Synchrotron injection lines, ion accelerator vacuum systems and their construction methods

Abstract

This invention relates to the field of accelerator technology, and discloses a synchrotron accelerator injection line, an ion accelerator vacuum system, and a method for its construction. The first assembly unit of the injection line is equipped with a first sputtering ion pump, the second assembly unit is equipped with a second sputtering ion pump whose ultimate vacuum performance is superior to that of the first sputtering ion pump, and the third assembly unit is equipped with ultimate vacuum performance all superior to 1.0 × 10⁻⁶. ‑9 The third sputtering ion pump and NEG pump at Pa form a smooth pressure gradient along the beamline. The NEG pump enhances the ability to obtain and maintain extremely high vacuum at the end. This system, in conjunction with the first roughing pump unit for initial evacuation and the valve assembly for section isolation, works synergistically to achieve high vacuum from 10 Pa within a limited physical space. ‑6 Pa to 10 ‑10 Pa maintains a stable vacuum transition across four orders of magnitude and ensures that each section can be independently inspected and processed, thereby maintaining the extremely high vacuum environment required by the synchrotron.

Description

Technical Field

[0001] This invention relates to the field of accelerator technology, and in particular to a synchrotron injection line, an ion accelerator vacuum system, and a method for its construction. Background Technology

[0002] The vacuum system of an ion accelerator mainly consists of several subsystems, including a linear injector, a synchrotron injection line, a synchrotron, and a high-energy beam transport line. This is specifically designed for accelerating ions from H... 2+ To bismuth ions 209 Bi 32+ A fully stable radionuclide beam apparatus, typically consisting of a linear injector, includes an ion source, a low-energy beam transfer line (LEBT), a radio frequency quadrupole (RFQ) acceleration structure, a medium-energy beam transfer line (MEBT), a drift tube linear injector (DTL), a high-energy beam transfer line (HEBT), and a corresponding radio frequency power source system. This component's function is to initially accelerate the beam drawn from the ion source to the energy required for synchrotron injection.

[0003] In a linear injector, the beam passes through only once, resulting in relatively small beam losses due to interaction with residual gas. Therefore, a vacuum level generally needs to be better than 5.0 × 10⁻⁶. -6 Pa. For compact devices accelerating fully stable nuclides with high beam energies, linear injectors are typically lengthened (e.g., by adding DTL segments), which reduces the available space in the synchrotron injection line. The synchrotron injection line connects the linear injector to the synchrotron, achieving phase space matching between the two.

[0004] It is worth noting that for heavy ions with relatively small mass-to-charge ratios (such as Bi), 32+ Even after acceleration by the linear injector, the injected energy remains low, resulting in a short lifetime within the synchrotron. If the residual gas density in the vacuum environment is high, the interaction between ions and gas molecules will further shorten the beam lifetime. Therefore, to ensure the survival rate of ions during cyclic acceleration, the vacuum level of the synchrotron needs to be maintained at 10⁻⁶. -10 Extremely high vacuum level of Pa.

[0005] It can be seen that, while simultaneously accelerating light ions (such as H+), 2+ ) to heavy ions (e.g., Bi) 32+ Furthermore, in compact devices that pursue high energy output, it is necessary to achieve output from the linear injector outlet (10... -6 Pa) to the synchrotron inlet (10 -10 Within an extremely limited axial distance between Pa, a vacuum transition spanning four orders of magnitude is achieved. Summary of the Invention

[0006] This invention provides a synchrotron injection line, an ion accelerator vacuum system, and a construction method, aiming to achieve a vacuum level of 10⁻⁶ within the injection line under conditions of strictly limited axial space. -6 Pa to 10 -10 Pa, vacuum stability across four orders of magnitude, reliable transition.

[0007] The synchrotron injection line provided in the first aspect of the present invention includes: The first assembly unit includes a first vacuum chamber, a first sputtering ion pump, and a first titanium sublimation pump; both the first sputtering ion pump and the first titanium sublimation pump are installed in the first vacuum chamber; the inlet of the first vacuum chamber is used to connect to the outlet of the linear injector. Multiple second assembly units, each comprising a second vacuum chamber, a second sputtering ion pump, and a second titanium sublimation pump; both the second sputtering ion pump and the second titanium sublimation pump are installed in the second vacuum chamber, and the ultimate vacuum specification of the second sputtering ion pump is better than 1.0 × 10⁻⁶. -9 Pa, the ultimate vacuum performance of the second sputtering ion pump is better than that of the first sputtering ion pump. The third assembly unit includes a third vacuum chamber, a third sputtering ion pump, and a NEG pump; both the third sputtering ion pump and the NEG pump are installed in the third vacuum chamber; the outlet of the third vacuum chamber is used to connect to the inlet of the synchrotron; the ultimate vacuum parameters of both the third sputtering ion pump and the NEG pump are better than 1.0 × 10⁻⁶. -9 Pa; The first vacuum chamber, a plurality of second vacuum chambers and the third vacuum chamber are connected in series along the beamline; The first roughing pump unit includes a first mechanical pump, a first molecular pump, and a first control valve; the first molecular pump is installed in the first vacuum chamber, and the inlet of the first molecular pump is connected to the inner cavity of the first vacuum chamber; the first mechanical pump is connected to the outlet of the first molecular pump; and the first control valve is used to open or close the inlet of the first molecular pump. The valve assembly includes a first valve and a second valve; the first valve is located at the inlet of the first vacuum chamber and is used to open or close the inlet of the first vacuum chamber; the second valve is located at the outlet of the third vacuum chamber and is used to open or close the outlet of the third vacuum chamber.

[0008] According to the synchrotron injection line provided by the present invention, the number of the first assembly units is at least two, and the two first vacuum chambers are connected in series along the beamline. The number of the second assembly units is 4, and the 4 second vacuum chambers are connected in series along the beam line.

[0009] According to the synchrotron injection line provided by the present invention, the number of second titanium sublimation pumps in the second assembly unit connected to the third vacuum chamber is greater than the number of second titanium sublimation pumps in the other second assembly units.

[0010] The synchrotron injection line provided by the present invention further includes: The fourth assembly unit includes a fourth vacuum chamber and a fourth titanium sublimation pump disposed in the fourth vacuum chamber; the fourth vacuum chamber is connected in series between two adjacent second vacuum chambers along the beam line.

[0011] The synchrotron injection line provided by the present invention further includes: The second roughing pump unit includes a second mechanical pump, a second molecular pump, and a second control valve; the second molecular pump is installed in the fourth vacuum chamber, and the inlet of the second molecular pump is connected to the inner cavity of the fourth vacuum chamber; the second mechanical pump is connected to the outlet of the second molecular pump; and the second control valve is used to open or close the inlet of the second molecular pump.

[0012] According to the synchrotron injection line provided by the present invention, the valve assembly further includes: A quick-closing valve is installed at the inlet of the first valve. When the actual vacuum level of the linear injector is lower than a preset threshold, the quick-closing valve switches from the open state to the closed state to achieve vacuum isolation.

[0013] The synchrotron injection line provided by the present invention further includes: Multiple vacuum pipes and multiple corrugated pipes are provided, and the first vacuum chamber, the second vacuum chamber, and the third vacuum chamber are connected in series through the vacuum pipes and corrugated pipes.

[0014] According to the synchrotron injection line provided by the present invention, the first vacuum chamber, the second vacuum chamber, the third vacuum chamber, the vacuum pipe and the bellows are all made of high-performance austenitic stainless steel.

[0015] A second aspect of the present invention provides a vacuum system for an ion accelerator, comprising: Linear injector; The synchrotron injection line described in any of the preceding claims, wherein the inlet of the first vacuum chamber of the synchrotron injection line is connected to the outlet of the linear injector; A synchrotron, the inlet of which is connected to the third vacuum chamber of the synchrotron injection line.

[0016] The third aspect of the present invention provides a method for constructing a synchrotron injection line, which is used to construct the synchrotron injection line described in any of the above claims, including ultra-high vacuum manufacturing, integrated installation, full-line sealing leak detection and baking treatment; The ultra-high vacuum manufacturing process includes the following steps: The vacuum components are made of high-performance austenitic stainless steel; wherein, the vacuum components include a first vacuum chamber, a second vacuum chamber, a third vacuum chamber, a fourth vacuum chamber, and vacuum pipes; the dimensional tolerance of the vacuum components is no greater than 0.5 mm, and the form and position tolerance is no greater than 0.5 mm; The vacuum component is subjected to high-temperature degassing treatment; The vacuum component after degassing is straightened to ensure that its dimensional and geometric tolerances meet the design requirements; in a vacuum cleanroom, the straightened vacuum component is assembled and welded to the corresponding flange; wherein the flange is subjected to ultrasonic cleaning and high-temperature degassing treatment; The vacuum components, after flange welding, are subjected to ultrasonic cleaning. The vacuum component is subjected to low-temperature degassing after ultrasonic cleaning; In a vacuum cleanroom, the vacuum components, after undergoing low-temperature degassing, are subjected to dimensional, geometrical, and positional tolerance, and leak rate testing. The dimensional and geometrical tolerances of the vacuum components are controlled to be no greater than 0.5 mm; the overall leak rate is tested to ensure it does not exceed 5.0 × 10⁻⁶ mm. -8 Pa·L / s; The integrated installation includes the following steps: If the inspection is passed, continue to install the baking heating jacket of the vacuum pipeline in the clean room, cover the flange ports of the vacuum pipeline and the corrugated pipe with aluminum blind plates for sealing, and fill the vacuum pipeline and the corrugated pipe with high-purity nitrogen for protective sealing. If the test is passed, continue to complete the integration and assembly of the vacuum chamber, vacuum measuring elements, beam diagnostic elements and vacuum valves in the clean room to form an assembly module; perform overall leak testing on the assembly module, and after confirming that the leak rate is qualified, cover the remaining flange ports of the assembly module with aluminum blind plates for sealing, and fill it with high-purity nitrogen for protection. The sealed assembly module is aligned at the installation site to ensure that the coaxiality error between the beam line center axis and the flange center axis in the beam line direction is no more than 0.5 mm. Finally, the flanges of adjacent components such as the vacuum pipe, the bellows, and the assembly module are connected. All flange connection processes are carried out in a closed mobile cleanroom.

[0017] The synchrotron injection line provided by this invention constructs a gradient pumping system through a series arrangement of multi-stage combined units. The first combined unit is equipped with a first sputtering ion pump, the second combined unit is equipped with a second sputtering ion pump whose ultimate vacuum performance is superior to that of the first sputtering ion pump, and the third combined unit is equipped with ultimate vacuum performance superior to 1.0 × 10⁻⁶. -9 The third sputtering ion pump and NEG pump of Pa form a smooth pressure gradient along the beamline. Furthermore, the third combined unit utilizes the NEG pump at the end to enhance the acquisition and maintenance of extremely high vacuum. This system, in conjunction with the first roughing pump unit for initial evacuation and the valve assembly for section isolation, works synergistically to achieve high vacuum from 10... -6 Pa to 10 - 10 The Pa system provides a stable vacuum transition spanning four orders of magnitude and ensures that each section can be independently inspected and processed, thereby effectively maintaining the extremely high vacuum environment required by the synchrotron and ensuring the stability of beam transmission.

[0018] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention and are not considered as limitations on this application. Moreover, those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0020] Figure 1 This is a three-dimensional structural diagram of the synchrotron injection line provided by the present invention.

[0021] Figure 2 This is a top view of the synchrotron injection line provided by the present invention.

[0022] Figure 3 This is a schematic diagram of the structure of the ion accelerator vacuum system provided by the present invention.

[0023] Figure 4 This is a flowchart illustrating the method for constructing a synchrotron injection line provided by the present invention.

[0024] Figure label: 100. Synchrotron injection line; 200. Linear injector; 300. Synchrotron; 110. First assembly unit; 111. First vacuum chamber; 112. First sputtering ion pump; 113. First titanium sublimation pump; 120. Second assembly unit; 121. Second vacuum chamber; 122. Second sputtering ion pump; 123. Second titanium sublimation pump; 130. Third assembly unit; 131. Third vacuum chamber; 132. Third sputtering ion pump; 133. NEG pump; 140. First roughing unit; 141. First molecular pump; 142. First control valve; 150. Valve assembly; 151. First valve; 152. Second valve; 153. Quick-closing valve; 160. Fourth assembly unit; 161. Fourth vacuum chamber; 162. Fourth titanium sublimation pump; 170. Second roughing unit; 171. Second molecular pump; 172. Second control valve; 181. Vacuum pipe; 182. Corrugated pipe; 190. Vacuum gauge. Detailed Implementation

[0025] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0026] The specific terms used in this specification are for illustrative purposes only and are not intended to limit the illustrated embodiments. For example, expressions such as "same" and "identical" not only indicate a strictly identical state, but also indicate a state with tolerances or differences in the degree of functionality. For example, expressions indicating relative or absolute arrangement such as "in a certain direction," "along a certain direction," "side by side," "perpendicular," "centered on," "concentric," or "coaxial" not only strictly indicate such an arrangement, but also indicate a state of relative displacement by tolerances or angles or distances with the same degree of functionality.

[0027] The terms “center,” “longitudinal,” “lateral,” “length,” “width,” “thickness,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” “outer,” “clockwise,” “counterclockwise,” “axial,” “radial,” and “circumferential” indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0028] Furthermore, features specified as "first" or "second" may explicitly or implicitly include one or more of those features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly specified. In the description of the embodiments of this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, B1 and / or B2 can represent: B1 existing alone, B1 and B2 existing simultaneously, and B2 existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0029] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0030] The following is combined Figure 1 and Figure 2 The structure and operation of the synchrotron injection line provided by this invention are described.

[0031] like Figure 1 and Figure 2 As shown, a specific embodiment of the first aspect of the present invention provides a synchrotron injection line 100, which includes a first assembly unit 110, a plurality of second assembly units 120, a third assembly unit 130, a first roughing pump unit 140, and a valve group 150.

[0032] The first assembly unit 110 includes a first vacuum chamber 111, a first sputtering ion pump 112, and a first titanium sublimation pump 113; the first sputtering ion pump 112 and the first titanium sublimation pump 113 are both installed in the first vacuum chamber 111; the inlet of the first vacuum chamber 111 is used to connect to the outlet of the linear injector 200 as the starting section of vacuum transition.

[0033] The second assembly unit 120 includes a second vacuum chamber 121, a second sputtering ion pump 122, and a second titanium sublimation pump 123. Both the second sputtering ion pump 122 and the second titanium sublimation pump 123 are installed in the second vacuum chamber 121. The inlet of the second vacuum chamber 121 is connected to the outlet of the first vacuum chamber 111. The ultimate vacuum of the second sputtering ion pump 122 is better than 1.0 × 10⁻⁶. -9The ultimate vacuum performance of the second sputtering ion pump 122 is superior to that of the first sputtering ion pump 112. Preferably, the ultimate vacuum performance of the first sputtering ion pump 112 is superior to 1.0 × 10⁻⁶ Pa. -8 Pa. By making the ultimate vacuum index of the second sputtering ion pump 122 better than that of the first sputtering ion pump 112, and by arranging multiple second assembly units 120 in series along the beam line, a gradient pumping layout is formed, which helps to form a smooth pressure step along the length of the injection line and achieve a gradual transition of vacuum.

[0034] The third assembly unit 130 includes a third vacuum chamber 131, a third sputtering ion pump 132, and a NEG pump 133; both the third sputtering ion pump 132 and the NEG pump 133 are installed in the third vacuum chamber 131; the outlet of the third vacuum chamber 131 is connected to the inlet of the synchrotron 300, and the ultimate vacuum performance of the third sputtering ion pump 132 and the NEG pump 133 is better than 1.0 × 10⁻⁶. -9 Pa. That is, a third assembly unit 130 is set at the end of the injection line. The NEG pump 133 is set up to enhance the ability to obtain and maintain the ultra-high vacuum at the end by utilizing its high pumping speed characteristics for active gases, so as to meet the docking requirements with the ultra-high vacuum environment of the synchrotron 300. The first vacuum chamber 111, multiple second vacuum chambers 121 and the third vacuum chamber 131 are arranged in series along the beamline.

[0035] The first roughing pump unit 140 includes a first mechanical pump, a first molecular pump 141, and a first control valve 142. The first molecular pump 141 is installed in the first vacuum chamber 111, and its inlet is connected to the inner cavity of the first vacuum chamber 111. The first mechanical pump is connected to the outlet of the first molecular pump 141. The first roughing pump unit 140 is used to pre-pump the injection line from atmospheric pressure to the pressure range that the high vacuum pump can start when the system is started. The first control valve 142 is used to open or close the inlet of the first molecular pump 141. When the first control valve 142 switches from the open state to the closed state, it can isolate the first roughing pump unit 140 from the main vacuum system of the injection line to prevent gas backflow from deteriorating the ultra-high vacuum environment.

[0036] Valve assembly 150 includes a first valve 151 and a second valve 152. The first valve 151 is located at the inlet of the first vacuum chamber 111 and is used to open or close the inlet of the first vacuum chamber 111. The second valve 152 is located at the outlet of the third vacuum chamber 131 and is used to open or close the outlet of the third vacuum chamber 131. By opening or closing the first valve 151 and the second valve 152, the synchrotron injection line 100 can be isolated as an independent vacuum section from the linear injector 200 and the synchrotron 300, which facilitates independent vacuuming, leak detection and baking treatment without affecting adjacent systems.

[0037] The process of using the synchrotron injection line in this embodiment includes: System isolation and rough evacuation: First, both valves 151 and 152 are switched to the closed state to achieve vacuum isolation between the synchrotron injection line and the linear injector 200 and synchrotron 300. Then, the first mechanical pump (not shown in the figure) of the first rough evacuation unit 140 is started for pre-evacuation. When the system vacuum level is better than 200 Pa, the first molecular pump 141 is started for further evacuation until the vacuum level is better than 10 Pa. -4 The Pa level creates conditions for leak detection of the entire line.

[0038] Leak testing and baking: After confirming the system's sealing performance, the synchrotron injection line is baked to further reduce the surface gas escaping rate of each vacuum chamber wall and component. The baking process includes heating, holding, and cooling stages. During the holding stage, each sputtering ion pump is started sequentially to degas the titanium filaments of each titanium sublimation pump and to activate NEG pump 133, fully restoring and enhancing its pumping performance. After the holding stage, the system begins programmed cooling. Each sputtering ion pump and NEG pump 133 cools synchronously with the heating system. When the temperature drops to the preset value, the degassing operation of the titanium sublimation pump is stopped, and it is switched to sublimation mode, forming a fresh film on the pump body surface to enhance pumping capacity. After the sublimation process is completed, the first control valve 142 and the first molecular pump 141 are closed, and the first rough pump unit 140 is isolated from the main vacuum system. The ultra-high vacuum state of the system is maintained by each sputtering ion pump, each titanium sublimation pump and NEG pump 133.

[0039] Performance Verification and Conclusion: After baking and cooling the system to room temperature, the vacuum level at the test point near the synchrotron injection line outlet reached 10. -10 The Pa level. At this point, the average vacuum of the linear injector is 10. -6 The Pa level, and the average vacuum of the synchrotron 300 are 10. -10 The Pa level indicates that the vacuum level in each region has reached the preset target value.

[0040] To finally verify the vacuum transition performance of the injection line, the first valve 151 and the second valve 152 were opened, fully connecting the synchrotron injection line 100 with the linear injector 200 and the synchrotron 300. After connection, the data showed that the vacuum level at the measurement point of the synchrotron injection line 100 remained at 10. -10 The average vacuum level of the linear injector 200 remains at the Pa level, still in the range of 10 Pa. -6 The Pa level is still around 10, while the average vacuum level of the synchrotron 300 remains at 10. -10 Pa level.

[0041] Experimental results clearly show that after the first valve 151 and the second valve 152 are opened, the extremely high vacuum environment (10) of the synchrotron 300 is maintained. -10 (Pa level) was not affected by the high vacuum environment at the 200 outlet of the linear injector (10) -6 Despite the significant impact of the Pa level (on the order of Pa), the vacuum level remained stable. This demonstrates that the design and manufacturing process of the synchrotron injection line 100 in this embodiment successfully achieved vacuum from the inlet end 10 within a limited length of approximately 20 meters. -6 Pa to the outlet end 10 -10 The system smoothly transitions across a wide range of vacuum gradients spanning four orders of magnitude, with stable transitions and fluctuations within permissible limits, effectively ensuring the stability of the synchrotron's 300 vacuum environment and the reliable operation of the entire system.

[0042] It should be noted that the full name of the NEG pump is the Nonevaporable Getter pump, also known as a non-evaporable getter pump.

[0043] In some embodiments, the baking process sequentially includes a heating stage, a heat preservation stage, and a cooling stage, each stage being fully automatically controlled by the baking control system, specifically including the following steps: 1. Heating Phase Set the baking temperature to T1 and the heating rate to V1. Optionally, T1 can be set to 200-300 degrees Celsius (°C); V1 can be set to 0.3-0.7 degrees Celsius per minute (°C / min).

[0044] After the heating phase begins, the baking of each sputtering ion pump is started simultaneously.

[0045] After the heating process lasts for approximately time t1, the system temperature reaches T1, and then enters the heat preservation stage. Optionally, the value of t1 can range from 7 to 8 hours (h). 2. Insulation Stage: The insulation temperature is T1, and the insulation time is t2. Optionally, t2 can be set between 40 and 50 degrees Celsius, in hours (h).

[0046] After entering the heat preservation stage (t3 time), turn on the power supply of each sputtering ion pump and confirm that the power supply of each sputtering ion pump is working properly. Optionally, the value of t3 can be 8~12 hours (h).

[0047] Within 1 to 5 hours after the sputtering ion pump power supply is started normally, turn on the power supply of each titanium sublimation pump to degas the titanium wire of the titanium sublimation pump.

[0048] After the titanium sublimation pump power supply has been running for a period of time, turn on the ultra-high vacuum gauge. This ultra-high vacuum gauge is installed near the synchrotron 300 on the injection line and is used to detect the actual vacuum level of the injection line.

[0049] Before the end of the heat preservation stage, turn on the heating power of NEG pump 133 and heat the getter from room temperature to 500℃~600℃ at a heating rate of 10℃ / min~15℃ / min, and keep it at 500℃~600℃ for 0.5 h~1.5 h to complete the activation treatment of NEG pump 133.

[0050] During the heat preservation stage, ensure that the baking control system, sputtering ion pump power supply, titanium sublimation pump power supply, NEG pump 133 power supply, and ultra-high vacuum gauge are all in normal operating condition.

[0051] 3. Cooling stage After the heat preservation phase, the system cools down at a rate of V2; simultaneously, the heating power supplies of the sputtering ion pump and NEG pump 133 are disconnected, and the sputtering ion pump and NEG pump 133 cool down synchronously. Optionally, the value of V2 ranges from 0.3 to 0.7, with units of degrees Celsius per minute (°C / min).

[0052] When the system temperature drops to 170℃~190℃, stop the degassing operation of all titanium sublimation pumps and switch them to sublimation mode.

[0053] After sublimation is completed, the first control valve 142 and the first molecular pump 141 are closed to isolate the first vacuum chamber 111 from the first roughing pump unit 140.

[0054] When the baking temperature drops below 60℃, the baking control system is turned off, and the cooling process ends.

[0055] After the system temperature drops to room temperature and remains at that temperature for a preset time, the titanium sublimation pump can be sublimated again to enhance its pumping performance.

[0056] For example, in some embodiments, the baking process sequentially includes a heating stage, a holding stage, and a cooling stage, each stage being fully automatically controlled by the baking control system, specifically including the following steps: 1. Heating Phase Set the baking temperature to 250℃ and the heating rate to 0.5℃ / min.

[0057] After the heating phase begins, the baking of each sputtering ion pump is started simultaneously.

[0058] After the heating process lasted for about 7.5 hours, the system temperature reached 250℃, and then entered the heat preservation stage.

[0059] 2. Insulation stage: The insulation temperature is 250℃, and the insulation time is 48 hours. After 10 hours of heat preservation, turn on the power supply of each sputtering ion pump and confirm that the power supply of each sputtering ion pump is working properly.

[0060] Within 3 hours after the sputtering ion pump power supply starts normally, turn on the power supply of each titanium sublimation pump and degas the titanium wire of the titanium sublimation pump.

[0061] After the titanium sublimation pump power supply has been running for 6 hours, the ultra-high vacuum gauge is turned on. This ultra-high vacuum gauge is installed near the synchrotron 300 on the injection line and is used to detect the actual vacuum level of the injection line.

[0062] Before the end of the heat preservation stage, turn on the heating power of NEG pump 133 and heat the getter from room temperature to 550°C at a heating rate of 13°C / min. Then, keep the temperature at 550°C for 1 hour to complete the activation process of NEG pump 133.

[0063] During the heat preservation stage, ensure that the baking control system, sputtering ion pump power supply, titanium sublimation pump power supply, NEG pump 133 power supply, and ultra-high vacuum gauge are all in normal operating condition.

[0064] 3. Cooling stage After the heat preservation stage, the system cools down at a rate of 0.5℃ / min; at the same time, the heating power supply of the sputtering ion pump and the NEG pump 133 are disconnected, and the sputtering ion pump and NEG pump 133 cool down synchronously.

[0065] When the system temperature drops to 170°C, stop the degassing operation of all titanium sublimation pumps and switch them to sublimation mode.

[0066] After sublimation is completed, the first control valve 142 and the first molecular pump 141 are closed to isolate the first vacuum chamber 111 from the first roughing pump unit 140.

[0067] When the baking temperature drops below 60℃, the baking control system is turned off, and the cooling process ends.

[0068] After the system temperature drops to room temperature and remains at that temperature for a preset time, the titanium sublimation pump can be sublimated again to enhance its pumping performance.

[0069] For example, the baking process includes a heating stage, a holding stage, and a cooling stage, each stage being fully automatically controlled by the baking control system, specifically including the following steps: 1. Heating Phase The baking temperature is set to 200℃, and the heating rate is 0.3℃ / min.

[0070] After the heating phase begins, the baking of each sputtering ion pump is started simultaneously.

[0071] After the heating process lasted for about 7 hours, the system temperature reached 200℃, and then entered the heat preservation stage.

[0072] 2. Insulation stage: The insulation temperature is 200℃ and the insulation time is 40 hours.

[0073] After 8 hours of heat preservation, turn on the power supply of each sputtering ion pump and confirm that the power supply of each sputtering ion pump is working properly.

[0074] Within 1 hour after the sputtering ion pump power supply starts normally, turn on the power supply of each titanium sublimation pump to degas the titanium wire of the titanium sublimation pump.

[0075] After the titanium sublimation pump power supply has been running for a period of time, turn on the ultra-high vacuum gauge. This ultra-high vacuum gauge is installed near the synchrotron 300 on the injection line and is used to detect the actual vacuum level of the injection line.

[0076] Before the end of the heat preservation stage, turn on the heating power of NEG pump 133 and heat the getter from room temperature to 500°C at a heating rate of 10°C / min. Then, keep the temperature at 500°C for 1.5 hours to complete the activation process of NEG pump 133.

[0077] During the heat preservation stage, ensure that the baking control system, sputtering ion pump power supply, titanium sublimation pump power supply, NEG pump 133 power supply, and ultra-high vacuum gauge are all in normal operating condition.

[0078] 3. Cooling stage After the heat preservation stage, the system cools down at a rate of 0.3℃ / min; at the same time, the heating power supply of the sputtering ion pump and the heating power supply of NEG pump 133 are disconnected, and the sputtering ion pump and NEG pump 133 cool down synchronously.

[0079] When the system temperature drops to 180°C, stop the degassing operation of all titanium sublimation pumps and switch them to sublimation mode.

[0080] After sublimation is completed, the first control valve 142 and the first molecular pump 141 are closed to isolate the first vacuum chamber 111 from the first roughing pump unit 140.

[0081] When the baking temperature drops below 60℃, the baking control system is turned off, and the cooling process ends.

[0082] After the system temperature drops to room temperature and remains at that temperature for a preset time, the titanium sublimation pump can be sublimated again to enhance its pumping performance.

[0083] For example, the baking process includes a heating stage, a holding stage, and a cooling stage, each stage being fully automatically controlled by the baking control system, specifically including the following steps: 1. Heating Phase The baking temperature is set to 300℃, and the heating rate is 0.7℃ / min.

[0084] After the heating phase begins, the baking of each sputtering ion pump is started simultaneously.

[0085] After the heating process lasted for about 8 hours, the system temperature reached 300℃, and then entered the heat preservation stage.

[0086] 2. Insulation stage: The insulation temperature is 300℃ and the insulation time is 50h.

[0087] After 12 hours of heat preservation, turn on the power supply of each sputtering ion pump and confirm that the power supply of each sputtering ion pump is working properly.

[0088] Within 5 hours after the sputtering ion pump power supply starts normally, turn on the power supply of each titanium sublimation pump and degas the titanium wire of the titanium sublimation pump.

[0089] After the titanium sublimation pump power supply has been running for a period of time, turn on the ultra-high vacuum gauge. This ultra-high vacuum gauge is installed near the synchrotron 300 on the injection line and is used to detect the actual vacuum level of the injection line.

[0090] Before the end of the heat preservation stage, turn on the heating power of NEG pump 133 and heat the getter from room temperature to 600°C at a heating rate of 15°C / min. Then, keep the temperature at 600°C for 0.5 h to complete the activation process of NEG pump 133.

[0091] During the heat preservation stage, ensure that the baking control system, sputtering ion pump power supply, titanium sublimation pump power supply, NEG pump 133 power supply, and ultra-high vacuum gauge are all in normal operating condition.

[0092] 3. Cooling stage After the heat preservation stage, the system cools down at a rate of 0.7℃ / min; at the same time, the heating power supply of the sputtering ion pump and the heating power supply of NEG pump 133 are disconnected, and the sputtering ion pump and NEG pump 133 cool down synchronously.

[0093] When the system temperature drops to 190℃, stop the degassing operation of all titanium sublimation pumps and switch them to sublimation mode.

[0094] After sublimation is completed, the first control valve 142 and the first molecular pump 141 are closed to isolate the first vacuum chamber 111 from the first roughing pump unit 140.

[0095] When the baking temperature drops below 60℃, the baking control system is turned off, and the cooling process ends.

[0096] After the system temperature drops to room temperature and remains at that temperature for a preset time, the titanium sublimation pump can be sublimated again to enhance its pumping performance.

[0097] like Figure 1 and Figure 2 As shown, in some embodiments of the present invention, the number of first assembly units 110 is at least two, and two first vacuum chambers 111 are sequentially connected in series along the beamline. In other words, two first vacuum chambers 111, a plurality of second vacuum chambers 121, and a third vacuum chamber 131 are sequentially connected in series along the beamline. This series connection arrangement at the injection line inlet end can improve the pumping capacity at the injection line front end.

[0098] In some embodiments of the present invention, the number of second assembly units 120 is four, and the four second vacuum chambers 121 are connected in series along the beam line, which can improve the pumping capacity in the middle of the injection line.

[0099] For example, the synchrotron injection line 100 includes two first combined units 110, four second combined units 120, a third combined unit 130, a first roughing pump unit 140, and a valve group 150. Two first vacuum chambers 111, four second vacuum chambers 121, and a third vacuum chamber 131 are arranged in series along the beamline. This series structure, consisting of seven independent vacuum chambers, divides the entire injection line into multiple continuous differential pumping sections, distributing the total pressure drop from the inlet to the outlet across each section to establish a stepped vacuum distribution along the path. The beam enters the injection line from the first first vacuum chamber 111, which is directly connected to the linear injector 200, and then sequentially passes through the second first vacuum chamber 111, the four second vacuum chambers 121, and the third vacuum chamber 131 before entering the synchrotron 300. This beam path configuration ensures that the particle beam passes through a progressively decreasing vacuum environment created by the aforementioned multi-stage pumping structure during transmission. This stepped pressure reduction method provides favorable conditions for suppressing beam loss caused by residual gas scattering during particle beam injection.

[0100] In some embodiments of the invention, the number of second titanium sublimation pumps 123 in the second assembly unit 120 directly connected to the third vacuum chamber 131 is greater than the number of second titanium sublimation pumps 123 in other second assembly units 120. This arrangement provides a higher pumping rate in the upstream section adjacent to the third vacuum chamber 131 compared to other sections of the second assembly unit 120, enabling more effective capture and removal of residual gas molecules migrating from the upstream vacuum chamber along the beamline. This reduces the gas flux entering the third vacuum chamber 131, supporting the maintenance of an extremely high vacuum environment at the injection line outlet.

[0101] In some embodiments of the present invention, the synchrotron injection line 100 further includes a fourth assembly unit 160; the fourth assembly unit 160 includes a fourth vacuum chamber 161 and a fourth titanium sublimation pump 162 disposed in the fourth vacuum chamber 161; the fourth vacuum chamber 161 is connected in series between two adjacent second vacuum chambers 121 along the beamline. This design, by inserting a dedicated pumping unit in the middle of the injection line, forms a supplementary pumping section between the two second vacuum chambers 121, and uses the fourth titanium sublimation pump 162 to pump air from this local area to further reduce the pressure in this section and adjust the vacuum gradient distribution along the entire injection line.

[0102] Furthermore, the synchrotron injection line 100 also includes a second roughing pump unit 170; the second roughing pump unit 170 includes a second mechanical pump, a second molecular pump 171 and a second control valve 172; the second molecular pump 171 is installed in the fourth vacuum chamber 161, and the inlet of the second molecular pump 171 is connected to the inner cavity of the fourth vacuum chamber 161, the second mechanical pump is connected to the outlet of the second molecular pump 171, and the second control valve 172 is used to open or close the inlet of the second molecular pump 171.

[0103] By adding an independent evacuation port in the middle of the injection line, which works in conjunction with the first roughing pump unit 140 located at the inlet end, coordinated evacuation of the long-distance injection line vacuum system can be achieved. This reduces the impact of airflow conduction limitations on the evacuation rate and shortens the time required for the system to reach a high vacuum state from atmospheric pressure. When the second control valve 172 switches from the open state to the closed state, it isolates the inner cavity of the second roughing pump unit 170 from that of the fourth vacuum chamber 161 to prevent gas from the roughing pump system from flowing back into the injection line, thereby maintaining the ultra-high vacuum environment inside the injection line.

[0104] In some embodiments of the present invention, valve assembly 150 further includes a quick-closing valve 153. The quick-closing valve 153 is located at the inlet of the first valve 151. When the actual vacuum level of the linear injector 200 is lower than a preset threshold, the quick-closing valve 153 switches from an open state to a closed state to achieve vacuum isolation and protect the vacuum environment of the ion accelerator vacuum system. When a sudden situation such as vacuum deterioration occurs in the upstream linear injector 200, the quick-closing valve 153 can respond quickly and close, cutting off the gas passage in a short time and limiting the impact of vacuum deterioration to the linear injector 200 side, thus avoiding impact and damage to the vacuum environment of the synchrotron injection line 100 and the synchrotron 300.

[0105] Optionally, the response time of the quick-closing valve 153 is less than 15 milliseconds.

[0106] In some embodiments of the present invention, the synchrotron injection line 100 further includes a plurality of vacuum conduits 181 and a plurality of bellows 182. The vacuum conduits 181 connect the various vacuum chambers, forming the main channel for beam transport. The bellows 182, as flexible connectors, are designed to allow for a certain amount of deformation in the axial, lateral, and angular directions; this characteristic is used to compensate for minor positional deviations that may occur during the installation and alignment of the vacuum chambers and conduits. Simultaneously, during system baking, the bellows 182 can absorb dimensional changes caused by thermal expansion and contraction, thereby reducing the stress on the flange sealing surface and maintaining the vacuum seal of the connection.

[0107] The first vacuum chamber 111, the second vacuum chamber 121, and the third vacuum chamber 131 are connected in series via vacuum pipe 181 and bellows 182, combining the separate vacuum chambers into a complete and continuous vacuum system, providing an uninterrupted vacuum channel for the transmission of the particle beam from the injection line inlet to the outlet.

[0108] Optionally, any two vacuum chambers can be connected in series via a bellows 182 and a vacuum pipe 181. In other words, the two first vacuum chambers 111, the first vacuum chamber 111 and the second vacuum chamber 121, any two second vacuum chambers 121, the second vacuum chamber 121 and the third vacuum chamber 131, and the second vacuum chamber 121 and the fourth vacuum chamber 161 are all connected via a bellows 182 and a vacuum pipe 181.

[0109] Specifically, the connections of vacuum pipe 181, bellows 182, and each vacuum chamber are all achieved through flange interfaces. An oxygen-free copper gasket is placed between the mating ends of each pair of flanges. When two corresponding flanges are tightened with bolts, the gasket is compressed and undergoes plastic deformation, filling the microscopic unevenness on the flange sealing surface, thereby forming a reliable metal-to-metal seal to achieve the vacuum tightness required by the system.

[0110] During assembly, vacuum pipe 181, bellows 182, and each vacuum chamber are connected together by mating and fastening their respective flanges. Furthermore, to ensure smooth particle beam transmission, assembly precision is strictly controlled, requiring the coaxiality error between the beamline center axis and the flange center axis in the beamline direction to be no greater than 0.5 mm. This ensures that the connected components form a smooth, aligned channel, providing the geometric conditions for stable particle beam transmission.

[0111] During flange connection operations, a torque wrench must be used, and the connecting bolts must be tightened step by step and evenly in a symmetrical sequence. This operating procedure ensures that the flange sealing surface is evenly pressurized, ensuring a reliable and durable vacuum-tight connection between the pipeline and the vacuum chamber.

[0112] In some embodiments of the present invention, the first vacuum chamber 111, the second vacuum chamber 121, the third vacuum chamber 131, the vacuum pipe 181, and the bellows 182 are all made of high-performance austenitic stainless steel. High-performance austenitic stainless steel has low magnetic permeability, high mechanical strength, and excellent cold and hot working and welding properties, which can meet the comprehensive requirements of ultra-high vacuum systems for structural dimensional stability, long-term airtightness, and low gas escape rate. After appropriate high-temperature degassing treatment, high-performance austenitic stainless steel has a low background gas escape rate, a characteristic that allows the synchrotron injection line 100 to achieve and maintain a 10 -10 The basis of materials for ultra-high vacuum environments at the Pa level.

[0113] Optionally, the first vacuum chamber 111, the second vacuum chamber 121, the third vacuum chamber 131, the vacuum pipe 181, and the corrugated pipe 182 are all made of high-quality 316L austenitic stainless steel.

[0114] In some embodiments of the present invention, the dimensional tolerances of the first vacuum chamber 111, the second vacuum chamber 121, the third vacuum chamber 131, and the vacuum pipe 181 are all no greater than 0.5 mm, and the form and position tolerances are all no greater than 0.5 mm. By controlling the machining precision of individual components, the flange interfaces of each component can achieve effective docking when multiple components are assembled sequentially along the beamline. This provides a foundation for the entire injection line system to ultimately achieve the collimation requirement (e.g., the coaxiality error of the flanges in the beamline direction is no greater than 0.5 mm). Simultaneously, this control of form and position tolerances, especially the control of the parallelism and perpendicularity of the flange end faces, creates conditions for the sealing gasket to be uniformly stressed during flange connection, ensuring a reliable vacuum airtight connection and laying the foundation for the smooth implementation of subsequent on-site assembly and connection processes.

[0115] In some embodiments of the present invention, the first vacuum chamber 111 includes a vacuum chamber body and a connecting pipe. One end of the connecting pipe is welded to the vacuum chamber body, and the other end is fitted with a flange for detachable connection with the flange of the vacuum pipe 181, the flange of other vacuum chambers, or the flange of the pump.

[0116] It should be noted that, to ensure the cleanliness and sealing of ultra-high vacuum components, the relevant manufacturing processes follow the procedures below: Welding operations are carried out in a vacuum cleanroom. This measure prevents dust particles or contaminants in the environment from adhering to the inner surface of the workpiece or melting into the weld during the welding process, thereby controlling the surface gas emission rate of the component from the source.

[0117] Internal welds are preferred to avoid the formation of gaps or sealed spaces on the vacuum side. These spaces can trap gas, which is then slowly released during subsequent vacuuming, creating a persistent, difficult-to-remove leak. If external welding is necessary due to structural limitations, complete penetration must be ensured. Defects such as gaps, incomplete penetration, slag inclusions, porosity, and incomplete welds are strictly prohibited to guarantee the weld's tightness and mechanical strength, preventing it from becoming a true leakage path.

[0118] At the same time, the welding layout should avoid cross-shaped welds, which can reduce the risk of welding defects caused by heat concentration and stress complexity, thereby reducing the potential for leakage.

[0119] After welding, the components must undergo tolerance checking and leak rate testing. These procedures verify that the thermal process of welding did not cause the workpiece's dimensional and positional tolerances to exceed design requirements, and confirm that the weld meets the specified airtightness standards. Only after passing the inspection can the component proceed to the next manufacturing process.

[0120] like Figure 1 and Figure 2 As shown, in some embodiments of the present invention, the synchrotron injection line 100 further includes a vacuum gauge tube 190; the vacuum gauge tube 190 is installed in the third vacuum chamber 131, or in the second vacuum chamber 121 near the third vacuum chamber 131, for detecting the vacuum level at the end of the injection line. This installation position is set for directly measuring the vacuum level at the end of the injection line, i.e., the position closest to the inlet of the synchrotron 300. This measurement value is used to judge whether the entire injection line has successfully established a vacuum level from 10... -6 Pa to 10 -10 The Pa vacuum gradient index provides direct data for verifying whether the vacuum level at the injection line outlet meets the inlet requirements of the synchrotron 300.

[0121] like Figure 3 As shown, a second aspect of the present invention provides an ion accelerator vacuum system, comprising a linear injector 200, a synchrotron injection line 100 of any of the above embodiments, and a synchrotron 300. The inlet of the first vacuum chamber 111 of the synchrotron injection line 100 is connected to the outlet of the linear injector 200, this connection forming a physical channel between the two subsystems. This allows the synchrotron injection line 100 to receive ions from a vacuum of approximately 10⁻⁶. -6 A particle beam from a linear injector 200, operating on the Pa scale, is used as the starting point for establishing a vacuum gradient transition. The third vacuum chamber 131 of the synchrotron injection line 100 is connected to the inlet of the synchrotron 300. This connection will allow the particle beam in the injection line to reach a vacuum gradient transition point of 10 Pa. -10The extremely high vacuum at the Pa level is connected to the synchrotron 300, ensuring that the vacuum environment at the injection line outlet matches the vacuum environment inside the synchrotron 300. This connection method is used to maintain the extremely high vacuum state inside the synchrotron 300 during particle beam injection, providing the necessary vacuum conditions for the long-term cyclic acceleration of particles within it.

[0122] The ion accelerator vacuum system of this embodiment includes the synchrotron injection line 100 provided in any of the above embodiments, and therefore has at least the advantages described above, which will not be repeated here.

[0123] like Figure 4 As shown, the third aspect of the present invention provides a method for constructing a synchrotron injection line, used to construct the synchrotron injection line of any of the above embodiments. The method for constructing the synchrotron injection line includes: S100, ultra-high vacuum manufacturing; S200, integrated installation; S300, full-line sealing leak detection; S400, baking treatment.

[0124] S100, ultra-high vacuum manufacturing includes the following steps: S110, vacuum components are made of high-performance austenitic stainless steel; the vacuum components include a first vacuum chamber, a second vacuum chamber, a third vacuum chamber, a fourth vacuum chamber, and vacuum pipes; the dimensional tolerance of the vacuum components is no greater than 0.5 mm, and the form and position tolerance is no greater than 0.5 mm.

[0125] Optionally, high-performance austenitic stainless steel may be used to manufacture vacuum components, including: S111. High-performance austenitic stainless steel plates and pipes are selected as raw materials. High-performance austenitic stainless steel has low magnetic permeability, high mechanical strength, and excellent cold and hot working and welding performance, which can meet the comprehensive requirements of ultra-high vacuum systems for structural dimensional stability, long-term airtightness and low gas escaping rate.

[0126] S112. Utilize raw materials to machine various vacuum components such as vacuum chambers, vacuum pipes, and flanges. Strictly control the dimensional tolerances and form and position tolerances of each component to no more than 0.5mm during the machining process, ensuring assembly accuracy between components and providing a reliable foundation for subsequent welding and assembly processes. Furthermore, for the entire machining process of ultra-high vacuum (UHV) components, the use of halogen-containing lubricants or cutting fluids is prohibited. This prevents contaminant adsorption and residue from the source, ensuring that subsequent cleaning processes can thoroughly remove machining media residues and meet the stringent surface cleanliness requirements of ultra-high vacuum systems.

[0127] S113. Perform ultrasonic cleaning on each vacuum component after machining to remove oil, metal shavings and machining residues attached to its surface, and ensure that the surface cleanliness of the components meets the requirements for use in ultra-high vacuum systems.

[0128] S114, Precision welding of main structure Precision welding of the main structure includes welding the vacuum chamber body and connecting pipes, as well as welding irregularly shaped vacuum pipes (such as rectangular vacuum pipes). Welding operations are carried out in a vacuum cleanroom. Internal welds are preferred; if external welding is necessary due to structural limitations, complete penetration must be ensured, and defects such as seams, incomplete penetration, slag inclusions, porosity, and false welds are strictly prohibited. Furthermore, the welding layout should avoid cross-shaped welds to reduce the effective venting area and lower the potential leakage risk. After welding, the components must undergo tolerance verification and leak rate testing; only those that pass the test proceed to the next process.

[0129] S120. Perform high-temperature degassing treatment on vacuum components. Specifically, place the welded vacuum chamber, vacuum pipes, and other vacuum components in a vacuum environment with a vacuum level better than 1.0 × 10⁻⁶. -3 In a vacuum furnace with a pressure of Pa, the material is held at 950°C for 1 hour to fully remove dissolved gases, mainly H2, from the material matrix and reduce the background gas release rate. Furthermore, the flange blanks also undergo the same 950°C degassing process before processing to control material venting at the source and ensure the overall ultra-high vacuum performance of the system.

[0130] S130. The degassed vacuum components are shaped to ensure their dimensional and geometric tolerances meet design requirements. Inside the vacuum cleanroom, the shaped vacuum components are assembled and welded to their corresponding flanges. The flanges undergo ultrasonic cleaning and high-temperature degassed treatment. To ensure ultra-high vacuum cleanliness and sealing performance, all welding processes are completed in the vacuum cleanroom, and bare hands are strictly prohibited from contacting the inner surface of the workpiece throughout the process to avoid surface contamination from sweat, grease, and other substances with high degassed rates. After welding, the workpieces are inspected for dimensions and leakage rate; those that pass inspection can proceed to the next process.

[0131] S140. Perform ultrasonic cleaning on the vacuum components after flange welding. Specifically, immerse the welded vacuum components in a 65°C weakly acidic aqueous solution for ultrasonic cleaning for approximately 15 minutes, followed by immersion in a 65°C weakly alkaline solution for ultrasonic cleaning for approximately 15 minutes. Finally, rinse repeatedly with running deionized water until no foam remains. This step removes welding residue, microparticles, and trace amounts of surface-adsorbed contaminants, ensuring that the cleanliness of the component's internal surface meets the requirements for use in ultra-high vacuum systems.

[0132] S150. Perform low-temperature degassing treatment on the vacuum components after ultrasonic cleaning. Specifically, place each vacuum component after ultrasonic cleaning in a vacuum environment with a vacuum level better than 1.0 × 10⁻⁶. -3 In a vacuum furnace of Pa, the components are held at 600°C for 1 hour to fully remove residual gases adsorbed during welding and cleaning, thereby further reducing the background gas emission rate of the material.

[0133] S160. In a vacuum cleanroom, perform dimensional, geometrical, and positional tolerance checks and leak rate tests on vacuum components that have undergone low-temperature degassing treatment. Control the dimensional tolerance of the vacuum components to be no greater than 0.5 mm, and the geometrical and positional tolerances to be no greater than 0.5 mm; check whether the overall leak rate is no greater than 5.0 × 10⁻⁶ mm. -8 Pa·L / s; if all are qualified, proceed to the next process. Specifically, in a vacuum clean room, the vacuum components that have undergone low-temperature degassing are subjected to dimensional inspection, geometric tolerance inspection, and leak rate inspection. The dimensional tolerance of the vacuum components is controlled to be no greater than 0.5 mm, and the geometric tolerance is no greater than 0.5 mm; the overall leak rate is checked to ensure it is no greater than 5.0 × 10⁻⁶. -8 Pa·L / s; If all tests are qualified, aluminum blind flanges are added to the flange ports of the vacuum chamber, vacuum pipeline and bellows for sealing, and high-purity nitrogen is filled into the vacuum chamber, vacuum pipeline and bellows for protective sealing.

[0134] S200, integrated installation includes the following steps: S210. If the inspection is passed, continue installing the baking and heating jackets for the vacuum pipelines in the vacuum cleanroom. Seal the flange ports of the vacuum pipelines and bellows with aluminum blind flanges, and fill the vacuum pipelines and bellows with high-purity nitrogen for protective sealing. Specifically, the sealing performance of vacuum components may be affected during transportation; therefore, a re-inspection of the vacuum components is necessary to ensure that the leakage rate meets design requirements before formal installation. The re-inspection process includes: removing the aluminum blind flanges at the flange ports in the vacuum cleanroom, re-testing the leakage rate of the vacuum components, and checking that the overall leakage rate does not exceed 5.0 × 10⁻⁶. -8 Pa·L / s; If the above inspection is qualified, the baking heating jacket of the vacuum pipeline is installed in the vacuum clean room, aluminum blind flanges are re-sealed on the flange ports of the vacuum pipeline and corrugated pipe, and high-purity nitrogen is refilled into the vacuum pipeline and corrugated pipe for protective sealing.

[0135] If the inspection is passed, the vacuum chamber, vacuum measuring elements, beam diagnostic elements, and vacuum valves are integrated and assembled in the vacuum cleanroom to form an assembly module. The assembly module undergoes a comprehensive leak test. After confirming the leak rate is acceptable, aluminum blind flanges are sealed at the remaining flange ports of the assembly module, and high-purity nitrogen is injected for protection. It should be noted that the vacuum chamber, vacuum piping, and bellows are also first leak-tested in the cleanroom. After passing the leak test, they are assembled with the vacuum measuring elements, beam diagnostic elements, and vacuum valves. After assembly, the assembly module is leak-tested again, and after passing the leak test, blind flanges are added and nitrogen is injected for protection.

[0136] S220. After sealing, the assembly module is aligned at the installation site to ensure that the coaxiality error between the beam line center axis and the flange center axis in the beam line direction is no more than 0.5mm. Finally, flange docking connections are made for adjacent components such as vacuum pipes, bellows, and assembly modules. All flange docking connections are carried out in a closed environment within the mobile cleanroom.

[0137] Optionally, the process flow for flange butt connection is as follows: (1) Pre-cleaning treatment: Use a vacuum cleaner to dry clean the area around the flange connection end to remove micro-particle impurities.

[0138] (2) Blind flange removal: Slowly remove the aluminum blind flange covering the beam line flange port to expose the sealing flange end face.

[0139] (3) Surface wiping treatment: High-purity anhydrous ethanol with a purity of not less than 99.7% is used in conjunction with a dust-free wiping cloth to finely wipe the flange sealing surface and oxygen-free copper gasket to remove adsorbed microparticles and other residual contaminants. Throughout the wiping process, it is strictly forbidden to directly contact the sealing working surface with bare hands or wearing contaminated gloves, so as to eliminate the residue of high-emission contaminants such as sweat, grease and particulate matter from the source, prevent secondary pollution of the sealing surface, and ensure the ultra-high vacuum performance of the system.

[0140] (4) Sealing and fastening: Use a constant torque wrench to tighten the flange connection bolts symmetrically and evenly to ensure that the sealing surface is evenly stressed and to achieve a vacuum airtight connection.

[0141] S300, Full-line sealing leak detection. Specifically, after on-site integration and installation, the ion accelerator vacuum system undergoes vacuum evacuation and leak detection. The system is evacuated using the first and / or second roughing pump units until the vacuum level is better than 1.0 × 10⁻⁶. -4 After Pa, a high-sensitivity helium mass spectrometer is used to perform a full-area leak test on all flange sealing surfaces of the system. If a leak is found, the gaskets need to be tightened again or replaced with oxygen-free copper gaskets until no leaks are found in the system.

[0142] S400, Baking Treatment. Specifically, after leak detection, the vacuum chamber baking jacket is installed, the baking control system is debugged and its functions are verified simultaneously, and the synchrotron injection line is baked to reduce the gas escaping rate on the material surface.

[0143] Optionally, the baking process includes a heating stage, a holding stage, and a cooling stage, each of which is fully automatically controlled by the baking control system, specifically including the following steps: 1. Heating Phase Set the baking temperature to T1 and the heating rate to V1. Optionally, T1 can be set to 200-300 degrees Celsius (°C); V1 can be set to 0.3-0.7 degrees Celsius per minute (°C / min).

[0144] After the heating phase begins, the baking of each sputtering ion pump is started simultaneously.

[0145] After the heating process lasts for approximately time t1, the system temperature reaches T1, and then enters the heat preservation stage. Optionally, the value of t1 can range from 7 to 8 hours (h). 2. Insulation Stage: The insulation temperature is T1, and the insulation time is t2. Optionally, t2 can be set between 40 and 50 degrees Celsius, in hours (h).

[0146] After entering the heat preservation stage (t3 time), turn on the power supply of each sputtering ion pump and confirm that the power supply of each sputtering ion pump is working properly. Optionally, the value of t3 can be 8~12 hours (h).

[0147] Within 1 to 5 hours after the sputtering ion pump power supply is started normally, turn on the power supply of each titanium sublimation pump to degas the titanium wire of the titanium sublimation pump.

[0148] After the titanium sublimation pump power supply has been running for a period of time, the ultra-high vacuum gauge is turned on. This ultra-high vacuum gauge is installed near the synchrotron on the injection line and is used to detect the actual vacuum level of the injection line.

[0149] Before the end of the heat preservation stage, turn on the heating power of the NEG pump and heat the getter from room temperature to 500℃~600℃ at a heating rate of 10℃ / min~15℃ / min. Then, keep the temperature at 500℃~600℃ for 0.5 h~1.5 h to complete the activation process of the NEG pump.

[0150] During the heat preservation stage, ensure that the baking control system, sputtering ion pump power supply, titanium sublimation pump power supply, NEG pump power supply, and ultra-high vacuum gauge are all in normal operating condition.

[0151] 3. Cooling stage After the heat preservation phase, the system cools down at a rate of V2; simultaneously, the heating power supplies of the sputtering ion pump and the NEG pump are disconnected, and the sputtering ion pump and the NEG pump cool down synchronously. Optionally, the value of V2 can range from 0.3 to 0.7, with units of degrees Celsius per minute (°C / min).

[0152] When the system temperature drops to 170℃~190℃, stop the degassing operation of all titanium sublimation pumps and switch them to sublimation mode.

[0153] After sublimation is complete, the first control valve and the first molecular pump are shut off to isolate the first vacuum chamber from the first roughing pump unit.

[0154] When the baking temperature drops below 60℃, the baking control system is turned off, and the cooling process ends.

[0155] After the baking process, once the injection wire has cooled to room temperature, the vacuum level at the test point of the injection wire (near the second vacuum chamber of the synchrotron) reaches 10. -10 The Pa level, at which point the average vacuum of the linear injector is 10. -6 The Pa level, and the average vacuum of the synchrotron are 10. -10 The Pa level indicates that the vacuum level in each region has reached the preset target value. To verify the vacuum transition performance of the injection line, the first and second valves were opened to connect the entire injection line with the linear injector and synchrotron. After connection, the measurement point of the injection line remained at 10. -10 The average vacuum level of the linear injector remains at the Pa level, still in the range of 10 Pa. -6 The Pa level is still around 10, and the average vacuum level of the synchrotron is still 10. -10 The vacuum level is on the order of Pa. Therefore, after the first and second valves are opened, the vacuum level of the synchrotron is stably maintained at 10 Pa. -10 Pa level, not affected by the 10 Pa outlet of the linear injector -6 Interference from the Pa-level vacuum environment. The synchrotron injection line in this embodiment effectively ensures the stability of the synchrotron vacuum environment. Within a limited length of 20m, the injection line successfully achieved a 10m injection from the inlet end. -6 Pa to the outlet end 10 -10 The vacuum gradient transition over a wide range of Pa is smooth, the vacuum fluctuation is within the allowable range, and the synchrotron vacuum system operates stably and reliably.

[0156] To achieve 10 -6 Pa to 10 -10 This invention provides a comprehensive, engineerable, short-distance, wide-range vacuum gradient smooth transition solution on the Pa scale. Specific embodiments of the invention employ a synergistic optimization approach across three dimensions: vacuum system layout and pumping, ultra-high vacuum manufacturing, and precision integrated installation. This results in a stable, engineering-compliant solution that ensures the stability of the synchrotron vacuum environment, suppresses beam interference, and guarantees the stable passage of the particle beam through the vacuum transition section in a single pass. The proposed approach and implementation method are highly applicable and scalable, providing a general technical solution for short-distance, multi-scale vacuum gradient transitions in various ion accelerator devices.

[0157] Example 1 In this embodiment, the synchrotron injection line 100 is 15.4 meters long. Based on physical requirements and under the premise of axial space constraints, the layout of various components of the vacuum system and the pumping scheme are planned to achieve a length of 15.4 meters from the inlet end to the outlet end of the injection line.-6 Pa to 10 -10 A wide-range vacuum gradient transition (Pa) provides the necessary vacuum environment for particle beam transport while ensuring the stability of the synchrotron vacuum environment. Based on ensuring the transition target is achieved, the relative installation positions of each vacuum component are planned to avoid structural interference between components and the formation of vacuum dead zones, ensuring stable and coordinated operation of all components and maximizing the use of axial space to achieve a compact layout.

[0158] like Figure 1 As shown, the synchrotron injection line of this embodiment includes two first assembly units, four second assembly units, one third assembly unit, one fourth assembly unit, a first roughing pump unit, a valve group, a second roughing pump unit, a quick-closing valve, multiple vacuum pipes, and multiple bellows.

[0159] The system comprises two first vacuum chambers, four second vacuum chambers, one third vacuum chamber, and one fourth vacuum chamber, connected in series via vacuum pipes and bellows. Two titanium sublimation pumps are installed in the second vacuum chamber connected to the third vacuum chamber, while the remaining second vacuum chambers each have one titanium sublimation pump (TSP). The TSP pumps have a pumping speed of 3500 L / s and are primarily used for hydrogen evacuation within the injection line. Each of the first, second, and third vacuum chambers is equipped with a sputtering ion pump (SIP), with the first sputtering ion pump having an ultimate vacuum rating better than 1.0 × 10⁻⁶. -8 The ultimate vacuum specification of the second sputtering ion pump is better than 1.0 × 10 Pa. - 9 During operation, the first sputtering ion pump operates at a speed of 320 L / s, and the second sputtering ion pump operates at a speed of 300 L / s. The ultimate vacuum of the NEG pumps is better than 1.0 × 10⁻⁶. -9 Pa, with a pumping speed of 3600 L / s. This creates a gradient pumping layout along the direction of the beam line (from the inlet to the outlet). Utilizing the advantages of the NEG pump—high pumping speed, high suction capacity, small size, and easy installation—a composite pump unit is employed to enhance the end-stage vacuum pumping and maintenance capabilities.

[0160] The pumping speed of the first and second mechanical pumps is 4 L / s, and the pumping speed of the first and second molecular pumps is 550 L / s, which can quickly pump the vacuum level of the injection line to the target coarse pumping pressure (e.g., 10). -4 (Pa), which provides the basis for subsequent vacuum acquisition and system leak detection.

[0161] The synchrotron injection line splicing method in this embodiment includes: S100, ultra-high vacuum manufacturing; S200, integrated installation; S300, full-line leak detection; S400, baking treatment. After baking treatment, once the injection line has cooled to room temperature, the vacuum level at the measuring point (the second vacuum chamber near the injection line outlet) is 5.7 × 10⁻⁶. -10 At this point, the average vacuum level of the linear injector is 1.9 × 10⁻⁶ Pa. -6 Pa, the average vacuum level of the synchrotron is 6.8 × 10⁻⁶. -10 The vacuum level in each region reached the preset target value. To verify the vacuum transition performance of the injection line, the quick-closing valve, the first valve, and the second valve were opened to connect the entire injection line with the linear injector and the synchrotron. After connection, the vacuum level at the measurement point was 8.4 × 10⁻⁶ Pa. -10 Pa, the average vacuum of the linear injector is 1.3 × 10⁻⁶. -6 Pa, the average vacuum level of the synchrotron is 8.6 × 10⁻⁶. -10 Pa.

[0162] This shows that after the valve is opened, the vacuum level of the synchrotron is stably maintained at 10. -10 Pa level, not affected by the 10 at the import end -6 The above results demonstrate that the vacuum transition structure effectively ensures the stability of the synchrotron vacuum environment. The injection line, within a limited length of 15.4 m, successfully achieved a 10 Pa-level vacuum environment from the inlet end. -6 Pa to the outlet end 10 - 10 The system operates with a wide vacuum gradient transition, a smooth transition process, and vacuum fluctuations within permissible limits, ensuring stable and reliable system operation.

[0163] Finally, it should be noted that the above embodiments are only for illustrating the present invention and not for limiting the present invention. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that various combinations, modifications, or equivalent substitutions of the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention and should be covered within the scope of the claims of the present invention.

Claims

1. A synchrotron injection line, characterized in that, include: The first assembly unit (110) includes a first vacuum chamber (111), a first sputtering ion pump (112), and a first titanium sublimation pump (113); the first sputtering ion pump (112) and the first titanium sublimation pump (113) are both installed in the first vacuum chamber (111); the inlet of the first vacuum chamber (111) is used to connect to the outlet of the linear injector (200); Multiple second assembly units (120) are provided, each including a second vacuum chamber (121), a second sputtering ion pump (122), and a second titanium sublimation pump (123). Both the second sputtering ion pump (122) and the second titanium sublimation pump (123) are installed in the second vacuum chamber (121). The ultimate vacuum of the second sputtering ion pump (122) is better than 1.0 × 10⁻⁶. -9 Pa, the ultimate vacuum index of the second sputtering ion pump (122) is better than that of the first sputtering ion pump (112); The third assembly unit (130) includes a third vacuum chamber (131), a third sputtering ion pump (132), and a NEG pump (133); both the third sputtering ion pump (132) and the NEG pump (133) are installed in the third vacuum chamber (131); the outlet of the third vacuum chamber (131) is used to connect to the inlet of the synchrotron (300), and the ultimate vacuum parameters of both the third sputtering ion pump (132) and the NEG pump (133) are better than 1.0 × 10⁻⁶. -9 Pa; the first vacuum chamber (111), a plurality of second vacuum chambers (121) and the third vacuum chamber (131) are connected in series along the beamline; The first roughing pump unit (140) includes a first mechanical pump, a first molecular pump (141) and a first control valve (142); the first molecular pump (141) is installed in the first vacuum chamber (111) and the inlet of the first molecular pump (141) is connected to the inner cavity of the first vacuum chamber (111); the first mechanical pump is connected to the outlet of the first molecular pump (141); and the first control valve (142) is used to open or close the inlet of the first molecular pump (141). The valve assembly (150) includes a first valve (151) and a second valve (152); the first valve (151) is located at the inlet of the first vacuum chamber (111) and is used to open or close the inlet of the first vacuum chamber (111); the second valve (152) is located at the outlet of the third vacuum chamber (131) and is used to open or close the outlet of the third vacuum chamber (131).

2. The synchrotron injection line according to claim 1, characterized in that, The number of the first assembly unit (110) is at least two, and the two first vacuum chambers (111) are connected in series along the beam line; The number of the second assembly unit (120) is 4, and the 4 second vacuum chambers (121) are connected in series along the beam line.

3. The synchrotron injection line according to claim 1, characterized in that, The number of second titanium sublimation pumps (123) of the second assembly unit (120) connected to the third vacuum chamber (131) is greater than the number of second titanium sublimation pumps (123) of the other second assembly units (120).

4. The synchrotron injection line according to claim 1, characterized in that, Also includes: The fourth assembly unit (160) includes a fourth vacuum chamber (161) and a fourth titanium sublimation pump (162) disposed in the fourth vacuum chamber (161); the fourth vacuum chamber (161) is connected in series between two adjacent second vacuum chambers (121) along the beam line.

5. The synchrotron injection line according to claim 4, characterized in that, Also includes: The second roughing pump unit (170) includes a second mechanical pump, a second molecular pump (171) and a second control valve (172); the second molecular pump (171) is installed in the fourth vacuum chamber (161) and the inlet of the second molecular pump (171) is connected to the inner cavity of the fourth vacuum chamber (161), the second mechanical pump is connected to the outlet of the second molecular pump (171), and the second control valve (172) is used to open or close the inlet of the second molecular pump (171).

6. The synchrotron injection line according to claim 1, characterized in that, The valve assembly (150) also includes: A quick-closing valve (153) is installed at the inlet of the first valve (151). When the actual vacuum level of the linear injector (200) is lower than a preset threshold, the quick-closing valve (153) switches from the open state to the closed state to achieve vacuum isolation.

7. The synchrotron injection line according to any one of claims 1 to 6, characterized in that, Also includes: Multiple vacuum pipes (181) and multiple corrugated pipes (182) are provided, and the first vacuum chamber (111), the second vacuum chamber (121) and the third vacuum chamber (131) are connected in series through the vacuum pipes (181) and the corrugated pipes (182).

8. The synchrotron injection line according to claim 7, characterized in that, The first vacuum chamber (111), the second vacuum chamber (121), the third vacuum chamber (131), the vacuum pipe (181) and the corrugated pipe (182) are all made of high-performance austenitic stainless steel.

9. A vacuum system for an ion accelerator, characterized in that, include: Linear injector (200); The synchrotron injection line (100) according to any one of claims 1 to 8, wherein the inlet of the first vacuum chamber (111) of the synchrotron injection line (100) is connected to the outlet of the linear injector (200); Synchrotron (300), the inlet of which is connected to the third vacuum chamber (131) of the synchrotron injection line (100).

10. A method for constructing a synchrotron injection line, characterized in that, The method for constructing the synchrotron injection line according to any one of claims 1 to 8 includes ultra-high vacuum manufacturing, integrated installation, full-line leak detection and baking treatment; The ultra-high vacuum manufacturing process includes the following steps: The vacuum components are made of high-performance austenitic stainless steel; wherein, the vacuum components include a first vacuum chamber, a second vacuum chamber, a third vacuum chamber, a fourth vacuum chamber, and vacuum pipes; the dimensional tolerance of the vacuum components is no greater than 0.5 mm, and the form and position tolerance is no greater than 0.5 mm; The vacuum component is subjected to high-temperature degassing treatment; The vacuum component after degassing is straightened to ensure that its dimensional and geometric tolerances meet the design requirements; in a vacuum cleanroom, the straightened vacuum component is assembled and welded to the corresponding flange; wherein the flange is subjected to ultrasonic cleaning and high-temperature degassing treatment; The vacuum components, after flange welding, are subjected to ultrasonic cleaning. The vacuum component is subjected to low-temperature degassing after ultrasonic cleaning; In a vacuum cleanroom, the vacuum components, after undergoing low-temperature degassing, are subjected to dimensional, geometrical, and positional tolerance checks, as well as leak rate checks. The dimensional and geometrical tolerances of the vacuum components are controlled to be no greater than 0.5 mm; the overall leak rate is checked to ensure it does not exceed 5.0 × 10⁻⁶ mm. -8 Pa·L / s; The integrated installation includes the following steps: If the inspection is passed, continue to install the baking heating jacket of the vacuum pipeline in the vacuum clean room, cover the flange ports of the vacuum pipeline and the corrugated pipe with aluminum blind plates for sealing, and fill the vacuum pipeline and the corrugated pipe with high-purity nitrogen for protective sealing. If the test is passed, continue to complete the integrated assembly of vacuum chamber, vacuum measuring element, beam diagnostic element and vacuum valve in the vacuum clean room to form an assembly module; perform overall leak testing on the assembly module, and after confirming that the leak rate is qualified, cover the remaining flange port of the assembly module with aluminum blind plate seal and fill it with high-purity nitrogen for protection. The sealed assembly module is aligned at the installation site to ensure that the coaxiality error between the beam line center axis and the flange center axis in the beam line direction is no more than 0.5 mm. Finally, the flanges of adjacent components such as the vacuum pipe, the bellows, and the assembly module are connected. All flange connection processes are carried out in a closed mobile cleanroom.

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