Extremely thin vacuum transition device and pressure difference elimination system

Abstract

The present disclosure provides an ultra-thin vacuum transition device and pressure difference elimination system, which can be applied to the field of particle accelerator technology. The vacuum transition device comprises: a vacuum transition film configured as a non-metal film with a thickness less than 0.1 mm, two sealing connectors respectively arranged on both sides of the vacuum transition film and connected to a particle beam pipeline. The vacuum transition device can realize the transition of the vacuum gradient in a super wide range while greatly reducing the energy loss of the particle beam. The pressure difference elimination system can accurately control the pressure on both sides of the vacuum transition film during the vacuum pumping and air amplification stages, thereby eliminating the pressure difference on both sides of the vacuum transition film during use to avoid bearing a large gas pressure, which can significantly reduce the risk of film structure damage, greatly increase the service life of the vacuum transition film, and ensure that the ultra-thin film structure vacuum transition device can realize long-term safe and stable operation.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of particle accelerator vacuum technology, and in particular to an ultra-thin vacuum transition device and pressure difference elimination system. BACKGROUND

[0002] A vacuum transition device is a technology for realizing vacuum transition between different vacuum degree regions. In a particle accelerator (such as a heavy ion accelerator, a proton accelerator, and an electron accelerator), the required vacuum degree of a synchrotron is very high (better than 10 -9 mbar), while the required vacuum degree of a high-energy transport line is relatively low (10 -5 mbar). At this time, there is a four-order vacuum gradient difference between the synchrotron and the high-energy transport line, and a vacuum transition device is needed.

[0003] A conventional particle accelerator uses a differential pumping system to meet the requirement of vacuum gradient transition, and the differential pumping system needs multiple vacuum pump sections, so the cost and occupied space are large. A membrane structure (such as a metal membrane, a composite membrane of metal and non-metal, and a non-metal membrane) is a kind of vacuum transition device, which is used to limit the transmission of gas in the membrane structure while allowing particles (such as heavy ions, protons, and electrons) to pass through by setting a membrane structure between high vacuum degree and low vacuum degree. The non-metal membrane does not produce neutron contamination when the particles pass through the accelerator, so it has good radio physics performance. A conventional non-metal membrane vacuum transition device needs to withstand atmospheric pressure or the pressure difference during the vacuum system vacuumizing and air amplifying, resulting in a relatively thick membrane, especially for a large-area vacuum transition cross section, thereby causing large changes in the scattering angle, large changes in the emission degree, and large energy loss each time the particle beam passes through, resulting in a large reduction in the beam quality and the quality of the particle beam after passing through the membrane structure.

[0004] The ultra-thin membrane structure vacuum transition device can not only realize the transition of vacuum gradient of more than 9 orders of magnitude without occupying much installation space, but also more importantly, can reduce the influence on the quality of particle beam transmission process, thereby improving the overall performance index of the particle accelerator. While realizing the ultra-wide range vacuum gradient transition and reducing the influence on the particle transmission quality, accurate pressure control on both sides of the membrane structure and precise pressure difference control during the vacuum pumping and air amplification process are complex and important problems, and are also the key points for long-term safe and stable use of the ultra-thin membrane structure vacuum transition device in the particle accelerator. Realizing the ultra-wide range vacuum gradient transition, reducing the influence on the particle transmission quality, accurately controlling the pressure on both sides of the membrane structure, and precisely controlling the pressure difference on both sides of the membrane structure are the key points and difficulties in the development of the vacuum transition device of the particle accelerator. In order to realize the ultra-wide range vacuum gradient transition, the existing research and application of the non-metallic membrane structure vacuum transition device are all based on the requirement of mechanical strength to withstand the atmospheric pressure and the large pressure difference generated during the vacuum pumping and air amplification process. At present, there is no related research on the ultra-thin membrane structure vacuum transition device without considering the pressure difference during the atmospheric pressure and the vacuum pumping and air amplification process. The main reason is that the pressure that can be withstood by the ultra-thin membrane structure is very small (usually within 0.1 atmospheric pressure), and it is difficult to always meet the requirement of the low pressure difference on both sides of the ultra-thin membrane structure during the entire use process. Similarly, it is also difficult for the vacuum transition device in the particle accelerator to always meet the requirement of the low pressure difference on both sides of the ultra-thin membrane structure during the entire use process. At present, the research on the vacuum transition device of the particle accelerator realizes the requirement of the vacuum gradient transition through flow limiting and difference, and the influence on the energy loss performance index during the particle transmission process is also the key point of the research on the vacuum transition device. The ultra-thin membrane structure can greatly reduce the energy loss of the particle beam during the transmission process. The ultra-wide range vacuum transition, elimination of the influence of the performance parameters during the particle beam transmission process, and the use of the ultra-thin vacuum transition structure are the key points and difficulties in the development of the vacuum transition device of the particle accelerator.

[0005] The membrane structure vacuum transition device has unique pressure distribution, high ability to block gas transmission, and abnormally efficient structure, which cannot be compared with conventional vacuum transition devices. Due to the lack of in-depth research on accurate pressure control and precise control and elimination of pressure difference, the current particle accelerator cannot meet the requirements of the use of the ultra-thin membrane structure vacuum transition device.

[0006] Currently, the methods of the membrane structure vacuum transition device in research and use are all considering the bearing capacity of gas pressure to ensure long-term safe and stable use in the environment of pressure fluctuation, such as increasing the thickness of the membrane structure, using the membrane structure in combination with high-strength non-metallic structure, reducing the transmission efficiency of the particle beam, and thus unable to be used in the particle accelerator device which requires the particle beam to pass through the membrane structure with a small enough energy loss. The main purpose of the particle accelerator related research is to provide qualified particle beam quality, so that the performance index influence of the particle beam in the transmission process can be ignored. According to the current technical conditions, it is impossible to achieve, that is, the membrane structure vacuum transition device used in the particle accelerator at present cannot meet the requirements of the physical parameters when the beam passes through without being affected. SUMMARY

[0007] In view of the above problems, the present disclosure provides an extremely thin vacuum transition device and a pressure difference elimination system, which can realize vacuum gradient transition in a super wide range while greatly reducing the energy loss of the particle beam when passing through. By precisely controlling the pressure on both sides of the extremely thin vacuum transition device and the pressure difference, the pressure difference on both sides of the membrane structure during vacuum pumping and air amplification is eliminated, so that the extremely thin membrane structure vacuum transition device can realize long-term safe and stable operation.

[0008] According to a first aspect of the present disclosure, an extremely thin vacuum transition device applied to a particle beam pipeline is provided, and the extremely thin vacuum transition device comprises:

[0009] a vacuum transition membrane configured as a non-metallic membrane with a thickness less than 0.1 millimeter;

[0010] two sealing connectors respectively arranged on both sides of the vacuum transition membrane and connected to the particle beam pipeline.

[0011] According to an embodiment of the present disclosure, the sealing connector comprises:

[0012] a first flange configured to connect the vacuum transition membrane and the particle beam pipeline;

[0013] a sealing ring arranged between the vacuum transition membrane and the first flange and configured to seal the vacuum transition membrane.

[0014] According to an embodiment of the present disclosure, in the case that the atmospheric pressure is the front-stage pressure, the outgassing rate of the vacuum transition membrane is 10 -4 mbarL / s;

[0015] The vacuum transition range of the vacuum transition membrane is at least between 10 -11 mbar and 10 -2 mbar.

[0016] According to an embodiment of the present disclosure, at least one through hole is arranged on the vacuum transition film, and the number of the through holes is the same as the number of the fixing holes on the first flange;

[0017] The through holes are used for fixing the first flange to the vacuum transition film through the fixing holes.

[0018] According to an embodiment of the present disclosure, the thickness of the vacuum transition film is related to the energy loss requirement of the particle beam flow;

[0019] The area of the vacuum transition film is related to the area of the beam flow cross section required when the particle beam flow passes through the vacuum transition film.

[0020] A second aspect of the present disclosure provides a pressure difference elimination system, comprising:

[0021] The extremely thin vacuum transition device as described in the first aspect;

[0022] Two particle beam flow pipes are arranged on both sides of the extremely thin vacuum transition device and connected to the vacuum transition film through the sealing connector;

[0023] The pressure difference elimination device comprises flow guide assemblies arranged on the two particle beam flow pipes respectively and a vacuum pumping assembly, and the two flow guide assemblies are connected to the vacuum pumping assembly through a tee joint.

[0024] According to an embodiment of the present disclosure, one of the two particle beam flow pipes is connected to the sealing connector through a first bellows.

[0025] According to an embodiment of the present disclosure, the flow guide assembly comprises:

[0026] The angle valve comprises two interfaces, one of the two interfaces is connected to the particle beam flow pipe, and the other of the two interfaces is connected to a flow guide element;

[0027] The flow guide element comprises two second flanges and a pipe connecting the two second flanges, one of the two second flanges is connected to the other interface, and the other of the two second flanges is connected to the second bellows;

[0028] The second bellows comprises two interfaces, one of the two interfaces is connected to the other second flange, and the other of the two interfaces is connected to one of the interfaces of the tee joint.

[0029] According to an embodiment of the present disclosure, the length of the pipe connecting the two second flanges is related to the pressure control requirement in the vacuum pumping and air amplification stages;

[0030] In the case of simultaneous use of two flow guide elements, the flow guide elements control the pressure difference on both sides of the vacuum transition film during vacuum pumping and air release.

[0031] A third aspect of the present disclosure provides a particle accelerator, comprising the pressure difference elimination system according to the second aspect.

[0032] The present disclosure has the following advantages due to the above technical solutions:

[0033] (1) The extremely thin vacuum transition device does not need to consider the influence of mechanical strength, and can be made into an extremely thin structure, so that the influence on the beam is greatly eliminated, the structure is simple and compact, and has a broad application prospect.

[0034] (2) The vacuum transition of the two particle beam pipes only needs one layer of vacuum transition film, and the vacuum gradient transition demand in a super wide range can be realized, the cost is extremely low, the manufacturing process is simple, and it is easy to popularize.

[0035] (3) The use of two flow guide elements precisely controls the pressure difference on both sides of the vacuum transition film, so that the vacuum transition film does not need to consider the gas pressure during the entire use process, which can significantly reduce the risk of film structure damage and greatly increase the service life of the vacuum transition film.

[0036] (4) The pressure difference elimination system has the advantages of simple structure, easy processing and manufacturing, low cost, stable performance, easy popularization, and broad application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0037] The above and other objects, features and advantages of the present disclosure will become more apparent from the following description of embodiments of the present disclosure, taken in conjunction with the accompanying drawings, in which:

[0038] Figure 1 An exploded schematic view of an extremely thin vacuum transition device according to an embodiment of the present disclosure is schematically shown;

[0039] Figure 2 A schematic view of a vacuum transition film according to an embodiment of the present disclosure is schematically shown;

[0040] Figure 3 A schematic view of a pressure difference elimination system according to an embodiment of the present disclosure is schematically shown;

[0041] Figure 4 A schematic view of a flow guide element according to an embodiment of the present disclosure is schematically shown;

[0042] Figure 5 A pressure gradient distribution schematic view of a vacuum transition film according to an embodiment of the present disclosure is schematically shown;

[0043] Figure 6A schematic diagram of a relationship between pressure in a vacuuming phase and time is shown.

[0044] Figure 7 A schematic diagram of a relationship between pressure difference in a vacuuming phase and time is shown.

[0045] Figure 8 A schematic diagram of a relationship between pressure in a pressure amplification phase and time is shown.

[0046] Figure 9 A schematic diagram of a relationship between pressure difference in a pressure amplification phase and time is shown. DETAILED DESCRIPTION

[0047] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. It is to be understood, however, that the description is merely exemplary and is intended to provide a thorough understanding of the present disclosure. The following description includes specific details to provide a thorough understanding and enabling description of these embodiments. However, it will be obvious to those skilled in the art that these embodiments can be practiced without these specific details. In some instances, well-known structures and functions have been omitted so as not to obscure the concepts of the present disclosure with unnecessary detail.

[0048] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used herein, the term "includes" and tautological expressions thereof, such as "including," means the inclusion of but not limited to, and is not meant to be construed as a functionally limiting the scope of the embodiments.

[0049] All terms used herein, including technical and scientific terms, have the same meanings as commonly understood by one of ordinary skill in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning that is consistent with the context of the specification, and should not be interpreted in an idealized or overly formal way.

[0050] In the case where expressions similar to "at least one of A, B, and C, etc." are used, it is generally construed that the meaning is understood by one of ordinary skill in the art as it is commonly used (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, a system having B alone, a system having C alone, a system having both A and B, a system having both A and C, a system having both B and C, and / or a system having A, B, and C, etc.).

[0051] Figure 1 A schematic diagram of an exploded view of an ultra-thin vacuum transition device according to an embodiment of the present disclosure is shown.

[0052] AsFigure 1 As shown, the extremely thin vacuum transition device includes a vacuum transition film 1 and two sealing connectors. The vacuum transition film 1 is configured as a non-metal film with a thickness less than 0.1 mm, for realizing vacuum gradient transition and allowing particle beam flow to pass through. The two sealing connectors are respectively arranged on both sides of the vacuum transition film 1, and are both connected to the particle beam flow pipeline.

[0053] In an embodiment, a set of sealing connectors includes a first flange 3 configured to connect the vacuum transition film 1 and the particle beam flow pipeline, and a sealing ring 2 arranged between the vacuum transition film 1 and the first flange 3, and configured to seal the vacuum transition film 1 and assemble it to the particle beam flow transport line. The vacuum transition film 1 is connected to the first flange 3 through the sealing ring 2 to realize vacuum sealing.

[0054] Figure 2 A schematic diagram of a vacuum transition film according to an embodiment of the present disclosure is shown schematically.

[0055] As shown, the vacuum transition film 1 has 16 through holes distributed around the periphery. The 16 through holes are matched with 16 fixing holes of the first flange 3 for fixing and positioning the vacuum transition film 1. Figure 2

[0056] The vacuum transition film 1 is a non-metal film such as a Hostaphan film, a Mylar film or a Kapton film.

[0057] In an implementation, the performance parameters of the vacuum transition film 1 used in the present disclosure can be as shown in Table 1 below:

[0058] Table 1

[0059] Material name Hostaphan film Poisson ratio 0.4 Young's modulus 4.4E9 Pa Density 1.395 g / cm3 Ultimate yield strength 130 MPa Thickness 0.075 mm

[0060] In an embodiment of the present disclosure, the vacuum transition film 1 is used to realize vacuum gradient transition and beam flow transmission. Since the vacuum transition film 1 of the present disclosure is extremely thin, the loss in the beam flow transmission process can be ignored.

[0061] The vacuum transition film 1 of the present disclosure can realize transition from extremely high vacuum degree to medium vacuum degree. In the case of atmospheric pressure as the front stage pressure, the outgassing rate of the vacuum transition film 1 is 10 -4 mbarL / s. The range of vacuum transition is at least between 10 -11 mbar and 10 -2 mbar, i.e. the vacuum degrees on both sides of the vacuum transition film 1 can realize vacuum transition through the vacuum transition film 1 of the present disclosure.

[0062] ​In one embodiment of this disclosure, the thickness of the vacuum transition membrane 1 is related to the energy loss requirements of the particle beam and can be set according to actual application needs. Its thickness directly affects the energy loss when the beam passes through. The area of ​​the vacuum transition membrane 1 is related to the area of ​​the beam cross-section required when the particle beam passes through the vacuum transition membrane 1 and can be set according to actual application needs.

[0063] It should be noted that the shape and size of the vacuum transition membrane 1 can also be set according to actual application requirements to meet the dimensional requirements for beam passing through the vacuum transition membrane 1. For example... Figure 2 As shown in the example, the vacuum transition membrane 1 is circular in shape.

[0064] The effect of the vacuum transition membrane 1 used in this embodiment on the beam physical performance parameters is shown in Table 2 below:

[0065] Table 2

[0066] Indicator Influence result Particle through the angular rms (mrad) 0.257 Change in emittance 1.07 120 Mev / u energy loss (C particles) 0.18 Mev / u (0.15%) 400 Mev / u energy loss (C particles) 0.083 Mev / u (0.021%)

[0067] Figure 3 A schematic diagram of a pressure difference elimination system provided according to an embodiment of the present disclosure is shown.

[0068] like Figure 3 As shown, the pressure difference elimination system includes: an ultra-thin vacuum transition device, two particle beam pipes 5, and a pressure difference elimination device. The two particle beam pipes 5 are disposed on both sides of the ultra-thin vacuum transition device. The pressure difference elimination device includes flow guiding components and vacuum pumping components respectively disposed on the two particle beam pipes, and the two flow guiding components and the vacuum pumping components are connected by a T-junction.

[0069] One side of the vacuum transition membrane 1 is connected to the particle beam pipe 5 through a first flange 3, and the other side of the vacuum transition membrane 1 is connected to the particle beam pipe 5 through another first flange 3, thereby realizing the vacuum gradient transition between the two particle beam pipes 5.

[0070] In one embodiment, the ultrathin vacuum transition device is as follows: Figure 1 The ultra-thin vacuum transition device shown has two particle beam channels 5 positioned on either side of it, connected to the vacuum transition membrane 1 via a sealing connector. One particle beam channel 5 is connected to the sealing connector via a first bellows 6.

[0071] Optionally, the first flange 3 on one side of the vacuum transition membrane 1 is connected to the particle beam pipe 5 by argon arc welding, and the first flange 3 on the other side is connected to the first bellows 6 by argon arc welding. The first bellows 6 is connected to the particle beam pipe 5.

[0072] like Figure 3As shown, the flow guide assembly comprises an angle valve 8, a flow guide element 10 and a second bellow 11. The angle valve 8 comprises two interfaces, one of which is connected with the particle beam flow pipe 5, and the other of which is connected with the flow guide element 10.

[0073] As shown in FIG. 1, the flow guide element 10 comprises two second flanges 101 and a pipe 102 connecting the two second flanges 101, two ends of the pipe 102 being connected with the two second flanges 101 respectively, one of the two second flanges 101 being connected with the other interface, and the other of the two second flanges 101 being connected with the second bellow 11. Figure 3 4 As shown in FIG. 1, the flow guide element 10 comprises two second flanges 101 and a pipe 102 connecting the two second flanges 101, two ends of the pipe 102 being connected with the two second flanges 101 respectively, one of the two second flanges 101 being connected with the other interface, and the other of the two second flanges 101 being connected with the second bellow 11.

[0074] The flow guide element used in the embodiment can be customized and purchased from Beijing Uxin Vacuum Mall.

[0075] As shown in FIG. 1, the flow guide element 10 comprises two second flanges 101 and a pipe 102 connecting the two second flanges 101, two ends of the pipe 102 being connected with the two second flanges 101 respectively, one of the two second flanges 101 being connected with the other interface, and the other of the two second flanges 101 being connected with the second bellow 11. Figure 3 In an embodiment of the present disclosure, the length of the pipe 102 connecting the two second flanges 101 is related to the pressure control requirement in the vacuumizing and air amplifying stages. In the case of simultaneous use of two flow guide elements 10, the flow guide elements 10 control the pressure difference on both sides of the vacuum transition film 1 in the vacuumizing and air amplifying processes.

[0076] It can be understood that the lengths of the pipes 102 of the two flow guide elements 10 can be the same or different, and are set according to actual needs.

[0077] In an example, the inner diameter of the pipe 102 connecting the two second flanges 101 is 1 mm.

[0078] In the present disclosure, the models of each first flange 3 and second flange 101 can be the same or different, which is not limited in the present disclosure, and can be selected by those skilled in the art according to actual needs. For example, the two second flanges 101 included in the flow guide element 10 can respectively adopt a CF35 flange and a KF25 flange.

[0079] In an embodiment of the present disclosure, as shown in FIG. 1, the vacuumizing assembly comprises a tee joint 12, a diaphragm valve 13 and a vacuum pump 14. The two flow guide elements 10 are connected with the vacuum pump 14 through the second bellow 11, the tee joint 12 and the diaphragm valve 13.

[0080] Figure 3 The pressure difference elimination system provided by the present disclosure eliminates the pressure difference in the following manner:

[0081] The pressure difference elimination system provided by the present disclosure eliminates the pressure difference in the following manner:

[0082] ​​The length of the two flow conduct elements 10 is determined according to the need of pressure control in the vacuum pumping and atmosphere expanding stages. Then the vacuum pumping is performed by the vacuum pump 14, and then the atmosphere is expanded. After the vacuum pumping and atmosphere expanding stages, the angular valve 8 is closed to isolate the particle beam flow pipe 5 from the atmosphere environment.

[0083] Vacuum pumping: the vacuum pump 14 simultaneously pumps the particle beam flow pipe 5 on both sides of the vacuum transition membrane 1 through the flow conduct elements 10 on both sides of the vacuum transition membrane 1, and the gas inside the particle beam flow pipe 5 is exhausted.

[0084] Atmosphere expanding: only the vacuum pump 14 needs to be removed in the atmosphere expanding stage, and the two particle beam flow pipes 5 are simultaneously expanded through the two flow conduct elements 10 from the interface of the second bellows 11.

[0085] Wherein, after the vacuum pumping and atmosphere expanding stages, the two flow conduct elements 10 can be removed.

[0086] The pressure difference elimination method is used to eliminate the pressure difference on both sides of the vacuum transition membrane 1 in the vacuum pumping and atmosphere expanding stages, so that the vacuum transition membrane 1 hardly bears the pressure difference in the whole process of operation and use, and the mechanical strength factor is not considered, and the structure is extremely thin.

[0087] Figure 5 The pressure gradient distribution diagram of the vacuum transition membrane 1 provided by the embodiment of the present disclosure is schematically shown.

[0088] The stress values and the ratio to the ultimate yield stress of the vacuum transition membrane 1 used in the embodiment under different pressure difference conditions are shown in Table 3 as follows:

[0089] Table 3

[0090] Pressure difference (Pa) Simulated stress value (Pa) Simulated stress value / ultimate stress value 1000 2.40E7 0.18 2000 3.82E7 0.29 3000 5.02E7 0.39 4000 6.09E7 0.47 5000 7.09E7 0.55 6000 8.03E7 0.62 7000 8.92E7 0.67 8000 9.77E7 0.76 9000 1.06E8 0.82 10000 1.14E8 0.88

[0091] The vacuum transition membrane 1 used in the embodiment is safe when the pressure difference is less than 10000 Pa, Figure 3 The vacuum chamber volume on the left side of the vacuum transition membrane 1 is V1=34L and the vacuum chamber volume on the right side of the vacuum transition membrane 1 is V2=134L.

[0092] In the vacuum pumping stage, for the vacuum volume of 134L, the initial pressure is 1E 5 Pa, the inner diameter and length of the two flow conduct elements 10 can be determined as follows:

[0093] When the pressure is 1E-5 Pa, the mean free path is 1E-5 m, the inner diameter is 1E-5 m, the flow is viscous flow, and the inner diameter is 1E-3 m, the pressure The viscous flow condition is met, the pumping speed of the vacuum pump used in this embodiment is When the conductance value of the conductance element 10 connected to one side of the particle beam pipeline 5 with a volume of 134 L , the pumping speed of the particle beam pipeline 5 is mainly determined by .

[0094] When the inner diameter of the conductance element 10 is , , the conductance value of the fixed conductance element 10 under the viscous flow condition can be determined by the following formula:

[0095]

[0096] At this time, taking Figure 3 as an example, the length of the pipeline 102 of the right conductance element 10 in Figure 3 can be obtained , and the length of the pipeline 102 of the conductance element 10 is selected as , which can ensure , the pressure change in the particle beam pipeline 5 on both sides of the vacuum transition membrane 1 over time during the entire vacuum pumping process can be determined by the following formula:

[0097]

[0098] Figure 6 The relationship curve diagram of the pressure change over time in the vacuum pumping stage is schematically shown.

[0099] When the pumping time is 3600 s, the pressure is lower than 10000 Pa.

[0100] In order to ensure the safety of the vacuum transition membrane 1 during the entire pumping process, the pressure difference on both sides is kept at 0 Pa, and the pressure difference on both sides of the vacuum transition membrane 1 can be described by the following formula:

[0101]

[0102] , for , the inner diameter of the pipeline 102 of the left conductance element 10 is selected as Figure 3 , the length of the pipeline 102 of the left conductance element 10 is , at this time, the pressure difference on both sides of the vacuum transition membrane 1 can be theoretically controlled close to 0 Pa.

[0103] The relationship curve diagram of the pressure difference change over time in the vacuum pumping stage is schematically shown. Figure 7

[0104] ​The pressure difference is less than 1000 Pa during the whole vacuum pumping stage.

[0105] The deformation of the vacuum transition membrane 1 is less than 2 mm and the maximum stress value borne by the vacuum transition membrane 1 is less than 3E 7 N / m 2 .

[0106] The initial pressure is about 0 Pa and the external inflation pressure is 1E 5 Pa during the whole atmosphere inflation stage. The length of the flow guide element 10 is 1000 mm. The pressure in the particle beam pipeline 10 on both sides of the vacuum transition membrane 1 can be determined by the following formula during the whole atmosphere inflation stage.

[0107]

[0108] Figure 8 A schematic diagram of the relationship between the pressure and time during the atmosphere inflation stage is shown.

[0109] The pressure is about 100000 Pa when the atmosphere inflation time is 900 s.

[0110] The pressure difference on both sides of the vacuum transition membrane 1 during the whole atmosphere inflation stage can be described by the following formula.

[0111]

[0112] The pipeline 102 inner diameter of the flow guide element 10 is 1000 mm. , At this time, the pressure difference on both sides of the vacuum transition membrane 1 can be theoretically controlled to be close to 0 Pa.

[0113] Figure 9 A schematic diagram of the relationship between the pressure difference and time during the atmosphere inflation stage is shown.

[0114] The pressure difference is less than 1000 Pa during the whole atmosphere inflation stage.

[0115] The deformation of the vacuum transition membrane 1 is less than 2 mm and the maximum stress value borne by the vacuum transition membrane 1 is less than 3E 7 N / m 2 .

[0116] The pressure difference on both sides of the vacuum transition membrane 1 is the vacuum degree of the high-energy transport line during the normal operation process, and the value is less than 1 Pa, so the vacuum transition membrane 1 does not need to consider the action of the gas pressure during the whole operation process.

[0117] The extremely thin vacuum transition device and pressure difference elimination system provided by the present disclosure has good performance after testing and meets the design use requirements.

[0118] It can be understood by those skilled in the art that the features described in various embodiments and / or claims of the present disclosure can be combined or / and integrated in various combinations, even if such combinations or integrations are not explicitly described in the present disclosure. In particular, the features described in various embodiments and / or claims of the present disclosure can be combined and / or integrated in various combinations without departing from the spirit and teachings of the present disclosure. All these combinations and / or integrations fall within the scope of the present disclosure.

[0119] The above describes embodiments of the present disclosure. However, these embodiments are only for illustrative purposes, and are not intended to limit the scope of the present disclosure. Although each embodiment is described above separately, this does not mean that the measures in each embodiment cannot be used advantageously in combination. The scope of the present disclosure is defined by the appended claims and their equivalents. Without departing from the scope of the present disclosure, those skilled in the art can make various substitutions and modifications, which should all fall within the scope of the present disclosure.

Claims

1.A pressure difference elimination system, comprising: an ultra-thin vacuum transition device, comprising: a vacuum transition film configured as a non-metal film with a thickness less than 0.1 millimeter; two sealing connectors respectively arranged on two sides of the vacuum transition film and connected with a particle beam pipeline; the sealing connector comprises: a first flange configured to connect the vacuum transition film and the particle beam pipeline; and a sealing ring arranged between the vacuum transition film and the first flange and configured to seal the vacuum transition film; two particle beam pipelines arranged on two sides of the ultra-thin vacuum transition device and connected with the vacuum transition film through the sealing connectors; a pressure difference elimination device, comprising flow guide assemblies respectively arranged on the two particle beam pipelines and a vacuum pumping assembly, and the two flow guide assemblies and the vacuum pumping assembly are connected through a tee joint; the flow guide assembly comprises: an angle valve comprising two interfaces, one of the two interfaces of the angle valve is connected with the particle beam pipeline, and the other of the two interfaces of the angle valve is connected with a flow guide element; the flow guide element comprises two second flanges and a pipeline connecting the two second flanges, two ends of the pipeline are respectively connected with the two second flanges, one of the two second flanges is connected with the other interface, and the other of the two second flanges is connected with a second bellows; the second bellows comprises two interfaces, one of the two interfaces of the second bellows is connected with the other second flange, and the other of the two interfaces of the second bellows is connected with one of the interfaces of the tee joint; the length of the left flow guide element is equal to 4 times the length of the right flow guide element. 2.The pressure difference elimination system according to claim 1, wherein one of the two particle beam pipelines is connected with the sealing connector through a first bellows. 3.The pressure difference elimination system according to claim 1, wherein the length of the pipeline connecting the two second flanges is related to pressure control requirements in vacuum pumping and air amplification stages; in the case of simultaneous use of the two flow guide elements, the pressure difference elimination system controls the pressure difference on both sides of the vacuum transition film in the process of vacuum pumping and air amplification.

Images