, which is arranged outside or inside the scanning drift tube. After passing through the scanning magnet, the electron beam is expanded from a point-shaped electron beam to a strip-shaped electron beam, and is shielded by the support grid and is divided into a plurality of small beam clusters, which pass through the window film and enter the air; The scanning drift tube is a scanning drift tube made of a high-resistivity vacuum material, and the high-resistivity vacuum material is one of ceramic, glass, nylon, organic glass, polytetrafluoroethylene, and polysulfone, and the resistivity of the vacuum material is greater than 10 5 , the thickness is 5~30mm, the working frequency of the scanning magnet is: 0.5kHz~40kHz, and the beam spot diameter of the electron beam on the window film is 5mm~80mm; The invention discloses a structure for reducing electron accelerator noise and a method for reducing electron accelerator noise, comprising: arranging a high-resistivity scanning drift tube at the output end of the electron accelerator, and arranging a scanning magnet outside or inside the scanning drift tube; reducing eddy current loss caused by a scanning magnetic field by the high-resistivity scanning drift tube, improving the scanning magnetic field penetration performance, reducing the heating of the scanning drift tube, greatly increasing the scanning frequency of the electron beam, accelerating the scanning movement speed of the electron beam, and further increasing the electron beam spot diameter, so that the energy injected into the unit volume of air per unit time is reduced, the degree of local air expansion due to heat is reduced, and the noise generated is reduced, thereby reducing the noise generated when the electron accelerator is running.