CN110398834B

CN110398834B - Sealed inflatable solar telescope of ground

Info

Publication number: CN110398834B
Application number: CN201910608506.3A
Authority: CN
Inventors: 饶长辉; 刘洋毅; 顾乃庭; 王成; 饶学军; 李程
Original assignee: Institute of Optics and Electronics of CAS
Current assignee: Institute of Optics and Electronics of CAS
Priority date: 2019-07-08
Filing date: 2019-07-08
Publication date: 2021-03-23
Anticipated expiration: 2039-07-08
Also published as: CN110398834A

Abstract

The invention provides a ground-based sealed inflatable solar telescope which comprises main sealing window glass (1), a lens cone inflation inlet (2), a lens cone (3), a heat diaphragm liquid inlet pipe (4-1), a main mirror (5), a four-way joint (6), an air distribution box (7), an air inlet pipe (8-1), a main mirror rear cover (9), a sealed heat insulation layer (10), a lens cone exhaust port (11), a heat diaphragm liquid outlet pipe (4-2), a heat diaphragm (12), a gas state monitoring module (13) and a secondary mirror (14). The invention adopts the closed lens cone, thus effectively protecting the optical device; the inert gas is filled, so that the pressure difference between the inside and the outside of the lens barrel is obviously reduced; thermal control minimizes specular thermal distortion and local seeing effects. The invention has the advantages of effective protection of optical devices, no obvious pressure difference inside and outside the lens cone, no obvious thermal effect, easy maintenance and the like, is obviously superior to the scheme of the existing solar telescope, and has strong innovation and practicability.

Description

Sealed inflatable solar telescope of ground

Technical Field

The invention relates to the field of astronomical observation instruments and equipment, in particular to a foundation sealing inflatable solar telescope.

Background

The solar imaging observation data is the most basic observation data for solar physical research and solar activity forecast, and the most important equipment for acquiring the solar imaging observation data is a foundation solar telescope. According to the diffraction limit formula, a larger aperture of the optical system will bring higher resolution. Therefore, in order to acquire smaller-scale solar activity information, the caliber of the ground-based solar telescope is increasing.

Before 2000, the aperture of the solar telescope is more than 1 meter. In order to protect optical elements, the telescope adopts a closed structure mostly, and meanwhile, in order to further eliminate mirror surface thermal deformation and local seeing effect caused by overheating of optical devices, the lens barrel is vacuumized, so that the vacuum type solar telescope is formed. In 2000, the caliber of the solar telescope breaks through the meter level till now, and the meter level reaches 2 meters and 4 meters in sequence. Due to the difficulty in manufacturing large-aperture window-sealing glass and the influence of pressure birefringence effect, the ground-based large-aperture solar telescope gradually abandons the vacuum design, and starts to adopt an open design, namely all optical devices are exposed in the environment, and meanwhile, the thermal control is performed on devices such as a thermal diaphragm, a primary mirror and the like so as to reduce the mirror surface thermal deformation and the local seeing effect.

However, both vacuum solar telescopes and open solar telescopes have some drawbacks that are difficult to overcome.

The vacuum type solar telescope lens barrel requires extremely high vacuum degree in a closed space, so that high requirements are provided for the air tightness of a telescope structure, the sealing level is limited, the telescope needs to be regularly pumped to maintain the high vacuum degree in the lens barrel (generally, pumping maintenance is needed every 1-2 weeks), and the maintenance and operation cost of the telescope is increased; because the pressure difference of near atmosphere exists inside and outside the telescope, larger pressure is formed on the telescope structure, which is not beneficial to the stability of the telescope structure; although the higher vacuum degree in the lens cone fundamentally eliminates the local seeing effect, the main mirror is directly irradiated without effective thermal control, and the larger mirror surface thermal deformation exists, so that the imaging performance of the system is influenced; in addition, because the large-caliber window sealing glass is difficult to manufacture, the application of the vacuum type solar telescope in a solar telescope with a larger caliber above a meter level is fundamentally limited.

All optical devices in the open-type solar telescope are directly exposed in the environment and directly influenced by outside rain fog and sand dust, so that the optical surface is polluted by the sand dust in a short time, and the mirror surface needs to be regularly wiped and maintained; the optical surface coating will be corroded for a long time, and the optical device needs to be re-coated and adjusted. These problems have greatly affected the operation of open sunglasses.

Based on the background, the invention provides a foundation sealing inflatable solar telescope. The sealed lens cone is adopted, so that the advantage that the vacuum solar telescope can better protect optical devices is fully utilized; by filling inert gas, the pressure difference inside and outside the lens barrel is balanced, and the structural instability caused by the pressure difference is eliminated; meanwhile, the thermal control is carried out on the thermal diaphragm and the main mirror, so that the influence of the thermal deformation of the mirror surface and the local seeing effect is greatly reduced. The invention integrates the advantages of the existing vacuum type and open type solar telescopes, effectively avoids the respective defects, and has strong innovation and practicability.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the novel solar telescope scheme is provided, and the defects that the existing vacuum type solar telescope or open type solar telescope cannot effectively protect optical devices, has internal and external pressure difference, cannot control thermal effect and the like are effectively overcome.

The technical scheme adopted by the invention for solving the technical problems is as follows: a sealed inflatable solar telescope for ground is composed of main window-sealing glass, air inlet of lens cone, heat-light-diaphragm liquid inlet tube, primary mirror, four-way tube, air distributor, air inlet tube, back cover of primary mirror, sealed insulating layer, exhaust port of lens cone, heat-light-diaphragm liquid outlet tube, heat diaphragm, gas state monitor module and secondary mirror.

The ground-based sealed inflatable solar telescope comprises a lens cone part, a main lens chamber part, an optical part, a thermal control part and a sealing part. The lens cone part consists of main sealing window glass, a lens cone, a four-way joint and the upper surface of a sealing heat-insulating layer, and the parts are rigidly connected and sealed to form a lens cone closed space; the lower surface of the main mirror chamber part sealing heat insulation layer, the main mirror and the main mirror rear cover are combined, and the parts are in rigid linkage or close contact to form a main mirror chamber closed space; the optical part consists of a primary mirror, a secondary mirror and a heat diaphragm, and all the parts keep relative position relationship and play a role in turning light beams; the thermal control part consists of a thermal diaphragm liquid inlet pipe, an air distribution box and a thermal diaphragm liquid outlet pipe, and plays a role in thermally controlling the primary mirror and the thermal diaphragm; the sealing part consists of a lens barrel inflation inlet, a lens barrel exhaust outlet and a gas state monitoring module, and plays a role in sealing and state monitoring of gas in the lens barrel.

The core of the foundation sealed inflatable solar telescope is characterized in that the telescope structure can be filled with gas, and the specific inflation process is as follows: the method comprises the steps of filling dry gas into a closed space of a lens barrel through a lens barrel inflation inlet, discharging original gas in the lens barrel through a lens barrel exhaust port, displaying information such as gas pressure, humidity and temperature in the lens barrel in real time by a gas state monitoring module in the gas filling process, closing the lens barrel exhaust port after the original gas in the lens barrel is completely replaced, and closing the lens barrel inflation inlet after the pressure in the lens barrel meets requirements, so that the inflation process is completed.

A foundation sealed inflatable solar telescope has an active thermal control function on a thermal diaphragm and a primary mirror, wherein the primary mirror is cooled in an air cooling mode: and low-temperature gas is blown into each honeycomb unit of the main mirror from the air distribution box through the spray pipes to cool the back side of the main mirror panel, and the mirror surface temperature is cooled by utilizing the heat conduction characteristic of the main mirror panel. The hot diaphragm is cooled in a liquid cooling mode: the low-temperature cooling liquid enters the thermal diaphragm through the thermal diaphragm liquid inlet pipe, absorbs excessive heat by utilizing the heat conduction characteristic of the thermal diaphragm, cools the thermal diaphragm and flows back from the thermal diaphragm liquid outlet pipe.

The principle of the invention is as follows:

firstly, a closed lens barrel design is adopted to completely isolate an internal optical device of the telescope from the external environment, so that the purpose of protecting the internal optical device is achieved; secondly, dry inert gas is filled in the closed lens cone, and the pressure difference between the inside and the outside is kept in a very small range, so that the pressure difference between the inside and the outside of the lens cone is effectively reduced while the environmental stability in the lens cone is further maintained, and the structural stability of the telescope is improved; and finally, carrying out thermal control on the thermal diaphragm and the main mirror, reducing the thermal deformation of the main mirror and weakening the local seeing effect.

The invention has the four advantages of effective protection of optical devices, no obvious internal and external pressure difference, no obvious thermal effect and easy maintenance, and is realized by respectively adopting three technical schemes of a closed lens cone, inert gas filling and thermal control, and the technical principle is as follows:

the closed lens cone forms a closed space in the lens cone through the rigid connection of all structural parts and the action of the sealing rings, so that the optical device and the external environment are isolated, particularly the external adverse factors such as rain, fog and dust, and the like, and the function of protecting the optical device is achieved.

Inert gas fills through filling into dry inert gas in to the lens cone, cooperation gaseous state monitoring module, and maintainer can keep the less pressure differential between the inside and external environment of lens cone at any time, reaches the accurate balanced state of the inside and outside pressure differential of lens cone, has effectively solved the too big problem of the inside and outside pressure differential of traditional vacuum type telescope, and the less inside and outside pressure differential of while changes in keeping for a long time, greatly reduced the system regularly aerify the frequency of maintaining, change in the maintenance.

The heat control is to crossing the initiative cooling to hot diaphragm and primary mirror, reduces the difference in temperature of hot diaphragm surface and mirror surface and the interior ambient temperature of lens cone, can minimize local seeing effect and primary mirror heat altered shape that the difference in temperature brought, carries out effective control to the sun telescope heat effect, has guaranteed the imaging performance of telescope.

Compared with the prior art, the invention has the following advantages:

(1) according to the ground-based sealed inflatable solar telescope, the optical device is isolated from the external environment through the closed lens cone structure, the influence of rain fog and sand dust on the optical device is effectively avoided, and compared with the existing open type solar telescope, the ground-based sealed inflatable solar telescope can well protect the optical device.

(2) According to the ground-based sealed inflatable solar telescope provided by the invention, the scheme that the enclosed lens cone is filled with the inert gas and the small pressure difference between the inside and the outside of the lens cone is kept is adopted, so that the pressure difference between the inside and the outside of the lens cone is obviously reduced, and compared with the existing vacuum solar telescope, the instability of the structure of the lens cone caused by the large pressure difference between the inside and the outside of the lens cone is reduced.

(3) According to the ground-based sealed inflatable solar telescope, the thermal diaphragm and the primary mirror are subjected to thermal control, so that the thermal deformation and the local seeing effect of the primary mirror are effectively reduced, and the problem that the thermal deformation of the primary mirror cannot be eliminated by the existing vacuum type solar telescope is effectively solved.

(4) The ground-based sealed inflatable solar telescope provided by the invention has the advantages that the lens cone adopts a sealed design, so that the optical device can be effectively protected, and the pressure difference between the inside and the outside of the lens cone is small, so that the long-term maintenance of the pressure state is facilitated. Compared with the existing vacuum solar telescope and the existing open solar telescope, the solar telescope provided by the invention has the characteristics that the maintenance frequency can be obviously reduced.

In a word, the foundation sealing inflatable solar telescope provided by the invention can fully integrate the advantages of the existing vacuum type and open type solar telescopes, and effectively solves the problems that optical devices cannot be effectively protected, large pressure difference exists inside and outside the lens cone, thermal deformation of the mirror surface cannot be effectively controlled, the maintenance frequency is too high and the like in the design of the existing solar telescope.

Drawings

Fig. 1 is a sealed inflatable ground-based solar telescope.

Fig. 2 is an embodiment of a sealed inflatable ground-based solar telescope.

In the figure, 1 is main window sealing glass, 2 is a lens cone inflating opening, 3 is a lens cone, 4-1 is a heat light diaphragm liquid inlet pipe, 5 is a main lens, 6 is a cross joint, 7 is an air distribution box, 8-1 is an air inlet pipe, 9 is a main lens rear cover, 10 is a sealing heat-insulating layer, 11 is a lens cone exhaust opening, 4-2 is a heat light diaphragm liquid outlet pipe, 12 is a heat diaphragm, 13 is a gas state monitoring module, and 14 is a secondary lens.

Detailed Description

The invention is further described with reference to the following figures and specific examples.

As shown in fig. 1, the basic idea of the present invention is to integrate the advantages of the existing vacuum type solar telescope and the open type solar telescope, protect the internal optical devices by the sealed lens barrel, reduce the pressure difference inside and outside the lens barrel by inert gas filling, reduce the thermal effect by thermal control of the thermal diaphragm and the primary mirror, fully utilize the advantages of the existing solar telescope, and avoid the defects thereof.

The method comprises the following steps: the device comprises a main sealing window glass 1, a lens barrel charging port 2, a lens barrel 3, a thermal diaphragm liquid inlet pipe 4-1, a main lens 5, a cross joint 6, an air distribution box 7, an air inlet pipe 8-1, a main lens rear cover 9, a sealing heat-insulating layer 10, a lens barrel exhaust port 11, a thermal diaphragm liquid outlet pipe 4-2, a thermal diaphragm 12, a gas state monitoring module 13 and a secondary lens 14.

A sealed inflatable ground-based solar telescope comprises a lens cone part, a main lens chamber part, an optical part, a thermal control part and a sealing part. The lens cone part is positioned at the upper end of the telescope, the whole lens cone part consists of main sealing window glass 1, a lens cone 3, a four-way joint 6 and the upper surface of a sealing heat-insulating layer 10, and the parts are rigidly connected and sealed to form a lens cone closed space; the primary mirror chamber part is positioned at the lower end of the telescope, consists of the lower surface of a sealing heat-insulating layer 10, a primary mirror 5 and a primary mirror rear cover 9, and is fixedly connected with the upper end lens cone part to form a primary mirror chamber closed space; the optical part is composed of a primary mirror 5, a secondary mirror 14 and a thermal diaphragm 12, and the parts keep relative position and play a role of folding the light beam. Wherein, the secondary mirror 14, the thermal diaphragm 12 and the primary mirror 5 are respectively arranged from top to bottom; the thermal control part consists of a thermal diaphragm liquid inlet pipe 4-1, an air distribution box 7 and a thermal diaphragm liquid outlet pipe 4-2 and plays a role in thermally controlling the main mirror and the thermal diaphragm. Wherein, the thermal diaphragm liquid inlet pipe 4-1 and the thermal diaphragm liquid outlet pipe 4-2 pass through the lens cone 3 and are directly connected with the thermal diaphragm 12, and the air distribution box 7 is positioned at the lowest end and is directly connected with the main mirror 5; the sealing part consists of a lens barrel inflation inlet 2, a lens barrel exhaust outlet 11 and a gas state monitoring module 13, and plays a role in sealing and state monitoring of gas in the lens barrel. The lens cone gas charging port 2 and the lens cone gas discharging port 11 are located on the lens cone body, and the gas state monitoring module 13 is located in the lens cone.

The core of the foundation sealing inflatable solar telescope is that the telescope structure can be filled with gas, and the specific inflation process is as follows: the method comprises the steps that dry gas is filled into a closed space of a lens barrel through a lens barrel inflation inlet 2, original gas in the lens barrel is exhausted through a lens barrel exhaust port 11, in the gas filling process, a gas state monitoring module 13 displays information such as gas pressure, humidity and temperature in the lens barrel in real time, after the original gas in the lens barrel is completely replaced, the lens barrel exhaust port 11 is closed, and after the pressure in the lens barrel meets requirements, the lens barrel inflation inlet 2 is closed, so that the inflation process is completed.

A sealed inflatable solar telescope of ground possesses the initiative thermal control function to hot diaphragm and primary mirror, and primary mirror 5 adopts the air-cooled mode cooling: low-temperature gas is blown into each honeycomb unit of the main mirror 5 from the air distribution box 7 through the spray pipes to cool the back side of the main mirror panel, and the mirror surface temperature is cooled by utilizing the heat conduction characteristic of the main mirror panel. The hot diaphragm 12 is cooled in a liquid cooling mode: the low-temperature cooling liquid enters the thermal diaphragm through the thermal diaphragm liquid inlet pipe 4-1, absorbs the redundant heat by utilizing the heat conduction characteristic of the thermal diaphragm 12, cools the thermal diaphragm 12, and flows back from the thermal diaphragm liquid outlet pipe 4-2.

The primary mirror adopts a light structure, namely, a hollow cavity communicated with the outside exists in the mirror body, and the hollow cavity plays a role in weight reduction and cooling.

The closed space of the lens cone is filled with dry inert gas, such as nitrogen and helium, and the characteristics of the lens cone must meet the requirement that the optical machine parts in the lens cone and the coating film thereof are not influenced to generate chemical reaction at the working temperature of the telescope.

The closed space of the primary mirror chamber is filled with gas for cooling the primary mirror, and the gas must be ensured to be dry.

The sealed heat insulation layer 10 is used for filling a gap between the main lens 5 and the lens barrel structure and isolating the lens barrel closed space and the main lens chamber closed space. The sealing and insulating layer 10 must have good sealing and insulating properties.

The lens barrel charging port 2 and the lens barrel discharging port 11 are valves that can be opened and closed freely, and when the valves are closed, good airtightness is required.

The gas state monitoring module 13 is installed in the lens cone closed space and used for monitoring the gas state in the lens cone closed space in real time, and the detection amount comprises: gas pressure, gas temperature, gas humidity.

All electronic and liquid pipelines entering the closed space of the lens barrel and the main lens chamber need to be provided with electronic and liquid pipeline adapter ports with good air tightness on the structural parts of the lens barrel and the main lens chamber.

When the telescope is in a working state, the gas pressure in the closed space of the lens cone is not less than the local atmospheric pressure, and the optimal working state is that the gas pressure in the closed space of the lens cone always keeps a positive pressure within 5 percent relative to the local atmospheric pressure.

As shown in fig. 2: a concrete implementation scheme of a foundation sealing inflatable solar telescope,

the upper surfaces of the main sealing window glass 1, the lens cone 3, the four-way joint 6 and the sealing heat-insulating layer 10 form a lens cone closed space together; the lower surfaces of the main mirror rear cover 9 and the sealing heat-insulating layer 10 jointly form a main mirror chamber closed space; the primary mirror 5 and the secondary mirror 14 jointly form an optical system; the thermal diaphragm 12 and the blowing system of the main mirror 5 jointly constitute a thermal control system.

The inflation process for this particular embodiment is as follows: the air charging port of the lens cone is connected with a nitrogen tank through an air pipe, the air charging port of the lens cone and the exhaust port of the lens cone are opened simultaneously, dry nitrogen is continuously filled into the closed space of the lens cone, and the original air or nitrogen in the lens cone is exhausted through the exhaust port of the lens cone. In the gas filling process, the gas state monitoring module displays information such as gas pressure, humidity and temperature in the lens barrel in real time. And when the humidity is reduced and stabilized, closing the exhaust port of the lens cone, reducing the inflation amount, paying attention to the change of the gas pressure in the lens cone, and closing the valve of the inflation port of the lens cone when the gas pressure in the lens cone is 5% higher than the ambient atmospheric pressure, thus completing the inflation process. During the operation of the solar telescope, the change of the pressure, the humidity and the temperature of the gas in the lens barrel needs to be closely paid attention, and when the pressure is reduced or the humidity is increased, nitrogen needs to be replenished again.

In the working process of the specific embodiment, the main mirror (comprising the blowing system) 5 is connected with the refrigerating system, the refrigerating system continuously supplies low-temperature dry air to the blowing system, the back side of the main mirror panel is cooled by the following system, and the mirror surface is cooled by utilizing the heat conduction characteristic of the main mirror panel; the thermal diaphragm 12 is connected with a refrigerating system, and the refrigerating system continuously injects low-temperature cooling liquid into the thermal diaphragm to cool the thermal diaphragm in real time. The thermal control system can effectively reduce the mirror surface thermal deformation and the local seeing effect in the running process of the scheme.

The above description is only an embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can understand that the replacement or addition and subtraction within the technical scope of the present invention shall be covered within the scope of the present invention, therefore, the scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A kind of ground seals the inflatable solar telescope, characterized by: the lens barrel comprises a lens barrel part, a main lens chamber part, an optical part, a thermal control part and a sealing part, wherein the lens barrel part consists of main window sealing glass (1), a lens barrel (3), a cross joint (6) and the upper surface of a sealing heat-insulating layer (10), the main window sealing glass (1) is positioned at the uppermost end of the lens barrel, the lens barrel (3) is positioned at the upper end of the cross joint, and the cross joint (6) is positioned between the lens barrel (3) and an air distribution box (7); the primary mirror chamber part consists of a lower surface of a sealing heat-insulating layer (10), a primary mirror (5) and a primary mirror rear cover (9), and the lower surface of the sealing heat-insulating layer (10), the primary mirror (5) and the primary mirror rear cover (9) are rigidly connected or closely contacted to form a closed space of the primary mirror chamber part; the optical part consists of a primary mirror (5), a secondary mirror (14) and a thermal diaphragm (12), wherein the primary mirror (5) is positioned at the lower end of the four-way joint, the secondary mirror (14) is positioned at the uppermost end of the lens barrel, the thermal diaphragm (12) is positioned between the primary mirror (5) and the secondary mirror (14), and the primary mirror (5), the secondary mirror (14) and the thermal diaphragm (12) keep relative position relation to play a role in turning light beams; the thermal control part consists of a thermal diaphragm liquid inlet pipe (4-1), an air distribution box (7) and a thermal diaphragm liquid outlet pipe (4-2) and plays a role in performing thermal control on the main mirror (5) and the thermal diaphragm (12), wherein the thermal diaphragm liquid inlet pipe (4-1) and the liquid outlet pipe (4-2) penetrate through the lens cone (3) to be directly connected with the thermal diaphragm (12), and the air distribution box (7) is positioned at the lower end of the cross; the sealing part consists of a lens barrel inflation inlet (2), a lens barrel exhaust outlet (11) and a gas state monitoring module (13) and plays roles of sealing gas in the lens barrel and monitoring the state of the gas, wherein the lens barrel inflation inlet (2) and the lens barrel exhaust outlet (11) are positioned on the lens barrel body, and the gas state monitoring module (13) is positioned in the lens barrel;

dry gas is filled into the closed space of the lens cone through the lens cone inflating port (2), original gas in the lens cone is exhausted through a lens cone exhaust port (11), in the gas filling process, a gas state monitoring module (13) displays the gas pressure, humidity and temperature information in the lens cone in real time, after the original gas in the lens cone is completely replaced, the lens cone exhaust port (11) is closed, and after the pressure in the lens cone meets the requirement, the lens cone inflating port (2) is closed, so that the inflating process is completed;

the foundation sealed inflatable solar telescope has an active thermal control function on a thermal diaphragm and a primary mirror, and the primary mirror (5) is cooled in an air cooling mode: low-temperature gas is blown into each honeycomb unit of the main mirror (5) from the air distribution box (7) through the spray pipes, the back side of the main mirror panel is cooled, and the mirror surface temperature is cooled by utilizing the heat conduction characteristic of the main mirror panel; the hot diaphragm (12) is cooled in a liquid cooling mode: the low-temperature cooling liquid enters the thermal diaphragm through the thermal diaphragm liquid inlet pipe (4-1), absorbs the redundant heat by utilizing the heat conduction characteristic of the thermal diaphragm (12), cools the thermal diaphragm (12), and flows back from the thermal diaphragm liquid outlet pipe (4-2);

this sealed inflatable solar telescope of ground: firstly, a closed lens barrel design is adopted to completely isolate an internal optical device of the telescope from the external environment, so that the purpose of protecting the internal optical device is achieved; secondly, dry inert gas is filled in the closed lens cone, and the pressure difference between the inside and the outside is kept in a very small range, so that the pressure difference between the inside and the outside of the lens cone is effectively reduced while the environmental stability in the lens cone is further maintained, and the structural stability of the telescope is improved; and finally, carrying out thermal control on the thermal diaphragm and the main mirror, reducing the thermal deformation of the main mirror and weakening the local seeing effect.

2. The telescope of claim 1, wherein: the main mirror (5) is of a light structure, namely a hollow cavity communicated with the outside exists in the mirror body, and the hollow cavity plays a role in weight reduction and cooling.

3. The telescope of claim 1, wherein: the closed space of the lens cone (3) is filled with dry inert gas.

4. The telescope of claim 1, wherein: the closed space of the primary mirror chamber is filled with gas for cooling the primary mirror, and the gas must be ensured to be dry.

5. The telescope of claim 1, wherein: the sealing and heat insulating layer (10) is used for filling a gap between the main mirror (5) and the lens barrel (3) structure and isolating the closed space of the lens barrel and the closed space of the main mirror chamber, and the sealing and heat insulating layer (10) has good sealing property and heat insulating property.

6. The telescope of claim 1, wherein: the lens cone charging opening (2) and the lens cone exhaust opening (11) are valves which can be freely opened and closed, and when the valves are closed, good air tightness is required.

7. The telescope of claim 1, wherein: gas state monitoring module (13) are installed in lens cone (3) airtight space for carry out real-time supervision to lens cone (3) airtight space internal gas state, and the detection volume contains: gas pressure, gas temperature, gas humidity.

8. The telescope of claim 1, wherein: all electronic and liquid pipelines entering the closed space of the lens cone (3) and the main lens chamber need to be provided with electronic and liquid pipeline adapter ports with good air tightness functions on the structure parts of the lens cone (3) and the main lens chamber.

9. The telescope of claim 1, wherein: when the telescope is in working state, the gas pressure in the closed space of the lens cone is not less than the local atmospheric pressure.