Maintenance method of electron gun

Abstract

The invention relates to a maintenance method of an electronic gun, the electronic gun comprises a cable connecting part, and the maintenance method comprises the following steps: taking down a cable in the cable connecting part from the electronic gun; the cable is connected to the electronic gun again; mounting an encapsulation mold around the cable connecting part; sealing the potting mold with a sealing member around the cable connection portion while leaving an open potting hole in the upper side of the potting mold; and pouring a filling and sealing liquid into the filling and sealing mold through the filling and sealing hole so as to fill and seal the cable connecting part. Through the maintenance method, the cable connection part of the electronic gun can be accurately and efficiently maintained in a narrow space, and reliable insulation potting can be carried out.

Description

Technical Field

[0001] The present application relates to a maintenance method for an electron gun. Background Art

[0002] In radiotherapy equipment, electrons emitted by electron guns are usually accelerated by an accelerator to radiate to the patient for imaging. During this period, the filament in the electron gun often needs to be heated to more than 1000 degrees Celsius to trigger the electron emission. The electron gun is connected to a cable for power supply and signal transmission. When the electrons are triggered, the temperature of the welded cable connection can reach up to 200 degrees Celsius. Due to the start and stop operation of the electron gun and the resulting reciprocating increase and decrease of its own temperature, stress is easily generated in the welding point of the cable connection. Long-term stress can cause the connection of the cable welding to loosen and cause poor contact.

[0003] When poor contact occurs, the entire accelerator usually needs to be removed and returned to the factory for repair, which is very time-consuming and costly.

[0004] If you want to repair it on site, there are the following limitations: Since radiotherapy equipment usually generates a strong magnetic field during treatment, the accelerator is usually wrapped and covered by a magnetic field shielding plate, which results in a small on-site space available for maintenance operations; it is difficult to effectively insulate and seal the cables when reconnecting them on site.

[0005] CN216120200U, CN219445851U and CN203339105U describe technical solutions related to the connection and sealing of electron guns. Summary of the invention

[0006] Based on this, it is necessary to provide a maintenance method for an electron gun for the above-mentioned problem. The electron gun includes a cable connecting portion. The maintenance method includes: Remove the cable in the cable connection part from the electron gun; reconnecting the cable to the electron gun; Installing a potting mold around the cable connection portion; Sealing the potting mold around the cable connection portion with a sealant while leaving an open potting hole on an upper side of the potting mold; and The cable connection portion is potted by pouring potting liquid into the potting mold through the potting hole.

[0007] In one embodiment, before removing the cable in the cable connecting portion from the electron gun, the maintenance method further comprises: removing old potting compound around the cable connection portion to expose the cable connection portion; and Clean the ceramic surface and the area around the cable connections.

[0008] In one embodiment, reconnecting the cable to the electron gun comprises: Cleaning the welding hole of the cable connection part on the electron gun; removing the broken potting glue on the surface of the electron gun; and The cable of the cable connecting portion is re-welded into the welding hole.

[0009] In one of the embodiments, before re-welding the cable of the cable connecting portion into the welding hole, the maintenance method further comprises: repairing any cable with damaged insulation layer.

[0010] In one embodiment, after the cable of the cable connecting portion is re-welded into the welding hole, the repair method further comprises: If the resistance between the cathode cable and the filament cable in the cable exceeds a preset value when the cable connected thereto is shaken, the cable is welded again.

[0011] In one embodiment, the preset value is 1Ω.

[0012] In one embodiment, sealing the potting mold around the cable connection portion with a sealant comprises: sealing a gap between an edge of the potting mold and a surface against which the potting mold abuts; and The gap between the cable and the edge of the cable hole through which the cable passes is sealed.

[0013] In one of the embodiments, before pouring the potting liquid into the potting mold through the potting hole to pot the cable connection portion, the maintenance method further includes: preparing the degassed potting liquid on site.

[0014] In one embodiment, the on-site preparation of the degassed potting fluid comprises: Place silicone liquid in a vacuum bottle; connecting the vacuum bottle to a vacuum pump; and The vacuum pump is used to degas the silicone liquid to obtain the potting liquid.

[0015] In one embodiment, degassing the silicone liquid by using the vacuum pump to obtain the potting liquid includes: evacuating the vacuum bottle with the vacuum pump until bubbles rise to the top of the vacuum bottle; and The sealing element on the vacuum bottle was opened to release the gas.

[0016] In one of the embodiments, pouring the potting liquid into the potting mold through the potting hole to pot the cable connecting part includes: pouring the potting liquid into the potting mold through the potting hole; and curing the potting liquid to form a potting glue.

[0017] In one embodiment, curing the potting liquid to form potting glue includes: starting the electron gun to heat to accelerate curing.

[0018] In one embodiment, after pouring the potting liquid into the potting mold through the potting hole to pot the cable connection portion, the maintenance method further includes: The potting mold and excess potting glue around the cable connecting portion are removed.

[0019] In one embodiment, removing the potting mold and excess potting glue around the cable connecting portion comprises: cutting the potting mold along a cutting line, The potting mold is a cylindrical cup having a curved side surface and a circular base surface, and The cutting line includes an edge of the circular base surface; and a straight line on the curved side surface located on the upper side of the encapsulation mold and perpendicular to the circular base surface.

[0020] In one of the embodiments, the electron gun is connected to an accelerator of a radiotherapy apparatus.

[0021] The electron gun maintenance method can accurately and efficiently perform reliable insulation potting on the cable connection part of the electron gun in a narrow space by potting the reconnected electron gun connection part with a potting mold. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Specific embodiments are described below by way of example only and with reference to the accompanying drawings, in which: Figure 1 A schematic diagram of a field environment for implementing the electron gun maintenance method of the present application in one embodiment; Figure 2 is a schematic top view of an electron gun in one embodiment; Figure 3 is a schematic diagram of a case where a cable in a cable connecting portion is removed from an electron gun in one embodiment; Figure 4 is a schematic diagram of an embodiment in which a potting mold is installed around the cable connecting portion; Figure 5 A schematic diagram of the structure of a potting mold in an embodiment; Figure 6 It is a structural schematic diagram of a potting mold in another embodiment; Figure 7 is a schematic flow chart of a maintenance method for an electron gun in one embodiment; and Figure 8 The figure is a schematic diagram of the process of preparing the potting liquid on site in one embodiment.

[0023] Reference numerals: 1, cable; 2, potting compound; 3, shielding plate; 4, accelerator; 5, potting mold; 51, side surface; 52, base surface; 53, cable hole; 54, potting hole; 55, straight line; 56, opening; 57, slot; 6, electron gun; 61, welding hole; 7, seal; G, grid; K, cathode; F, filament. DETAILED DESCRIPTION

[0024] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0025] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0026] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0027] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0028] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0029] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0030] Figure 1 The schematic diagram of the on-site environment for implementing the electron gun maintenance method of the present application in one embodiment is shown. As shown in the figure, the connection between the cable 1 and the electron gun is potted in the potting glue 2. Figure 1 It is not visible in the figure, a part of the electron gun is located in the device to which it is attached (for example, the electron accelerator 4 of the radiotherapy device) and is connected to the attached device, and the other part is potted in the potting compound 2 together with the connection part between the cable 1 and the electron gun.

[0031] like Figure 1 As shown, the space around the part to be potted is small and surrounded by the shielding plate 3. Once the connection between the cable 1 and the electron gun in the potting glue 2 is loose, resulting in unstable connection, the entire device will fail. At this time, it is necessary to repair it, re-weld the connection between the cable 1 and the electron gun, and perform insulation potting on the connection.

[0032] The present application provides a method for repairing a cable connection portion of an electron gun of a radiotherapy device on site. The repair method comprises: Figure 7 The following steps are shown: S100 to S500.

[0033] In step S100, the cable in the cable connection part is removed from the electron gun. Specifically, the cable can be desoldered using an electric soldering iron.

[0034] Before removing the cable 1 in the cable connection part, if the cable 1 with the original connection fault is still wrapped by the old potting glue 2, it is necessary to first remove the old potting glue 2 around the cable 1 connection part to expose the cable connection part, and it is also necessary to clean the ceramic surface and the area around the cable connection part. In some embodiments, a wallpaper knife or other tools are used to clean the colloid around the electron gun lead that needs to be welded. The ceramic surface and the cable connection part can be cleaned with a bamboo stick. The bamboo stick has a low hardness and can avoid damaging the ceramic surface and the electron gun connection while cleaning the ceramic surface and the electron gun connection. Of course, the user can also use other materials to process the ceramic surface and the electron gun connection, such as plastic sticks, etc., which are not limited here.

[0035] Figure 2 , a schematic top view of an electron gun in one embodiment is shown. As shown in the figure, a grid (G), a cathode (K) and a filament (F) are arranged in sequence from the accelerator side to the outside. A welding hole 61 is arranged on the outer surface of the electron gun 6 away from the accelerator side. The welding hole 61 is used to connect with the cable 1 to form a cable connection portion. The cable connection portion described herein refers to the welding hole and the components around the welding hole for connecting the cable 1 and the electron gun. For example, when the two are connected, the cable connection portion may include the portion of the cable 1 itself close to the welding hole, the welding hole 61 on the electron gun 6, and the material for welding the two together (for example, the welding material that melts and solidifies during welding to connect the connector and the welding hole 61 together).

[0036] Figure 3 FIG. 2 is a schematic diagram showing a cable in a cable connection portion after being removed from an electron gun in an embodiment of the present application. As shown in the figure, the old potting glue 2 is cut open, exposing the electron gun 6 and the welding hole 61 of the electron gun 6, and the cable 1 has been removed from the welding hole 61.

[0037] Since the potting compound is very easy to age during the frequent heating and cooling process of the electron gun, the aged potting compound will become brittle and fragile. Therefore, it is necessary to clean the ceramic surface at the tail of the electron gun and the area around the cable connection to prevent the subsequent potting and welding from mixing with foreign matter, thereby affecting the structural strength and insulation properties of the potting compound, or affecting the stability and conductivity of the welding.

[0038] In step S200, the cable is reconnected to the electron gun.

[0039] In some embodiments, step S200 may include: cleaning the welding hole 61 of the cable connection part on the electron gun 6; removing the broken potting glue on the surface of the electron gun 6; and re-welding the cable 1 of the cable connection part to the welding hole 61. The welding hole 61 is a structure provided on the electron gun 6 for inserting the conductive part of the cable 1 to connect with the cable 1. Exemplarily, in the process of cleaning the welding hole 61 and removing the potting glue, a blowing balloon and a clean cloth may be used to clean the broken glue on the surface of the electron gun 6, and a solder sucker, a paper clip, and a thin steel wire may be used to clean the welding hole 61 to clean the welding slag, broken glue and other impurities in the welding hole 61. Prevent the mixing of foreign matter into the potting glue and welding during subsequent potting and welding, thereby affecting the structural strength and insulation properties of the potting glue, or affecting the stability and conductivity of the welding.

[0040] In one embodiment of the present application, when reconnecting the cable to the electron gun, it is necessary to check whether the cable is damaged. If the insulating sheath of the cable is damaged, use wire strippers to remake the cable and repair the insulating sheath of the cable. Since the accelerator operates at high temperature for a long time, the cable is prone to aging in this environment, and the cable is easily damaged when the original potting glue 2 is removed. Optionally, a new cable can be used to replace the aged old cable. Thus, before re-welding and potting, the reliability and stability of the cable itself are guaranteed to prevent problems with the cable itself after re-welding and potting, and maintenance is required again. Cables with good insulation layers are conducive to the stable operation of the electron gun and the safety of the equipment.

[0041] In one embodiment of the present application, when the cable is re-soldered into the welding hole, lead-free solder and a soldering iron are used to first tin the surface of the cable, then fill the solder into the welding hole, and finally insert the cable into the welding hole, thereby the cable is welded in the welding hole.

[0042] In one embodiment of the present application, after the cable of the cable connection part is re-welded into the welding hole 61, a multimeter is used to check the resistance between the cable of the cathode K and the cable of the filament F, which is usually between 0.4Ω and 0.7Ω. When detecting the resistance, shake the cable at the welding point by hand. If the resistance value changes, and the changed resistance value is greater than 1Ω, or the changed resistance value is greater than 0.7Ω, or the resistance value keeps changing, it is necessary to check the welding quality and re-weld the wire if necessary. In this way, the welding quality can be preliminarily detected to prevent the welding quality problem from being discovered when the equipment is used after potting. At this time, the potting needs to be removed and re-welded, which causes trouble for the maintenance personnel and wastes time.

[0043] After welding is completed, the welded joints must be potted.

[0044] In step S300, a potting mold is installed around the cable connecting portion.

[0045] Figure 4 2 shows a schematic diagram of an embodiment in which a potting mold 5 is installed around the cable connection portion. As shown in the figure, the potting mold 5 is installed around the cable connection portion of the electron gun 6, and the potting mold 5 is properly sealed around the cable connection portion with a seal 7.

[0046] Figure 5 The schematic diagram of the structure of the potting mold 5 used in one embodiment of the present application is shown. In some embodiments of the present application, the potting mold 5 is made of a transparent material.

[0047] As shown in the figure, the potting mold 5 is a cylindrical cup-shaped object with a curved side surface 51 and a circular base surface 52 and an opening 56. A potting hole 54 is formed on the side surface 51 at a position close to the base surface 52, and a cable hole 53 is formed on the side surface 51 at a position away from the base surface 52. When installing the potting mold 5, the mold cover is placed on the connection between the electron gun 6 and the cable, so that the opening 56 of the potting mold 5 abuts against the wall of the accelerator 4 next to the electron gun 6, the base surface 52 is opposite to the cable connection part, and the base surface 52 and the cable connection part are at a certain distance. At this time, the connection between the electron gun 6 and the cable is located in the middle of the inner cavity of the potting mold 5, and the cable passes through the cable hole 53 of the potting mold 5. The potting hole 54 is set at a position close to the base surface 52 on the side surface 51, and the space between the base surface 52 and the cable connection part is relatively ample, which is conducive to injecting the potting liquid into the potting mold 5 and can reduce the risk of residual bubbles in the potting glue. If the potting hole 54 is arranged on a side close to the opening 56 of the potting mold 5, the space is very narrow due to the obstruction of the shielding plate 3 next to the accelerator 4, which is very unfavorable for the operation of injecting the potting liquid into the potting mold 5. Of course, the position of the potting hole 54 can be set according to the needs of the user and is not limited here.

[0048] Optionally, the potting mold 5 is cylindrical, and the cable connection part is also cylindrical. The potting mold 5 can be coaxially arranged with the cable connection part, and a preset gap is provided between the side surface 51 of the potting mold 5 and the outer peripheral surface of the cable connection part. The potting glue fills the preset gap and wraps the cable connection part therein, thereby playing the role of insulating and sealing. Of course, the potting mold and the cable connection part can also adopt other shapes, which are not limited here.

[0049] Figure 6The schematic diagram of the structure of the potting mold used in another embodiment of the present application is shown. The potting hole 54 is still formed on the side surface 51 at a position close to the base surface 52, but the cable hole 53 is formed on the side surface 51 at a certain distance from the opening 56. When the potting mold 5 is installed around the connecting part, the cable needs to be moved to the cable hole 53 through the slot 57 and passed out from the cable hole 53. In this embodiment, the potting mold 5 is made of an elastic deformable material, and the operator can apply a certain force on both sides of the slot 57 to expand the width of the slot 57 for the cable to pass through.

[0050] In some embodiments of the present application, the three cables 1 of the electron gun may be bundled together with a strapping tape, and then pollutants on the surface of the electron gun 6 may be cleaned with a blowing balloon and a cloth, and then the potting mold 5 may be installed around the cable connection portion.

[0051] In step S400 , a sealing member is used to seal the potting mold around the cable connection portion, while leaving an open potting hole on the upper side of the potting mold.

[0052] The potting mold 5 is sealed with a sealant 7 around the cable connection part, and an open potting hole 54 is left on the upper side of the potting mold 5, so that the space formed in the potting mold 5 is connected to the outside only through the inlet and outlet of the potting hole 54. When the potting liquid is subsequently poured into the potting mold 5 through the potting hole 54, the potting liquid will not leak from other holes or gaps, thereby avoiding poor potting effect, failure to completely pot the cable connection part in the potting glue 2, or potting liquid flowing into other parts of the equipment to cause malfunctions.

[0053] In some embodiments of the present application, the sealant 7 is sealing mud and / or hot melt adhesive. In some embodiments of the present application, the sealing mud is used to seal the gap between the edge of the potting mold 5 and the surface abutting the potting mold 5 (i.e., the outer surface of the electron accelerator 4); and the sealing mud is used to seal the gap between the edge of the cable hole 53 through which the cable 1 passes and the cable 1. If the potting mold 5 is made of plastic and is not integrally formed, there are gaps between the components (e.g. Figure 6 If there are cracks on the surface of the mold, or the slots 57 of the potting mold shown in the figure, then a hot melt glue gun can be used to seal these gaps and cracks. Hot melt glue is usually used to seal between plastics, and sealing mud is usually used to seal between plastic molds and copper metal. Of course, users can also choose the material of the seal according to their needs, which is not limited here.

[0054] In step S500, a potting liquid is poured into the potting mold through the potting hole to pot the cable connecting portion.

[0055] When using the mold for potting, after placing the part to be potted (i.e., the connection between the cable 1 and the electron gun 6) in the relatively middle position of the potting mold 5 and properly sealing the potting mold 5, pour the potting liquid into the potting mold 5. By sealing the potting mold 5, the connection to be repaired can be accurately defined by the potting mold 5 in the narrow space of on-site maintenance, and the connection can be ensured to be potted by potting the entire inside of the potting mold 5; when injecting the potting liquid into the potting mold 5, since the potting mold 5 defines the potting area and the potting mold 5 is properly sealed, the potting liquid will not accidentally flow to other components of the equipment or other devices on site, causing unnecessary trouble.

[0056] In some embodiments, before step S500, the on-site maintenance method of the cable connection part of the electron gun provided by the present application further includes: Figure 8 The process of preparing the degassed potting liquid on site is shown. By preparing the degassed potting liquid on site, the strength, sealing and insulation properties of the potting liquid can be guaranteed to the greatest extent possible. The on-site preparation described in this article refers to preparation at the maintenance site or the local maintenance site, without disassembling the equipment to be repaired and transporting it back to the factory or a special maintenance site for preparation there.

[0057] like Figure 8 As shown, the process of preparing the degassed potting liquid on site includes: S501 placing silicone liquid in a vacuum bottle; S502 connecting the vacuum bottle to a vacuum pump; and S503 using a vacuum pump to degas the silicone liquid to obtain the potting liquid. After the potting liquid is prepared, the potting liquid is poured into the potting mold 5 and solidified to form the potting glue 2.

[0058] The potting liquid needs to be prepared on site. If it is prepared in advance, the properties of the potting liquid may change in advance during storage and transportation, such as premature solidification or mixing with a large amount of other impurities or gases. The structural strength and insulation properties of the potting glue formed after the potting liquid with changed properties solidifies cannot be guaranteed. Using a vacuum bottle and a vacuum pump to prepare the potting liquid on site with silicone liquid can maximize the performance of the potting liquid. After removing the gas in the silicone liquid on site, the potting effect is better, and the potting glue formed after potting is more stable, firm, reliable, and has better insulation properties.

[0059] In one embodiment of the present application, two silicone products A and B are first prepared, 200g of silicone A and 20g of silicone B are poured into a beaker, and then stirred evenly with a stirring rod. The stirred mixed silicone liquid is then placed into a vacuum bottle together with the beaker. Cover the vacuum bottle and connect the vacuum bottle to a vacuum pump. Start the vacuum pump and start pumping air, and stop pumping air when the bubbles rise to the bottle mouth. Then lift the leather pad on the vacuum bottle and press the vent to deflate, and repeat this process until no bubbles are seen within 1 minute of pumping air. The total time for the deflation process lasts about 1.5 hours. The vacuum pump needs to be started frequently for deflation in the first half hour, and only deflation is required every 10 minutes in the next hour.

[0060] After the air is released, the prepared potting liquid can be poured into the installed and properly sealed potting mold 5 through the potting hole 54. After it is filled, wait for the potting liquid to solidify into the potting glue 2. During the curing process, the curing time can also be shortened by heating with an electron gun. For example, the electron gun 6 is controlled to enter a preheating state, or a standby voltage is applied to the electron gun 6 to indirectly heat the potting liquid by heating the electron gun 6. While the electron gun is heating, it can also test whether the cable connection is intact and stable, that is, whether the current and electrical signals can be stably input and output. In this way, while shortening the curing time, stability testing is performed to improve efficiency.

[0061] When using this method to repair the cable connection of the electron gun of a radiotherapy device in the field, a special repair tool kit can be used. The repair tool kit contains the potting mold and all other tools that may be used as described above.

[0062] In one embodiment of the present application, after pouring the potting liquid into the potting mold through the potting hole to pot the cable connection part, the potting mold and excess potting glue around the cable connection part are removed. By removing the potting mold and excess potting glue, the size of the potting part can be made smaller, the structure of the equipment can be made more compact, and unnecessary collisions during the operation of the equipment can be prevented, thereby affecting the potting performance and connection stability. Due to the more compact structure, a cover plate or a blocking member can also be installed around or above the potting part for protection.

[0063] In one embodiment of the present application, when removing the potting mold, the potting mold can be cut along a specific cutting line, and the specific cutting line includes the edge of the circular base surface 52. The circular base surface 52 can be removed after cutting along the edge of the circular base surface 52. The specific cutting line can also include a straight line 55 on the curved side surface 51 located on the upper side of the potting mold and perpendicular to the circular base surface 52, and the side surface 51 can be removed after cutting along the straight line 55. After the potting mold is cut in this embodiment, the potting mold is removed, and there is no need to squeeze and pull the solidified potting glue 2, so as to avoid the process of removing the potting mold causing the potting glue 2 to be subjected to greater stress, thereby affecting the potting performance and connection stability.

[0064] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0065] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0066] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A maintenance method for an electron gun, the electron gun comprising a cable connection portion, characterized in that: The maintenance method comprises: Remove the cable in the cable connection part from the electron gun; reconnecting the cable to the electron gun; Installing a potting mold around the cable connection portion; Sealing the potting mold around the cable connection portion with a sealant while leaving an open potting hole on an upper side of the potting mold; and The cable connection portion is potted by pouring potting liquid into the potting mold through the potting hole.

2. The maintenance method according to claim 1, characterized in that: Before removing the cable in the cable connecting portion from the electron gun, the maintenance method further comprises: removing old potting compound around the cable connection portion to expose the cable connection portion; and Clean the ceramic surface and the area around the cable connections.

3. The maintenance method according to claim 1, characterized in that: The reconnecting the cable to the electron gun comprises: Cleaning the welding hole of the cable connection part on the electron gun; removing the broken potting glue on the surface of the electron gun; and The cable of the cable connecting portion is re-welded into the welding hole.

4. The maintenance method according to claim 3, characterized in that: Before re-welding the cable of the cable connecting portion into the welding hole, the maintenance method further comprises: repairing any cable with damaged insulation layer.

5. The maintenance method according to claim 3, characterized in that: After re-welding the cable of the cable connecting portion into the welding hole, the repair method further comprises: If the resistance between the cathode cable and the filament cable in the cable exceeds a preset value when the cable connected to the cable is shaken, the cable is welded again.

6. The maintenance method according to claim 5, characterized in that: The preset value is 1Ω.

7. The maintenance method according to claim 1, characterized in that: The step of sealing the potting mold around the cable connection portion with a sealant comprises: sealing a gap between an edge of the potting mold and a surface against which the potting mold abuts; and The gap between the cable and the edge of the cable hole through which the cable passes is sealed.

8. The maintenance method according to claim 1, characterized in that: Before pouring the potting liquid into the potting mold through the potting hole to pot the cable connection portion, the maintenance method further includes: preparing the degassed potting liquid on site.

9. The maintenance method according to claim 8, characterized in that: The on-site preparation of the degassed potting liquid comprises: Place silicone liquid in a vacuum bottle; connecting the vacuum bottle to a vacuum pump; and The vacuum pump is used to degas the silicone liquid to obtain the potting liquid.

10. The maintenance method according to claim 9, characterized in that: The step of degassing the silicone liquid by using the vacuum pump to obtain the potting liquid comprises: evacuating the vacuum bottle with the vacuum pump until bubbles rise to the top of the vacuum bottle; and The sealing element on the vacuum bottle was opened to release the gas.

11. The maintenance method according to claim 1, characterized in that: The step of pouring the potting liquid into the potting mold through the potting hole to pot the cable connection part comprises: pouring the potting liquid into the potting mold through the potting hole; and curing the potting liquid to form a potting glue. The step of curing the potting liquid to form a potting glue comprises: starting the electron gun to heat the potting liquid to accelerate the curing.

12. The maintenance method according to claim 1, characterized in that: After pouring the potting liquid into the potting mold through the potting hole to pot the cable connection part, the maintenance method further includes: The potting mold and excess potting glue around the cable connecting portion are removed.

13. The maintenance method according to claim 12, characterized in that: The removing of the potting mold and the excess potting glue around the cable connection part comprises: cutting the potting mold along a cutting line, The potting mold is a cylindrical cup having a curved side surface and a circular base surface, and The cutting line includes an edge of the circular base surface; and a straight line on the curved side surface located on the upper side of the encapsulation mold and perpendicular to the circular base surface.

14. The maintenance method according to claim 1, characterized in that: The electron gun is connected to an accelerator of a radiotherapy apparatus.

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