A vacuum detection system for high-precision, large-aperture, and long-focal-length mirrors

Abstract

The present application belongs to the technical field of surface accuracy detection of large-aperture reflectors for optical remote sensors, and particularly relates to a vacuum detection system for high-precision large-aperture and long-focal-length reflectors, comprising: a large-scale vacuum tank, a CGH compensation adjustment mechanism, an interferometer adjustment mechanism, and a large-aperture reflector multi-dimensional adjustment platform; the present application transfers the detection of large-aperture and long-focal-length high-surface-accuracy reflectors to a large vacuum tank, effectively isolating them from external interferences such as airflow and vibration, thereby achieving high-precision surface detection.

Description

Technical Field

[0001] The present application relates to the technical field of surface accuracy detection of large-aperture reflectors for optical remote sensors, and in particular to a vacuum detection system for high-precision large-aperture long-focal-length reflectors. Background Art

[0002] The application of optical remote sensors in fields such as Earth observation and space exploration holds significant scientific and economic significance. The resolution of an optical remote sensor is directly proportional to the aperture of its primary reflector. Therefore, as resolution requirements increase, the aperture also increases. Furthermore, the performance requirements for the reflector also increase, particularly the RMS surface accuracy of the primary reflector. For example, the surface accuracy of a 2-meter-diameter mirror in a large space-based observation system is required to be better than λ / 80 under external load.

[0003] In the development of optical remote sensors, the index satisfaction of the main reflector is a key link in ensuring the overall performance index of the remote sensor. The final performance index of the main reflector assembly depends on its design, processing and testing. All three links are very important, among which testing is the basis for processing and the means of evaluating the final performance, and is crucial. The processing of optical reflectors is divided into multiple processes, and the process of each stage is very different. The process involved in this patent is the fine processing stage, that is, the stage with high accuracy of the surface shape of the later reflector. The detection at this stage is performed by interference detection using an interferometer, because the processing residual at this time is very small, the amount of removal each time cannot be too large, and erroneous removal cannot occur, so there will be more frequent inspections at this stage, and the processing personnel will make corrections at any time according to the test results. The detection accuracy at this time is particularly important. At the same time, this method is used to evaluate the performance of the surface shape of the reflector assembly at the end of the processing.

[0004] For small-diameter reflectors, the small diameter, low surface accuracy requirements (generally, the RMS value is better than λ / 50), and short focal length determine that the surface RMS value is the least sensitive to airflow and vibration interference. Conventional testing environment can meet the requirements, and normal temperature and pressure are sufficient. Conventional normal temperature and pressure testing optical path principle diagram Figure 1 , including: a three-dimensional translation adjustment stage support frame 1, a three-dimensional translation adjustment stage 2, an interferometer 3, a CGH compensator six-dimensional adjustment stage support frame 4, a CGH compensator six-dimensional adjustment stage 5, a CGH compensator assembly 6, a reflector assembly 7, and a reflector multi-dimensional adjustment stage. However, for reflector assemblies with high surface accuracy (surface indicators better than λ / 80), large apertures (over 1.5m), and long focal lengths (over 5m), the surface accuracy is so sensitive to interference from the external environment that it cannot be ignored. Conventional testing environments cannot detect the correct surface shape, making it impossible to guarantee processing and ultimately assess whether the final surface indicators meet the requirements. Summary of the Invention

[0005] In view of this, the present application provides a vacuum detection method for a large-aperture, long-focal-length reflector with high surface accuracy, so as to evaluate the performance index of the large-aperture, long-focal-length reflector with high surface accuracy.

[0006] In order to solve the above technical problems, the present application provides a vacuum detection system for a high-precision large-aperture and long-focal-length reflector, comprising: a large-scale vacuum tank, a CGH compensation adjustment mechanism, an interferometer adjustment mechanism, and a large-aperture reflector multi-dimensional adjustment stage;

[0007] The large-scale vacuum tank is used to carry the detection optical path, and the vacuum degree can reach at least 10 -1 Pa;

[0008] The CGH compensation adjustment mechanism includes a CGH compensator assembly, a CGH compensator six-dimensional adjustment platform, and a CGH compensator six-dimensional adjustment platform support frame.

[0009] The CGH compensator assembly is arranged on the CGH compensator six-dimensional adjustment platform and is used for surface shape compensation of aspheric reflector detection.

[0010] The CGH compensator six-dimensional adjustment stage is arranged on the CGH compensator six-dimensional adjustment stage support frame, and is used to realize the precise fine adjustment of the CGH compensator components in the optical path and complete the interference detection of the optical path. The CGH compensator six-dimensional adjustment stage meets the vacuum use conditions;

[0011] The CGH compensator six-dimensional adjustment platform support frame supports the CGH compensator assembly and the CGH compensator six-dimensional adjustment platform to a theoretical height;

[0012] The interferometer adjustment mechanism includes a small vacuum tank, an interferometer three-dimensional translation adjustment platform, an interferometer three-dimensional translation adjustment platform support frame, a small plane folding mirror assembly, a plane folding mirror adjustment mechanism, a blower air inlet pipe, and a blower air outlet pipe.

[0013] The small vacuum tank is located inside the large-scale vacuum tank and is set on the interferometer three-dimensional adjustment platform. It is used to load the interferometer, computer and its power wires, and is connected to the atmospheric environment through five hoses.

[0014] The interferometer three-dimensional translation adjustment stage is arranged on the interferometer three-dimensional translation adjustment stage support frame, and the upper end is connected to a small vacuum tank. The interferometer three-dimensional translation adjustment stage is used to achieve precise fine-tuning of the interferometer in the optical path. The interferometer three-dimensional translation adjustment stage must meet vacuum use conditions;

[0015] The interferometer three-dimensional translation adjustment stage support frame supports the interferometer and the interferometer three-dimensional translation adjustment stage to a theoretical height;

[0016] The small plane folding mirror assembly is used to fold the detection light path;

[0017] The plane folding mirror adjustment mechanism is used to adjust the small plane folding mirror assembly, to achieve fine position adjustment of the small plane folding mirror assembly, and to ensure self-collimation of the optical path;

[0018] The multi-dimensional adjustment platform for the large-aperture reflector has at least two-dimensional swings of pitch and yaw and horizontal translation perpendicular to the optical axis, and cooperates with the CGH compensator adjustment mechanism and the interferometer adjustment mechanism to achieve interference adjustment of the optical path. The large-aperture reflector is mostly an adjustment platform that needs to meet vacuum conditions;

[0019] The blower air inlet pipe and the blower air outlet pipe are air cooling channels for cooling the small vacuum tank.

[0020] Furthermore, the large-scale vacuum tank includes: a large-scale vacuum tank end cover, a large-scale vacuum tank body, a first load-bearing aluminum plate, a hollow load-bearing platform, and a second load-bearing aluminum plate.

[0021] The first bearing aluminum plate is fixed on the hollow bearing platform to support the reflector assembly and the reflector assembly multi-dimensional adjustment platform; the second bearing aluminum plate is fixed on the hollow bearing platform to support the small vacuum tank, the interferometer three-dimensional translation adjustment platform bracket, the interferometer three-dimensional translation adjustment platform, the CGH compensator six-dimensional adjustment platform support frame, the CGH compensator six-dimensional adjustment platform, and the CGH compensator assembly.

[0022] Furthermore, the large-scale vacuum tank is of side-opening type, and the bottom of the hollow bearing platform is provided with rollers, which can slide along the bearing guide rail at the bottom of the large-scale vacuum tank body. The shock absorption system of the bearing guide rail is directly connected to the foundation and passes through the bottom of the large-scale vacuum tank.

[0023] Furthermore, the small vacuum tank is designed with a window glass to ensure that the light emitted by the interferometer can be irradiated onto the primary mirror and then reflected to form an interference image.

[0024] Furthermore, the small plane folding mirror assembly and the plane folding mirror adjustment mechanism are used in combination to fold the light path. When the light path is long and exceeds the length of a large-scale vacuum tank, it can be used to fold the light path to shorten the length of the light path.

[0025] Furthermore, the interior of the small vacuum tank is provided with an air cooling system, and the air cooling system is distributed on the side walls of the small vacuum tank.

[0026] Furthermore, it also includes a wire carrying tube for carrying the data line and power line of the interferometer and the temperature sensor wire. The temperature sensor enters the small vacuum tank from the wire carrying tube carrying the temperature sensor to display the temperature inside the small vacuum tank in real time.

[0027] Furthermore, the blower air inlet pipe, the blower air outlet pipe and the wire carrying pipe respectively connect the interior of the small vacuum tank with the external normal pressure environment through the rear end interface of the small vacuum tank and the first vacuum flange, the second vacuum flange and the third vacuum flange.

[0028] Furthermore, the first vacuum flange, the second vacuum flange, and the third vacuum flange are installed on the outer wall of the large-scale vacuum tank to isolate the vacuum environment inside the large-scale vacuum tank from the external normal pressure environment.

[0029] Furthermore, the blower air inlet pipe, the blower air outlet pipe, and the wire carrying tube are all composed of two parts, one part is a rubber hose and the other part is a metal bellows. The combination of the two can effectively absorb the micro-vibration on the large-scale vacuum tank body while ensuring the connection length.

[0030] Compared with the existing technology, the beneficial effect of the present application is that: the present application utilizes the vacuum environment of a large-scale vacuum tank and places the entire detection optical path of the reflector in a vacuum vibration isolation environment, so that the detection of high-precision large-aperture and long-focal-length reflectors can avoid interference from external environments such as vibration and airflow, thereby realizing effective detection of high-precision surface indicators. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0032] Figure 1 This is the principle diagram of traditional reflector surface shape detection;

[0033] Figure 2 A schematic diagram of the structure of a vacuum detection system provided in an embodiment of the present application;

[0034] Figure 3 A schematic diagram of the structure of a large-scale vacuum tank provided in an embodiment of the present application;

[0035] Figure 4 This is a schematic diagram of the structure of a small vacuum tank provided in an embodiment of the present application.

[0036] Description of reference numerals:

[0037] Traditional structure: 1. 3D translation adjustment stage support frame; 2. 3D translation adjustment stage; 3. Interferometer; 4. CGH compensator 6D adjustment stage support frame; 5. CGH compensator 6D adjustment stage; 6. CGH compensator assembly; 7. Reflector assembly; 8. Reflector multi-dimensional adjustment stage;

[0038] The present application structure includes: 9. Plane folding mirror mechanism; 10. Small plane folding mirror assembly; 11. Interferometer power line carrier tube; 12. Interferometer data line carrier tube; 13. First vacuum flange; 14. Second vacuum flange; 15. Large-scale vacuum tank; 16. Reflector assembly; 17. Reflector assembly multi-dimensional adjustment platform; 18. CGH compensator assembly; 19. CGH compensator six-dimensional adjustment platform; 20. CGH compensator six-dimensional adjustment platform support frame; 21. Third vacuum flange; 22. Interferometer three-dimensional translation adjustment platform bracket; 23. Temperature sensor wire carrier tube; 24. Interferometer three-dimensional translation adjustment platform; 25. Small vacuum tank; 26. Blower air inlet pipe; 27. Blower air outlet pipe;

[0039] 151. Large-size vacuum tank end cover; 152. Large-size vacuum tank body; 153. First load-bearing aluminum plate; 154. Hollow load-bearing platform; 155. Second load-bearing aluminum plate;

[0040] 251. Small vacuum tank body; 252. Computer host; 253. Small vacuum tank gland; 254. Small vacuum tank gland fastening bolts; 255. U-shaped air inlet pipe inside the small vacuum tank; 256. Interferometer; 257. Gland sealing ring; 258. Window glass; 259. U-shaped air outlet pipe inside the small vacuum tank. DETAILED DESCRIPTION

[0041] To make the purpose, technical solutions and advantages of this application more clear, the technical solutions of this application will be described clearly and completely below in conjunction with the specific embodiments of this application and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of this application, not all of them.

[0042] The present application is used to realize vacuum testing of high-precision large-aperture long-focal-length reflective mirrors. The main structure of the vacuum testing system of the high-precision large-aperture long-focal-length reflective mirror is as follows: Figure 2As shown, it includes a plane folding mirror mechanism 9, a small plane folding mirror assembly 10, an interferometer power line carrying tube 11, an interferometer data line carrying tube 12, a first vacuum flange 13, a second vacuum flange 14, a large-scale vacuum tank 15, a reflector assembly 16, a reflector assembly multi-dimensional adjustment stage 17, a CGH compensator assembly 18, a CGH compensator six-dimensional adjustment stage 19, a CGH compensator six-dimensional adjustment stage support 20, a third vacuum flange 21, an interferometer three-dimensional translation adjustment stage bracket 22, a temperature sensor wire carrying tube 23, an interferometer three-dimensional translation adjustment stage 24, a small vacuum tank 25, a blower air inlet pipe 26, and a blower air outlet pipe 27. Among them, the large-scale vacuum tank 15 is the carrier of the entire detection optical path, and the plane folding mirror mechanism 9, the reflector assembly multi-dimensional adjustment stage 17, the CGH compensator six-dimensional adjustment stage 19, and the interferometer three-dimensional translation adjustment stage 24 all meet vacuum conditions.

[0043] Specifically, the large-scale vacuum tank 15 includes a large-scale vacuum tank end cap 151, a large-scale vacuum tank body 152, a first aluminum support plate 153, a hollow support platform 154, and a second aluminum support plate 155. The first aluminum support plate is fixed to the hollow support platform 154 and supports the reflector assembly 16 and the reflector assembly multi-dimensional adjustment stage 17. The second aluminum support plate 155 is fixed to the hollow support platform 154 and supports the small vacuum tank 25, the interferometer three-dimensional translation adjustment stage bracket 22, the interferometer three-dimensional translation adjustment stage 24, the CGH compensator six-dimensional adjustment stage support frame 20, the CGH compensator six-dimensional adjustment stage 19, and the CGH compensator assembly 18. All hardware for the detection optical path is placed on the hollow support platform 154. The hollow support platform 154 has rollers at its bottom that can slide along the guide rails at the bottom of the large-scale vacuum tank body 152. The vibration damping system of the support rails is directly connected to the foundation, perfectly isolating the hollow support platform 154 from ground vibrations.

[0044] Specifically, the small vacuum tank 25 comprises a small vacuum tank body 251, a computer host 252, a small vacuum tank gland 253, gland fastening bolts 254, a U-shaped air inlet duct 255 inside the small vacuum tank, an interferometer 256, a gland seal 257, a window glass 258, and a U-shaped air outlet duct 259 inside the small vacuum tank. The small vacuum tank 25 has a gland-type structure with multiple bolt connections at the top, and ample internal space for the interferometer 256 and computer case 252. The small vacuum tank has a window glass at the front and a rear end with interfaces for a wire-carrying tube and the blower inlet and outlet ducts.

[0045] Computer case 252 and interferometer 256 are placed within small vacuum tank body 251. Small vacuum tank gland 253 is connected to the interior of small vacuum tank body 251 via multiple bolts 254. A gland seal 254 is placed between gland 253 and body 251 to ensure the sealing performance of small vacuum tank 25. The outer end of U-shaped air inlet duct 255 inside the small vacuum tank is connected to the blower air inlet duct 26. U-shaped air inlet duct 255 is arranged on the side wall of small vacuum tank body 251 in a U-shaped pattern with uniform holes, ensuring that cooling air entering from blower air inlet duct 26 is evenly blown into the tank. U-shaped air outlet duct 259 is located on the other side wall of small vacuum tank body 251 and has the same structure as U-shaped air inlet duct 255. High-temperature air from the tank flows evenly out through the holes in U-shaped air outlet duct 259, achieving the purpose of cooling the interior of small vacuum tank 25. The temperature sensor enters the tank through the temperature sensor wire carrying tube 23 and displays the temperature inside the tank in real time. Excessive temperature will cause the interferometer to malfunction. The spherical wave emitted by the interferometer passes through the window glass 258 into the interior of the vacuum tank to form an interference detection optical path. The diameter of the window glass 258 is less than 80 mm, and its projected wavefront error shall not exceed λ / 80.

[0046] The specific implementation process of the vacuum test system for high-precision large-aperture and long-focal-length mirrors is shown in the following table. Figure 2 、 3 、4.

[0047] First, open the end cover 151 of the large-scale vacuum tank, slide the hollow bearing platform 154 out along the guide rail at the bottom of the large-scale vacuum tank body 152, and use the external movable guide rail to fix the first bearing aluminum plate 153 on the hollow bearing platform 154. Install the supporting mirror assembly 16 and the multi-dimensional adjustment platform 17 of the mirror assembly on the first bearing aluminum plate 153 according to theory, and fix the second bearing aluminum plate 155 on the hollow bearing platform 154. Install the small vacuum tank 25, the interferometer three-dimensional translation adjustment platform bracket 22, the interferometer three-dimensional translation adjustment platform 24, the CGH compensator six-dimensional adjustment platform support frame 20, the CGH compensator six-dimensional adjustment platform 19, and the CGH compensator assembly 18 on the second bearing aluminum plate 155 according to the theoretical position, and fix each component with screws and blocks.

[0048] Then, slide the hollow bearing platform 154 into the interior of the large-scale vacuum tank body 15 along the guide rail at the bottom of the large-scale vacuum tank body 152, and fasten the hollow bearing platform 154 to the guide rail at the bottom of the large-scale vacuum tank body 152. Connect the power cord and data cable of the multi-dimensional adjustment stage 17 of the reflector assembly to one side of the vacuum chamber of the second vacuum flange 14, and connect the other side to a normal temperature and normal pressure power supply and data acquisition equipment. Connect the power cord and data cable of the interferometer three-dimensional translation adjustment stage bracket 22 and the CGH compensator six-dimensional adjustment stage 19 to one side of the vacuum chamber of the third vacuum flange 21, respectively, and connect the other side to a normal temperature and normal pressure power supply and data acquisition equipment. Seal the blower air inlet pipe 26 and the blower air outlet pipe 27 to the small vacuum tank 25, and seal the other end to the first vacuum flange 13 to achieve temperature control inside the vacuum tank. The temperature sensor wire carrier tube 23 is sealed to the small vacuum tank 25. Its other end is sealed to the third vacuum flange 21. It carries the temperature sensor wires inside and displays the temperature inside the small vacuum tank in real time, ensuring that the interferometer always operates within the appropriate temperature range. The interferometer power cable carrier tube 11 is sealed to the small vacuum tank 25. Its other end is sealed to the second vacuum flange 14. It carries the data cable between the interferometer 256 and the computer host 252, which is connected to the external data acquisition computer. The interferometer data cable carrier tube 12 is sealed to the small vacuum tank 25. Its other end is sealed to the second vacuum flange 14. It carries the power cables between the interferometer 256 and the computer host 252.

[0049] After the above-mentioned data lines are connected, power is turned on and the vibration isolation system (air flotation) at the bottom of the large-scale vacuum tank body 152 is turned on. After the vibration isolation system works, coupled with the vibration isolation of the rubber tube + bellows, the entire detection optical path is no longer disturbed by vibration. Adjust the interference optical path until interference fringes appear. There is no need to adjust to the zero-order fringes. Just complete the rough adjustment.

[0050] Then, close the large-scale vacuum tank end cover 151 and the large-scale vacuum tank body 152, and start evacuating the large-scale vacuum tank 15 until the vacuum degree reaches 10 -1 Pa, at this time the entire interference light path is no longer affected by the airflow, and the interference light path is fine-tuned according to the interference pattern of the external acquisition computer until zero-order fringes appear. The detection result at this time is the true surface accuracy of the reflector, which is used to guide the processing of the reflector surface and complete the evaluation of the final surface accuracy.

[0051] The vacuum detection system in this application transfers a conventional detection system to a vacuum vibration isolation environment. Using a small vacuum tank with window glass, air inlet and outlet ducts, and a wire-carrying tube, the interferometer, which cannot operate in a vacuum environment, is cleverly transferred to normal temperature and pressure. The system also utilizes the vibration isolation function of the large-scale vacuum tank and the vibration absorption function of the rubber + bellows combination pipe. By utilizing the vacuum environment of the large-scale vacuum tank, the entire detection optical path of the reflector is placed in a vacuum vibration isolation environment. This allows the detection of high-precision, large-aperture, long-focal-length reflectors to avoid interference from external environments such as vibration and airflow, thereby achieving effective detection of high-precision surface indicators.

[0052] The foregoing is merely an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included within the scope of the claims of the present application.

Claims

1. A vacuum detection system for a high-precision, large-aperture, long-focal-length reflector, characterized in that: include: Large-scale vacuum tank, CGH compensation adjustment mechanism, interferometer adjustment mechanism, large-aperture mirror multi-dimensional adjustment stage; The large-scale vacuum tank is used to carry the detection optical path, and the vacuum degree reaches at least 10 -1 Pa; The CGH compensation adjustment mechanism includes a CGH compensator assembly, a CGH compensator six-dimensional adjustment platform, and a CGH compensator six-dimensional adjustment platform support frame. The CGH compensator assembly is arranged on the CGH compensator six-dimensional adjustment platform and is used for surface shape compensation of aspheric reflector detection. The CGH compensator six-dimensional adjustment stage is arranged on the CGH compensator six-dimensional adjustment stage support frame, and is used to realize the precise fine adjustment of the CGH compensator components in the optical path and complete the interference detection of the optical path. The CGH compensator six-dimensional adjustment stage meets the vacuum use conditions; The CGH compensator six-dimensional adjustment platform support frame supports the CGH compensator assembly and the CGH compensator six-dimensional adjustment platform to a theoretical height; The interferometer adjustment mechanism includes a small vacuum tank, an interferometer three-dimensional translation adjustment platform, an interferometer three-dimensional translation adjustment platform support frame, a small plane folding mirror assembly, a plane folding mirror adjustment mechanism, a blower air inlet pipe, and a blower air outlet pipe. The small vacuum tank is located inside the large-scale vacuum tank and is set on the interferometer three-dimensional adjustment platform. It is used to load the interferometer, computer and its power wires, and is connected to the atmospheric environment through five hoses. The interferometer three-dimensional translation adjustment stage is arranged on the interferometer three-dimensional translation adjustment stage support frame, and the upper end is connected to a small vacuum tank. The interferometer three-dimensional translation adjustment stage is used to achieve precise fine-tuning of the interferometer in the optical path. The interferometer three-dimensional translation adjustment stage must meet vacuum use conditions; The interferometer three-dimensional translation adjustment stage support frame supports the interferometer and the interferometer three-dimensional translation adjustment stage to a theoretical height; The small plane folding mirror assembly is used to fold the detection light path; The plane folding mirror adjustment mechanism is used to adjust the small plane folding mirror assembly, to achieve fine position adjustment of the small plane folding mirror assembly, and to ensure self-collimation of the optical path; The multi-dimensional adjustment platform for the large-aperture reflector has at least two-dimensional swings of pitch and yaw and horizontal translation perpendicular to the optical axis, and cooperates with the CGH compensation adjustment mechanism and the interferometer adjustment mechanism to achieve interference adjustment of the optical path. The large-aperture reflector is mostly an adjustment platform that needs to meet vacuum conditions; The blower air inlet pipe and the blower air outlet pipe are air cooling channels for cooling the small vacuum tank.

2. A vacuum detection system for a high-precision, large-aperture, long-focal-length reflector according to claim 1, characterized in that: The large-scale vacuum tank includes: a large-scale vacuum tank end cover, a large-scale vacuum tank body, a first load-bearing aluminum plate, a hollow load-bearing platform, and a second load-bearing aluminum plate. The first bearing aluminum plate is fixed on the hollow bearing platform to support the reflector assembly and the reflector assembly multi-dimensional adjustment platform; the second bearing aluminum plate is fixed on the hollow bearing platform to support the small vacuum tank, the interferometer three-dimensional translation adjustment platform bracket, the interferometer three-dimensional translation adjustment platform, the CGH compensator six-dimensional adjustment platform support frame, the CGH compensator six-dimensional adjustment platform, and the CGH compensator assembly.

3. A vacuum detection system for a high-precision, large-aperture, long-focal-length reflector according to claim 2, characterized in that: The large-scale vacuum tank is of the side-opening type, and the bottom of the hollow bearing platform is provided with rollers, which slide along the bearing guide rails at the bottom of the large-scale vacuum tank body. The shock absorption system of the bearing guide rails is directly connected to the foundation and passes through the bottom of the large-scale vacuum tank.

4. A vacuum detection system for a high-precision, large-aperture, long-focal-length reflector according to claim 1, characterized in that: The small vacuum tank is designed with a window glass to ensure that the light emitted by the interferometer is irradiated onto the primary mirror and then reflected to form an interference image.

5. The vacuum detection system for a high-precision, large-aperture, long-focal-length reflector according to claim 1, characterized in that: The small plane folding mirror assembly and the plane folding mirror adjustment mechanism are used in conjunction with each other to fold the light path. When the light path is longer than the length of the large-scale vacuum tank, the light path is folded to shorten the length of the light path.

6. The vacuum detection system for a high-precision, large-aperture, long-focal-length reflector according to claim 1, characterized in that: The interior of the small vacuum tank is provided with an air cooling system, and the air cooling system is distributed on the side walls of the small vacuum tank.

7. The vacuum detection system for a high-precision, large-aperture, long-focal-length reflector according to claim 1, characterized in that: It also includes a wire carrying tube for carrying the data line and power line of the interferometer and the temperature sensor wire. The temperature sensor enters the small vacuum tank from the wire carrying tube carrying the temperature sensor to display the temperature in the small vacuum tank in real time.

8. The vacuum detection system for a high-precision, large-aperture, long-focal-length reflector according to claim 7, characterized in that: The blower air inlet pipe, the blower air outlet pipe and the wire carrying pipe respectively connect the interior of the small vacuum tank with the external normal pressure environment through the rear end interface of the small vacuum tank and the first vacuum flange, the second vacuum flange and the third vacuum flange.

9. The vacuum detection system for a high-precision, large-aperture, long-focal-length reflector according to claim 8, characterized in that: The first vacuum flange, the second vacuum flange, and the third vacuum flange are installed on the outer wall of the large-scale vacuum tank to isolate the vacuum environment inside the large-scale vacuum tank from the external normal pressure environment.

10. The vacuum detection system for a high-precision, large-aperture, long-focal-length reflector according to claim 7, characterized in that: The blower air inlet pipe, the blower air outlet pipe, and the wire carrying pipe are all composed of two parts, one part is a rubber hose and the other part is a metal bellows. The two work together to effectively absorb the micro-vibration on the large-scale vacuum tank body while ensuring the connection length.

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