Super second-generation image intensifier tube based on cold indium sealing structure and preparation method of super second-generation image intensifier tube

Abstract

The invention discloses a super second-generation image intensifier tube based on a cold indium seal structure and a preparation method thereof, and the super second-generation image intensifier tube comprises a polyalkali photoelectric cathode assembly, a metal ceramic tube shell, an indium layer, a fixed ring, a micro-channel plate, an air suction wire, and a fluorescent screen. The metal ceramic tube shell comprises an upper sealing ring, a straight ceramic ring I, a sealing ring I, a straight ceramic ring II, a sealing ring II, a straight ceramic ring III, a sealing ring III, a straight ceramic ring IV and an isolating ring; the indium layer is melted in the upper sealing ring through a vacuum indium process; the air suction wire is arranged between the third sealing ring and the isolating ring in a spot welding mode. The preparation method comprises the steps of polyalkali photoelectric cathode manufacturing, tube shell assembly processing, cold pressing indium sealing and sampling. According to the invention, the preparation of the super-second-generation image enhancement tube is decomposed into different ultrahigh vacuum chambers, so that the mutual interference among the processing processes of all parts is effectively avoided, the processes of photoelectric cathode assembly manufacturing, tube shell assembly processing and indium sealing integration are optimized to the greatest extent, and the performance of the device is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of photoelectric detection, and in particular relates to a super second-generation image intensifier tube based on a cold indium seal structure and a preparation method thereof. Background Art

[0002] The super second-generation image intensifier tube is a low-light night vision device that integrates vacuum optoelectronic technology, material growth technology, and fluorescent screen technology. It has the characteristics of high sensitivity, low detection limit, high signal-to-noise ratio, and strong anti-interference ability. As the core photoelectric detection device in the low-light detection system, it has a wide range of applications.

[0003] The super second generation image intensifier tube is mainly composed of a multi-alkali photocathode, an electron multiplier and a fluorescent screen, and adopts a double close-contact structure. Its working principle is to use the external photoelectric effect to convert the input radiation image into a microelectronic image. Its input surface is a photocathode, which receives light radiation and is excited to produce photoelectrons to realize the photoelectric conversion of the radiation image. The photoelectron image generated by the photocathode is accelerated and focused on the input surface of the electron multiplier through an electrostatic field. Under the action of the electron multiplier, the electron flow density of the photoelectron image is multiplied, thereby realizing image enhancement. The enhanced electronic image bombards the fluorescent screen to realize the conversion of the electronic image into an optical image. In addition, the super second generation image intensifier tube can transfer the imaging of the low-light image intensifier tube to the CCD or CMOS image sensor through relay optical elements such as light cones to replace the eyepiece in the figure, forming an ICCD or ICMOS low-light image sensor to realize digital output.

[0004] At present, conventional super-second-generation image intensifier tubes use thermal indium sealing to seal the multi-alkali photocathode component and the tube shell component in an ultra-high vacuum environment through indium tin alloy. The sealing temperature is generally 120℃~140℃. Under this temperature condition, indium tin is in a dispersed state. In the production of super-second-generation image intensifier tubes, it is necessary to seal the multi-alkali photocathode component and the tube shell component in an ultra-high vacuum environment (less than or equal to 1×10 - 6 Pa) to electronically flush the electron multiplier (MCP) in the tube shell assembly to remove residual gases such as H2O, N2, CO, CO2, etc. on the inner wall of the MCP channel. These gases will shorten the life of the MCP, increase the noise, and even affect the stability of the multi-alkali cathode. However, when making the hot indium-sealed super-second-generation image intensifier tube, the photocathode assembly and the tube shell assembly are under the same temperature conditions. On the one hand, the alkali metals in the cathode growth process will contaminate the tube shell assembly and increase the device noise; on the other hand, the vacuum degree of the tube making equipment is not as good as the vacuum degree during electronic cleaning in the cold state, which will cause the gas molecules to be re-adsorbed on the inner wall of the MCP channel, affecting the signal-to-noise ratio and cathode stability of the image intensifier tube. Therefore, studying a tube making technology with low-temperature growth of photocathode and cold indium sealing will help improve the comprehensive performance of the super-second-generation image intensifier tube. Summary of the invention

[0005] The purpose of the present invention is to provide a super second-generation image intensifier tube based on a cold indium sealing structure and a preparation method thereof, which solves the problems of alkali metal contamination in the tube shell component, residual gas molecule adsorption in the microchannel plate channel, and insufficient reaction of the surface activation layer due to the high growth temperature existing in the hot indium sealing technology.

[0006] In order to achieve the purpose of the present invention, on the one hand, the present invention provides a super second generation image intensifier tube based on a cold indium seal structure, comprising a multi-alkali photocathode assembly, a metal ceramic tube shell, an indium layer, a fixing ring, a microchannel plate, an air getter wire, and a fluorescent screen; the multi-alkali photocathode assembly is composed of an anti-halation glass, a metal electrode layer, a substrate layer, a Sb-Na buffer layer, a Sb-K-Na absorption layer, and a Sb-Cs activation layer from bottom to top; the metal ceramic tube shell is used for structural support and vacuum maintenance of the super second generation image intensifier tube; the indium layer is melted in the indium groove of the metal ceramic tube shell and is used for sealing the multi-alkali photocathode assembly and the metal ceramic tube shell; the fixing ring fixes the microchannel plate in the metal ceramic tube shell; the microchannel plate is used to multiply the photoelectrons converted by the multi-alkali photocathode assembly; the air getter wire is welded to the inside of the metal ceramic tube shell and is used for evaporation of the getter before sealing; the fluorescent screen is used for electron bombardment imaging.

[0007] Furthermore, the anti-halation glass serves as an optical window and is also used as a substrate for the multi-alkali photocathode, and the material used is borosilicate glass.

[0008] Furthermore, the metal electrode layer is annular and made of CrNi or CrNiCu.

[0009] Furthermore, the base layer is formed by vapor-depositing MgO or Al2O3 or HfO2 or Sb2O3 material on the surface of the anti-halation glass, the purity of the material is greater than 99.99%, and the thickness is 10-20 nm.

[0010] Furthermore, the indium purity of the indium layer is greater than 99.999%.

[0011] Furthermore, the fluorescent screen is welded to the metal ceramic shell by laser welding or argon arc welding, and the fluorescent powder of the fluorescent screen is selected from P22, P43, P45 or P46.

[0012] Furthermore, the metal ceramic tube shell includes an upper sealing ring, a straight ceramic ring one, a sealing ring one, a straight ceramic ring two, a sealing ring two, a straight ceramic ring three, a sealing ring three, a straight ceramic ring four, and an isolation ring, which are brazed together by copper or palladium silver copper or silver copper solder sheets; the indium layer is melted into the upper sealing ring by a vacuum indium process; the suction wire is spot welded between the sealing ring three and the isolation ring.

[0013] On the other hand, the present invention also provides a method for preparing a super second generation image intensifier tube based on a cold indium seal structure, comprising the following steps:

[0014] Step 1: Make the polyalkali photocathode:

[0015] 1-1: Connect the anti-halation glass with the annular metal electrode and the substrate layer deposited and the assembled cathode atmosphere to the cathode chamber for evacuation and baking and degassing. The maximum baking temperature is greater than or equal to 380°C and the holding time is greater than or equal to 12h. Degas the K, Na, and Cs evaporation sources under high temperature conditions;

[0016] 1-2: When the temperature of the cathode chamber drops to 190-200° C., the temperature is kept constant, and the light source is turned on to sequentially grow a Sb-Na buffer layer at 190-200° C. and a Sb-K-Na absorption layer at 195-210° C. on the substrate layer;

[0017] 1-3: After the Sb-K-Na absorption layer growth process is completed, the cathode chamber is cooled to 160° C., and then the Sb-Cs activation layer is formed. When the formation is completed, the temperature is 100-110° C., and the light source is turned off;

[0018] 1-4: After the cathode chamber is naturally cooled to below 60°C, the light source is turned on to perform surface Cs activation treatment;

[0019] 1-5: After the Cs activation treatment is completed, the light source is turned off, and the multi-alkali photocathode assembly is transferred to the pressure sealing chamber through the magnetic transfer rod;

[0020] Step 2: Processing the tube shell assembly:

[0021] 2-1: The prepared shell and tube assembly is transferred into the shell and tube chamber for vacuuming and baking and degassing. The maximum baking temperature is not less than 360℃;

[0022] 2-2: After the baking is completed and the tube shell chamber is cooled to room temperature, the suction wire is first used for degassing, and then the MCP in the tube shell assembly is electronically cleaned and degassed;

[0023] 2-3: After the electronic cleaning process is completed, the suction wire is evaporated;

[0024] 2-4: Transfer the tube and shell assembly to the pressure sealing chamber through the magnetic transfer rod;

[0025] Step 3: Cold Press Indium Seal:

[0026] 3-1: First, dock the multi-alkali photocathode assembly and the tube shell assembly in the pressure sealing chamber;

[0027] 3-2: Adjust the pressure head and gradually apply pressure on the parts to be sealed;

[0028] 3-3: After the sealing is completed, release the pressure;

[0029] Step 4: Sampling Chamber:

[0030] 4-1: The sealed sample is transferred to the sampling chamber through the magnetic transfer rod;

[0031] 4-2: The sampling chamber is degassed and the image intensifier tube is taken out.

[0032] Furthermore, the image intensifier tube is made up of four vacuum chambers, namely, a cathode chamber, a tube shell chamber, a pressure sealing chamber, and a sampling chamber, and adjacent chambers are interconnected by vacuum;

[0033] The cathode chamber is used for the growth of multi-alkali photocathode, and the working vacuum degree is less than or equal to 5×10 -7 Pa;

[0034] The tube shell chamber is used for baking and degassing of the metal tube shell assembly and electronic brushing and degassing, and the working vacuum degree is less than or equal to 5×10 -7 Pa;

[0035] The press-sealing chamber is used for the indium sealing of the multi-alkali cathode assembly and the metal tube shell assembly, and the working vacuum degree is less than or equal to 5×10 -8 Pa, the sealing pressure is 0~1000kg;

[0036] The sampling chamber is used to transfer the image intensifier tube after the indium seal is integrated from the pressure sealing chamber, and the working vacuum degree is less than or equal to 5×10 -6 Pa.

[0037] Furthermore, in the step 1-3, the Sb-Cs activation includes Cs evaporation and Sb-Cs co-evaporation; in the step 1-4, the Cs activation treatment is to evaporate Cs on the surface until the monitored photocurrent reaches a maximum and then begins to decrease, and then the introduction of Cs is stopped when the photocurrent drops to 85% of the peak current, and the temperature of the Cs activation treatment is 20 to 60°C.

[0038] Compared with the prior art, the significant progress of the present invention lies in that: the present invention decomposes the preparation of the super-second-generation image intensifier tube into different ultra-high vacuum chambers, effectively avoiding mutual interference between the processing processes of various components, optimizing the photocathode assembly production, tube shell assembly processing, and indium sealing integration process to the greatest extent, and realizing the improvement of device performance, which is mainly reflected in cathode sensitivity, signal-to-noise ratio, image quality, etc., among which the sensitivity of the multi-alkali photocathode produced by the cold indium sealing process can be improved by more than 10% compared with the hot indium sealing process.

[0039] In order to more clearly illustrate the functional characteristics and structural parameters of the present invention, further description is given below in conjunction with the accompanying drawings and specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0041] Figure 1 It is a cross-sectional view of the super second generation image intensifier tube based on the cold indium seal structure of the present invention;

[0042] Figure 2 is a structural diagram of a multi-alkali photocathode assembly of the present invention;

[0043] Figure 3 is a cross-sectional view of the metal ceramic tube shell of the present invention;

[0044] Figure 4 It is a schematic diagram of a vacuum system for manufacturing a super second generation image intensifier tube of the present invention;

[0045] Figure 5 It is a spectral response curve diagram of the multi-alkali photocathode of the present invention.

[0046] The accompanying drawings are marked as follows: 1-multi-alkali photocathode assembly, 2-metal ceramic shell, 3-indium layer, 4-fixing ring, 5-microchannel plate, 6-air suction wire, 7-fluorescent screen, 1a-anti-halation glass, 1b-annular metal electrode layer, 1c-base layer, 1d-Sb-Na buffer layer, 1e-Sb-K-Na absorption layer, 1f-Sb-Cs activation layer, 2a-upper sealing ring, 2b-straight ceramic ring one, 2c-sealing ring one, 2d-straight ceramic ring two, 2e-sealing ring two, 2f-straight ceramic ring three, 2g-sealing ring three, 2h-straight ceramic ring four, 2i-isolation ring. DETAILED DESCRIPTION

[0047] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0048] The invention discloses a super second generation image intensifier tube based on a cold indium seal structure, combined with Figure 1 , including a multi-alkali photocathode assembly 1, a metal ceramic tube shell 2, an indium layer 3, a fixing ring 4, a microchannel plate 5, an air suction wire 6, and a fluorescent screen 7.

[0049] Combination Figure 2The multi-alkali photocathode assembly 1 includes an anti-halation glass 1a, an annular metal electrode layer 1b, a base layer 1c, a Sb-Na buffer layer 1d, a Sb-K-Na absorption layer 1e, and a Sb-Cs activation layer 1f. The annular metal electrode layer 1b is CrNi or CrNiCu, and is made by magnetron sputtering or electron beam evaporation. The base layer 1c is deposited with MgO or Al2O3 or HfO2 or Sb2O3 material on the surface of the anti-halation glass 1a by electron beam evaporation, and the thickness is 10 to 20 nm.

[0050] Combination Figure 3 The metal ceramic tube shell 2 includes an upper sealing ring 2a, a straight ceramic ring 2b, a sealing ring 2c, a straight ceramic ring 2d, a sealing ring 2e, a straight ceramic ring 2f, a sealing ring 2g, a straight ceramic ring 4 2h, and an isolation ring 2i; each component is connected by copper, palladium silver copper or silver copper solder sheets, and the final metal ceramic tube shell 2 is obtained by a brazing process.

[0051] The indium layer 3 is melted in the upper sealing ring 2a by a vacuum indium process and is used as solder for sealing the multi-alkali photocathode assembly and the tube shell assembly.

[0052] The air suction wire 6 is spot welded between the sealing ring 2g and the isolation ring 2i, and is degassed and evaporated before the image intensifier tube components are indium sealed to achieve vacuum maintenance.

[0053] The fluorescent screen 7 and the metal ceramic tube shell 2 are welded into one body by laser welding or argon arc welding.

[0054] The microchannel plate 5 is assembled in the metal ceramic tube shell 2 through the fixing ring 4 .

[0055] Combination Figure 4 The present invention discloses a method for preparing a super second generation image intensifier tube based on a cold indium sealing structure, which includes the production of a multi-alkali photocathode, tube shell component processing, cold pressing indium sealing, and sampling.

[0056] The preparation of the multi-alkali photocathode comprises the following steps:

[0057] Step 1: Place the evaporated annular electrode and the anti-halation glass of the substrate layer and the assembled cathode fixture into the cathode chamber and evacuate to a vacuum state. When the vacuum degree is less than or equal to 1×10 -4 Pa, the temperature is raised to bake and degas, the maximum baking temperature is not less than 380℃, the holding time is not less than 12h, and the K, Na, and Cs evaporation sources are degassed under high temperature conditions;

[0058] Step 2: When the temperature of the cathode chamber drops to 190-200° C., the temperature is kept constant, the light source is turned on, and a Sb-Na buffer layer is grown on the substrate layer in an alternating manner of Sb / Na;

[0059] Step 3: The Sb-K-Na absorption layer is grown by continuous Na and alternating Sb / K. The number of Sb / K alternations is determined according to the thickness, and the growth temperature is maintained at 195-210°C.

[0060] Step 4: After the Sb-K-Na absorption layer growth process is completed, the cathode chamber is cooled to 160°C, and the Sb-Cs activation layer is prepared by alternating Sb / Cs. The whole process is kept slowly cooled, and the temperature is 100-110°C at the end, and the light source is turned off;

[0061] Step 5: When the cathode chamber is cooled to below 60°C, the light source is turned on to activate the surface Cs, and the sensitivity of the multi-alkali photocathode can be increased by more than 10%;

[0062] Step 6: After the Cs activation is completed, the light source is turned off, and the multi-alkali photocathode assembly is transferred to the pressure sealing chamber through the magnetic transfer rod.

[0063] During the manufacturing process of the multi-alkali photocathode, light with a constant illumination intensity is used to irradiate the back of the anti-halation window, and the growth of the film layer is controlled by a photocurrent monitoring method.

[0064] The tube shell assembly processing method comprises the following steps: firstly, transferring the components except the multi-alkali photocathode assembly to the tube shell chamber, evacuating the components and performing baking for degassing, wherein the maximum baking temperature is not less than 360°C and the holding time is not less than 12 hours; secondly, after the tube shell chamber is cooled to room temperature after baking, firstly performing degassing by suction wire, and then performing electronic brushing for degassing of the MCP in the tube shell assembly, wherein the amount of electronic brushing is determined in combination with the characteristics of the MCP itself; then, performing suction wire evaporation after the electronic brushing process is completed; and finally, transferring the tube shell assembly to the pressure sealing chamber via a magnetic transmission rod.

[0065] The cold-pressed indium sealing method comprises the following steps: firstly, transferring and docking the multi-alkali photocathode assembly and the tube shell assembly in the sealing chamber; then adjusting the pressure head to gradually apply pressure on the component to be sealed, wherein the pressure adjustment range is 0-1000kg, and judging whether the sealing is in place by an in-situ thickness detection device; after the sealing is completed, slowly releasing the pressure and lifting the pressure head; finally, transferring the sealed image intensifier tube to the sampling chamber by a magnetic transmission rod, and taking it out after the vacuum in the sampling chamber is broken.

[0066] The tube shell chamber is used for baking and degassing of the metal tube shell assembly and electronic brushing and degassing, and the working vacuum degree is less than or equal to 5×10 -7 Pa;

[0067] The press-sealing chamber is used for the indium sealing of the multi-alkali cathode assembly and the metal tube shell assembly, and the working vacuum degree is less than or equal to 5×10 -8 Pa;

[0068] The sampling chamber is used to transfer the image intensifier tube after the indium seal is integrated from the pressure sealing chamber, and the working vacuum degree is less than or equal to 5×10 -6 Pa.

[0069] In the step 4, the preparation of the Sb-Cs activation layer includes Cs evaporation and Sb-Cs co-evaporation; in the step 5, Cs activation is performed by evaporating Cs on the surface until the monitored photocurrent reaches a maximum and then begins to decrease, and then the introduction of Cs is stopped when the photocurrent drops to 85% of the peak current, and the temperature of the Cs activation treatment is 20 to 60°C.

[0070] Finally, combined Figure 5 The photocathode spectral response curve of the super second generation image intensifier tube prepared by the above method has a spectral response range of 400-940nm and has a higher response rate in the long-wave band.

[0071] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0072] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A super second generation image intensifier tube based on cold indium seal structure, characterized in that: It includes a multi-alkali photocathode assembly, a metal ceramic tube shell, an indium layer, a fixing ring, a microchannel plate, an air suction wire, and a fluorescent screen; The multi-alkali photocathode assembly is composed of anti-halation glass, a metal electrode layer, a substrate layer, a Sb-Na buffer layer, a Sb-K-Na absorption layer, and a Sb-Cs activation layer from bottom to top; The metal ceramic tube shell is used for structural support and vacuum maintenance of the super second generation image intensifier tube; The indium layer is melted in the indium groove of the metal ceramic tube shell and is used for sealing the multi-alkali photocathode assembly and the metal ceramic tube shell; The fixing ring fixes the microchannel plate in the metal ceramic shell; The microchannel plate is used to multiply the photoelectrons converted by the multi-alkali photocathode assembly; The getter wire is welded inside the metal ceramic tube shell and is used for evaporation of the getter before sealing; The fluorescent screen is used for electron bombardment imaging.

2. The second generation image intensifier tube based on cold indium seal structure according to claim 1, characterized in that: The anti-halation glass is used as an optical window and also as a substrate of a multi-alkali photocathode, and is made of borosilicate glass.

3. The second generation image intensifier tube based on cold indium seal structure according to claim 1, characterized in that: The metal electrode layer is ring-shaped and made of CrNi or CrNiCu.

4. The second generation image intensifier tube based on cold indium seal structure according to claim 1, characterized in that: The base layer is made of MgO or Al2O3 or HfO2 or Sb2O3 material deposited on the surface of the anti-halation glass, the purity of the material is greater than 99.99%, and the thickness is 10-20nm.

5. The second generation image intensifier tube based on cold indium seal structure according to claim 1, characterized in that: The indium purity of the indium layer is greater than 99.999%.

6. The second generation image intensifier tube based on cold indium seal structure according to claim 1, characterized in that: The fluorescent screen is welded to the metal ceramic shell by laser welding or argon arc welding, and the fluorescent powder of the fluorescent screen is selected from P22, P43, P45 or P46.

7. The second generation image intensifier tube based on cold indium seal structure according to claim 1, characterized in that: The metal ceramic tube shell includes an upper sealing ring, a straight ceramic ring 1, a sealing ring 1, a straight ceramic ring 2, a sealing ring 2, a straight ceramic ring 3, a sealing ring 3, a straight ceramic ring 4, and an isolation ring, which are brazed and connected by copper or palladium silver copper or silver copper solder sheets; the indium layer is melted in the upper sealing ring by a vacuum indium process; the suction wire is spot welded between the sealing ring 3 and the isolation ring.

8. A method for preparing a super second generation image intensifier tube based on a cold indium seal structure, characterized in that: The following steps are involved: Step 1: Make the polyalkali photocathode: 1-1: Connect the anti-halation glass with the annular metal electrode and the substrate layer deposited and the assembled cathode atmosphere to the cathode chamber for evacuation and baking and degassing. The maximum baking temperature is greater than or equal to 380°C and the holding time is greater than or equal to 12h. Degas the K, Na, and Cs evaporation sources under high temperature conditions; 1-2: When the temperature of the cathode chamber drops to 190-200° C., the temperature is kept constant, and the light source is turned on to sequentially grow a Sb-Na buffer layer at 190-200° C. and a Sb-K-Na absorption layer at 195-210° C. on the substrate layer; 1-3: After the Sb-K-Na absorption layer growth process is completed, the cathode chamber is cooled to 160° C., and then the Sb-Cs activation layer is formed. When the formation is completed, the temperature is 100-110° C., and the light source is turned off; 1-4: After the cathode chamber is naturally cooled to below 60°C, the light source is turned on to perform surface Cs activation treatment; 1-5: After the Cs activation treatment is completed, the light source is turned off, and the multi-alkali photocathode assembly is transferred to the pressure sealing chamber through the magnetic transfer rod; Step 2: Processing the tube shell assembly: 2-1: The prepared shell and tube assembly is transferred into the shell and tube chamber for evacuation and baking and degassing. The maximum baking temperature is not less than 360℃; 2-2: After the baking is completed and the tube shell chamber is cooled to room temperature, the suction wire is first used for degassing, and then the MCP in the tube shell assembly is electronically cleaned and degassed; 2-3: After the electronic cleaning process is completed, the suction wire is evaporated; 2-4: Transfer the tube and shell assembly to the pressure sealing chamber through the magnetic transfer rod; Step 3: Cold Press Indium Seal: 3-1: First, dock the multi-alkali photocathode assembly and the tube shell assembly in the pressure sealing chamber; 3-2: Adjust the pressure head and gradually apply pressure on the parts to be sealed; 3-3: After the sealing is completed, release the pressure; Step 4: Sampling Chamber: 4-1: The sealed sample is transferred to the sampling chamber through the magnetic transfer rod; 4-2: The sampling chamber is degassed and the image intensifier tube is taken out.

9. The method for preparing a super second generation image intensifier tube based on a cold indium seal structure according to claim 8, characterized in that: The image intensifier tube is made of four vacuum chambers, namely, a cathode chamber, a tube shell chamber, a pressure sealing chamber, and a sampling chamber, and adjacent chambers are interconnected by vacuum; The cathode chamber is used for the growth of multi-alkali photocathode, and the working vacuum degree is less than or equal to 5×10 -7 Pa; The tube shell chamber is used for baking and degassing of the metal tube shell assembly and electronic brushing and degassing, and the working vacuum degree is less than or equal to 5×10 -7 Pa; The press-sealing chamber is used for the indium sealing of the multi-alkali cathode assembly and the metal tube shell assembly, and the working vacuum degree is less than or equal to 5×10 -8 Pa, the sealing pressure is 0~1000kg; The sampling chamber is used to transfer the image intensifier tube after the indium seal is integrated from the pressure sealing chamber, and the working vacuum degree is less than or equal to 5×10 -6 Pa.

10. The method for preparing a super second generation image intensifier tube based on a cold indium seal structure according to claim 8, characterized in that: In the step 1-3, the Sb-Cs activation includes Cs evaporation and Sb-Cs co-evaporation; in the step 1-4, the Cs activation treatment is to evaporate Cs on the surface until the monitored photocurrent reaches a maximum and then begins to decrease, and then the introduction of Cs is stopped when the photocurrent drops to 85% of the peak current, and the temperature of the Cs activation treatment is 20 to 60°C.

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