A special-shaped vacuum differential structure

Abstract

The present invention relates to a special-shaped vacuum differential structure, comprising: a first-stage micro-conical differential tube and a second-stage micro-conical differential tube, with a first-stage expansion differential chamber welded between them; the microporous structures within the first-stage micro-conical differential tube and the microporous structures within the second-stage micro-conical differential tube both exhibiting a conical structure; the volume within the first-stage expansion differential chamber exhibiting an expansion structure; the downstream end of the second-stage micro-conical differential tube being welded to the upper end face of the second-stage differential chamber; and the internal openings of the first-stage micro-conical differential tube, the upstream and downstream end face openings of the first-stage expansion differential chamber, the internal openings of the second-stage micro-conical differential tube, and the upper end face opening of the second-stage differential chamber all being concentric. The present invention can achieve multiple vacuum degree transitions within a limited space and a relatively short differential axial distance, and ensure the collimation accuracy and margin requirements of synchronous light in the vacuum differential structure.

Description

Technical Field

[0001] The present invention relates to the field of vacuum, and in particular to a special-shaped vacuum differential structure. Background Art

[0002] In the field of synchrotron radiation, the synchrotron light obtained by the experimental station is generated by the accelerator, passes through the transmission pipeline, and finally reaches the experimental terminal. Because the vacuum requirements of each unit in the beamline vary, some cases require the use of a differential structure and a suitable vacuum pump set to achieve a vacuum pressure gradient transition.

[0003] In the design of vacuum differential structure, it is necessary to ensure that the synchronization light can pass through the differential structure smoothly. Sometimes the synchronization light spot size is in the micron level. Figure 1 ), especially the straight-through tube with multi-level differential structure can achieve high vacuum differential, but it is difficult to meet the beam collimation accuracy and collimation margin requirements of the synchronization light in a small aperture.

[0004] Secondly, the space and effective axial length reserved for the differential structure in physical design are very limited in many cases. Within the limited space and limited axial distance, it is necessary to comprehensively consider the space requirements that must be met by the differential pipeline, differential cavity and necessary vacuum equipment. In conventional vacuum differential design (such as Figure 1 , as shown in Figure 2), the differential chamber typically uses a cylindrical chamber to match the vacuum equipment for pumping. The size of the differential chamber has a direct impact on the vacuum level achieved by the entire differential structure. However, when the size of the differential chamber is limited by the space of the entire differential structure and the axial distance of the differential structure, the vacuum differential effect that can be achieved is also limited to a certain extent.

[0005] In summary, how to achieve multiple orders of magnitude transition of vacuum from low vacuum to ultra-high vacuum within the limited physical design space and the limited differential axial distance, and how to ensure the collimation accuracy requirements of the differential structure for micron-level light beams are technical challenges that urgently need to be solved. Summary of the Invention

[0006] The present invention provides a special-shaped vacuum differential structure, which can realize multiple orders of magnitude transition of vacuum degree within a limited space and a short differential axial distance, and ensure the collimation accuracy and margin requirements of synchronization light in the vacuum differential structure.

[0007] In order to achieve the above-mentioned purpose, the technical solution of the present invention is: a special-shaped vacuum differential structure, comprising a first-level micro-conical structure differential tube, a first-level expansion structure differential chamber, a second-level micro-conical structure differential tube, and a second-level differential chamber, a first-level expansion structure differential chamber is welded between the first-level micro-conical structure differential tube and the second-level micro-conical structure differential tube, the microporous structure inside the first-level micro-conical structure differential tube and the microporous structure inside the second-level micro-conical structure differential tube both present a conical structure, the volume inside the first-level expansion structure differential chamber presents an expansion structure, the downstream end of the second-level micro-conical structure differential tube is welded to the upper end face of the second-level differential chamber, and the first-level micro-conical structure differential tube has an internal opening, the second-level micro-conical structure differential tube has an internal opening, the first-level expansion structure differential chamber has an upstream and downstream end face opening, and the second-level differential chamber has an upper end face opening that is all on concentric circles.

[0008] Furthermore, the microporous structures inside the primary micro-conical structure differential tube and the secondary micro-conical structure differential tube have a certain aperture angle α expansion structure from the upstream end to the downstream end of the differential tube.

[0009] Furthermore, a secondary differential connecting flange is welded to the downstream end of the secondary differential chamber.

[0010] Furthermore, vacuum pump flanges are welded to the two exhaust ports of the differential chamber of the first-stage expansion structure and the two exhaust ports of the differential chamber of the second-stage expansion structure, respectively.

[0011] Furthermore, a matching molecular pump and a corresponding ion pump are respectively installed on the two vacuum pump flanges of the first-level differential chamber.

[0012] Furthermore, corresponding ion pumps and corresponding getter pumps are respectively installed on the two vacuum pump flanges of the secondary differential chamber.

[0013] The beneficial effects of the present invention are:

[0014] In order to achieve a higher order of vacuum transition, a two-stage differential structure is adopted. By welding the downstream end of the differential chamber of the first-stage expansion structure and the upstream end of the differential tube of the second-stage micro-conical structure, the volume in the differential chamber of the first-stage expansion structure presents the characteristics of the expansion structure, so that the volume of the differential chamber of the differential structure is maximized within an extremely short axial distance, thereby better improving the vacuum effect after the first-stage differential. At the same time, from the perspective of particle trajectory tracking, the use of an expansion structure can also avoid and limit a large number of gas molecules from entering the second-stage differential structure, so that a higher vacuum degree can be achieved after the second-stage differential. At the same time, the second-stage micro-conical structure differential tube and the second-stage differential chamber are welded, so that the vacuum pump can promptly remove the gas molecules in the second-stage differential chamber, thereby obtaining a higher vacuum degree.

[0015] By welding the secondary differential chamber and the secondary differential connecting flange, the experimental terminal can smoothly obtain a high vacuum environment, thereby maintaining the intensity of the synchronous light and enabling scientific experiments to achieve better results.

[0016] In the entire differential structure, from the inlet end of the first-level differential pipe to the outlet end of the second-level differential pipe, a micro-conical structure is used throughout the entire differential structure, and it is ensured that the micro-conical structure maintains a specific opening angle in the entire differential structure.

[0017] Through the present invention, that is, within a limited space and axial distance, through the design of a micro-conical differential pipeline and an expansion structure differential cavity, the transition from multiple orders of magnitude from vacuum to ultra-high vacuum is solved, and the technical difficulties of the collimation accuracy and margin required by the synchrotron light in the micro-pore differential structure in synchrotron radiation are also solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a three-dimensional schematic diagram of a conventional differential structure;

[0019] Figure 2 It is a cross-sectional view of a conventional differential structure;

[0020] Figure 3 It is the overall diagram of the differential structure of the special-shaped structure of the present invention;

[0021] Figure 4 is a cross-sectional view of the differential structure of the special-shaped structure of the present invention;

[0022] Figure 5 Schematic diagram of the micro-conical hole structure in the differential structure of the present invention;

[0023] Figure 6 is a schematic diagram of the expansion structure cavity in the differential structure of the present invention;

[0024] Figure 7 This is a graph of the ultra-high vacuum pressure that can be achieved by the differential structure in a 1E-5mbar vacuum environment. DETAILED DESCRIPTION

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0026] like Figure 3 As shown in Figure 4, the special-shaped vacuum differential structure of the present invention includes a first-level differential connecting flange 11, a first-level micro-conical structure differential tube 12, a first-level expansion structure differential chamber 15, two first-level differential chamber vacuum pump flanges 1, 13 and 14, a second-level micro-conical structure differential tube 21, a second-level differential chamber 24 and the second-level differential chamber vacuum pump flanges 1, 22 and 23 and a second-level differential connecting flange 25.

[0027] All components must meet machining accuracy requirements and undergo ultra-high vacuum cleaning. Assembly and welding must be performed according to the design, maintaining a welding accuracy of ±0.1mm or less. Slag inclusions and air holes must be avoided, as these negatively impact the equipment's ultimate vacuum level. Furthermore, the machining tolerance of the tapered bore within the differential piping must be within ±10 microns.

[0028] Weld the primary differential connection flange 11 to the upstream end of the primary micro-conical structure differential pipe 12 (such as Figure 3 , 4), the end face of the first differential connection flange 11 is at 90 degrees to the first micro-conical structure differential tube 12. The microporous structure inside the first micro-conical structure differential tube 12 has a certain opening angle α expansion structure from the upstream end to the downstream end of the differential tube, and the overall structure is a tapered structure (as shown in FIG. Figure 5 As shown in the figure, A is the center line of the tapered hole, B is the micro-tapered hole structure of the first-level micro-tapered structure differential tube, and C is the micro-tapered hole structure of the second-level micro-tapered structure differential tube). The inner hole of the differential tube is a tapered structure, which is mainly to ensure that the collimation accuracy requirements of the synchronous light are met.

[0029] The downstream end of the first-stage micro-conical structure differential tube 12 and the upstream end of the first-stage expansion structure differential chamber 15 are welded to ensure that they are absolutely perpendicular to each other and that the internal opening of the first-stage micro-conical structure differential tube 12 and the upstream end opening of the first-stage expansion structure differential chamber 15 are on the same concentric circle. Figure 3 , as shown in 4).

[0030] The volume inside the differential chamber of the primary expansion structure presents an expansion structure (e.g. Figure 6 As shown, D is the first-level differential tube micro-conical hole, E is the first-level differential expansion cavity, F is the second-level differential tube micro-conical hole, and G is the second-level differential expansion cavity).

[0031] The upstream end of the secondary micro-conical structure differential tube 21 and the downstream end of the primary expansion structure differential chamber 15 are welded so that they are absolutely perpendicular to each other, and ensure that the internal opening of the secondary micro-conical structure differential tube 21 and the downstream end opening of the primary expansion structure differential chamber 15 are on concentric circles.

[0032] The downstream end of the secondary micro-conical differential tube 21 is welded to the upper end of the secondary differential chamber 24, ensuring they are absolutely perpendicular and that the internal opening of the secondary micro-conical differential tube 21 and the upper end opening of the secondary differential chamber 24 are concentric. Finally, the secondary differential connection flange 25 is welded to the downstream end of the secondary differential chamber 24. By welding the secondary differential chamber 24 and the secondary differential connection flange 25, the experimental terminal can smoothly achieve a high vacuum environment, thereby maintaining the intensity of the synchrotron light and achieving better results in scientific experiments.

[0033] At this point, the main structure of the differential structure is welded and it is necessary to ensure that the internal openings from the upstream end of the first differential to the downstream end of the second differential are on the same concentric circle.

[0034] The two exhaust ports of the first-stage expansion structure differential chamber 15 are welded with the vacuum pump flanges one, two 13 and 14 of the first-stage differential chamber. At the same time, the two exhaust ports of the second-stage differential chamber 24 are also welded with the vacuum pump flanges one, two 22 and 23 of the second-stage differential chamber.

[0035] The present invention solves the problem of multiple levels of transition from high vacuum to ultra-high vacuum (such as Figure 7 As shown in the figure), it also solves the technical problems of the collimation accuracy and margin required by synchrotron light in the micro-hole differential structure in synchrotron radiation (as shown in the figure). Figure 5 shown).

[0036] After the differential structure is formed, a matching molecular pump is installed on the vacuum pump flange 13 of the first differential chamber, and a corresponding ion pump is installed on the vacuum pump flange 14 of the first differential chamber, according to the requirements of the first differential. According to the requirements of the second differential, a corresponding ion pump is installed on the vacuum pump flange 1 22 of the second differential chamber, and a corresponding getter pump is configured on the vacuum pump flange 2 23 of the second differential chamber.

Claims

1. A special-shaped vacuum differential structure, characterized by: It includes a first-level micro-conical structure differential tube, a first-level expansion structure differential chamber, a second-level micro-conical structure differential tube, and a second-level differential chamber. The first-level expansion structure differential chamber is welded between the first-level micro-conical structure differential tube and the second-level micro-conical structure differential tube. The microporous structure inside the first-level micro-conical structure differential tube and the microporous structure inside the second-level micro-conical structure differential tube both present a conical structure. The volume inside the first-level expansion structure differential chamber presents an expansion structure. The downstream end of the second-level micro-conical structure differential tube is welded to the upper end face of the second-level differential chamber, and it is ensured that the opening inside the first-level micro-conical structure differential tube, the openings on the upstream and downstream end faces of the first-level expansion structure differential chamber, the openings inside the second-level micro-conical structure differential tube, and the openings on the upper end face of the second-level differential chamber are all on concentric circles.

2. The special-shaped vacuum differential structure according to claim 1, characterized in that: The microporous structures inside the primary micro-conical structure differential tube and the secondary micro-conical structure differential tube have a certain aperture angle α expansion structure from the upstream end to the downstream end of the differential tube.

3. The special-shaped vacuum differential structure according to claim 1, characterized in that: A secondary differential connecting flange is welded to the downstream end of the secondary differential chamber.

4. The special-shaped vacuum differential structure according to claim 1, characterized in that Vacuum pump flanges are respectively welded to the two exhaust ports of the differential chamber of the first-stage expansion structure and the two exhaust ports of the differential chamber of the second-stage expansion structure.

5. The special-shaped vacuum differential structure according to claim 4, characterized in that A matching molecular pump and a corresponding ion pump are respectively installed on the two vacuum pump flanges of the first-level differential chamber.

6. The special-shaped vacuum differential structure according to claim 4, characterized in that The two vacuum pump flanges of the secondary differential chamber are respectively equipped with corresponding ion pumps and corresponding getter pumps.

Images