Energy transmission window for traveling wave tube and preparation method

Abstract

The invention provides an energy transmission window for a traveling wave tube and a preparation method, and belongs to the technical field of electric vacuum devices. The energy transmission window comprises an outer conductor, an inner conductor and window porcelain, the outer conductor is of a coaxial annular composite structure and comprises a first annular part and a second annular part, the second annular part is brazed in the first annular part, the first annular part is made of molybdenum-copper alloy, and the second annular part is made of oxygen-free copper; the inner conductor is formed by brazing an energy transmission needle and an energy transmission needle sealing body, the inner conductor axially penetrates through the outer conductor from the energy transmission needle side, and the energy transmission needle sealing body is of a hollow structure; the window porcelain passes through the energy transmission needle sealing body and is vertically brazed with the energy transmission needle sealing body, and the outer circumference of the window porcelain is brazed with the inner side of the second annular part.

Description

Technical Field

[0001] The invention relates to the technical field of electric vacuum devices, and in particular to an energy transmission window for a traveling wave tube and a preparation method thereof. Background Art

[0002] A space traveling wave tube is a microwave vacuum device that uses the interaction between electron beams and electromagnetic waves to amplify signals. It is a core component of satellites and has the characteristics of high efficiency, high frequency band, and long life. It is currently the core component of large container communications, high-power space attack and defense, high-resolution radar, deep space exploration and other systems.

[0003] The space traveling wave tube exchanges energy with the traveling microwave field through electrons, so that the microwave signal is amplified and then output through the energy transmission window. Therefore, the energy transmission window of the traveling wave tube directly affects the degassing of the traveling wave tube, the size of high-frequency loss, the bandwidth, and the stability of the output power.

[0004] Traditional energy transmission windows generally adopt a coaxial structure with Kovar alloy as the outer conductor and molybdenum as the inner conductor. Due to the large stress between the inner conductor and the window porcelain needle seal and poor thermal matching, the Kovar alloy has insufficient heat dissipation capacity, resulting in excessive local temperature, which directly affects the airtightness of the window porcelain and metal seal, and the ability to resist temperature shock and mechanical vibration. It is difficult to meet the reliability requirements of L-Ku band space traveling wave tubes with a power of ≥1000W. Summary of the invention

[0005] In view of this, in order to at least partially solve at least one of the above-mentioned technical problems, the present invention provides an energy transmission window for a traveling wave tube and a preparation method thereof.

[0006] According to an embodiment of one aspect of the present invention, there is provided an energy transmission window for a traveling wave tube, comprising an outer conductor, an inner conductor and a window porcelain, wherein the outer conductor is arranged as a coaxial annular composite structure, comprising a first annular portion and a second annular portion, the second annular portion being brazed inside the first annular portion, the first annular portion being made of a molybdenum-copper alloy, and the second annular portion being made of oxygen-free copper; the inner conductor is brazed by an energy transmission needle and an energy transmission needle sealing body, the inner conductor axially penetrates the outer conductor from the energy transmission needle side, and the energy transmission needle sealing body is a hollow structure; the window porcelain passes through the energy transmission needle sealing body and is brazed vertically with the energy transmission needle sealing body, and the outer circumference of the window porcelain is brazed to the inner side of the second annular portion.

[0007] According to an embodiment of the present invention, the first annular portion and the second annular portion are clearance-fitted, and the fitting clearance is less than 0.06-0.08.

[0008] According to an embodiment of the present invention, the thickness of the first annular portion is 1-3 mm, the thickness of the second annular portion is less than or equal to 1 mm, and the thickness of the hollow structure of the energy transfer needle sealing body is 0.2-0.3 mm.

[0009] According to an embodiment of the present invention, the expansion coefficient of the material used for the first annular portion matches the expansion coefficient of the material used for the window porcelain.

[0010] According to an embodiment of the present invention, the first port diameter of the first annular portion is larger than the second port diameter of the first annular portion; the third port diameter of the second annular portion is larger than the fourth port diameter of the second annular portion.

[0011] According to another embodiment of the present invention, a method for preparing an energy transmission window is provided, characterized in that it includes:

[0012] An outer conductor is prepared by using a first brazing mold, and the outer conductor is turned to obtain a processed outer conductor, wherein the processed outer conductor is a coaxial annular composite structure, including a first annular portion and a second annular portion; a second brazing mold and a third brazing mold are provided, and the third brazing mold is assembled in the second brazing mold to form a brazing mold assembly; the outer conductor is assembled inside the third brazing mold of the brazing mold assembly; an energy transmission needle, an energy transmission needle sealing body and a window porcelain are assembled together, placed inside the outer conductor, and placed in a hydrogen furnace for welding to form an energy transmission window.

[0013] According to an embodiment of the present invention, an outer conductor is prepared using a first brazing mold, comprising: pre-treating a blank of the first annular portion and a blank of the second annular portion, placing the blank of the first annular portion inside the first brazing mold, and assembling the blank of the second annular portion inside the blank of the first annular portion to form a blank of an annular composite structure, wherein the material of the blank of the first annular portion is a molybdenum-copper alloy, and the material of the blank of the second annular portion is oxygen-free copper; placing a pressing block on the upper part of the blank of the annular composite structure, and welding it in a hydrogen furnace to form an outer conductor.

[0014] According to an embodiment of the present invention, the blank of the first annular part and the blank of the second annular part are pre-processed, including: cleaning the blank of the first annular part and the blank of the second annular part respectively; and silver coating the outer surface of the cleaned blank of the second annular part.

[0015] According to an embodiment of the present invention, the temperature of the hydrogen furnace for welding is 800°C and the vacuum degree is less than or equal to 5×10 - 3 Pa.

[0016] According to an embodiment of the present invention, the method further includes: placing solder at the connection between the energy transmission needle and the energy transmission needle sealing body, and placing solder at the connection between the window porcelain and the energy transmission needle sealing body.

[0017] According to an embodiment of the present invention, the outer conductor of a coaxial annular composite structure is formed by a first annular portion made of a molybdenum-copper alloy and a second annular portion made of oxygen-free copper. Since the thermal conductivity of the composite material of oxygen-free copper and molybdenum-copper alloy is significantly higher than the thermal conductivity of a single Kovar alloy of a conventional energy transmission window outer conductor, it can not only match the thermal expansion coefficient of ceramics and reduce the output loss of microwaves in the energy transmission window, but also improve the thermal conductivity of the energy transmission window. In addition, the energy transmission needle sealing body in the inner conductor adopts a hollow structure, which can reduce the sealing stress when the energy transmission window undergoes thermal changes, thereby improving the reliability of the energy transmission window structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0019] Figure 1 is a schematic structural diagram of an energy transmission window according to an embodiment of the present invention;

[0020] Figure 2 is a flow chart of a method for preparing an energy transmission window according to an embodiment of the present invention;

[0021] FIG3 (a) is a schematic diagram of preparing an outer conductor according to an embodiment of the present invention;

[0022] FIG3( b ) is a schematic diagram of the prepared outer conductor after processing;

[0023] Figure 4 It is a schematic diagram of assembling an energy transmission window according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] Below, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of embodiments of the present invention. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of concepts of the present invention.

[0025] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The term "comprising" used herein indicates the existence of features, steps, operations, but does not exclude the existence or addition of one or more other features.

[0026] In the case of using expressions such as "at least one of A, B, and C, etc.", it should generally be interpreted in accordance with the meaning of the expression generally understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.). In the case of using expressions such as "at least one of A, B, or C, etc.", it should generally be interpreted in accordance with the meaning of the expression generally understood by those skilled in the art (for example, "a system having at least one of A, B, or C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0027] The high-power, wide-bandwidth space traveling wave tube microwave transmission structure adopts a highly reliable sealed coaxial window. The structural feature is that the window porcelain and the outer conductor and inner conductor of the energy transmission window are highly reliable sealed to ensure that the space traveling wave tube can achieve high-power output under high vacuum.

[0028] In the related art, one structure of the outer conductor of the energy transmission window adopts a single material, for example, Kovar material, tungsten copper material, etc. Since the thermal conductivity of Kovar material is poor (about 20W / (m·K)) and the thermal conductivity of tungsten copper is high (about 220W / (m·K)), the difference in electrical conductivity causes large high-frequency losses. As the temperature rises, the expansion coefficients of tungsten copper and Kovar increase much more than that of ceramics. Since there is no structure to release expansion stress, thermal expansion causes structural mismatch, resulting in weld leakage and failure of the traveling wave tube. Another structure is that the outer conductor of the energy transmission window adopts thin-walled parts, mainly using Kovar 4J33, 4J34 and other materials. The main disadvantages are that the narrow heat dissipation path leads to excessive temperature and increased high-frequency losses, which is not conducive to high-power transmission of the traveling wave tube. Second, the structural strength is poor. When the energy transmission window is subjected to external force, the sealing surface is easily subjected to force, causing leakage and causing failure of the traveling wave tube.

[0029] Due to bandwidth requirements, the window ceramic and the inner conductor adopt a needle sealing structure that is difficult to seal. Since the needle has good rigidity, the ceramic is in a tensile stress state during contraction and expansion, which can easily cause leakage at the seal between the ceramic and the inner conductor. The reliability is low and it cannot be used in space traveling wave tube applications with power ≥1000W.

[0030] In view of this, the present invention proposes an energy transmission window for a traveling wave tube, so that the outer conductor composite structure of the energy transmission window can reduce the output loss of microwaves while improving the thermal conductivity of the energy transmission window, and can also make the ceramic and the sealing part highly reliable, so that the energy transmission window is suitable for space traveling wave tubes with power ≥1000W.

[0031] Figure 1 Schematic diagram of the structure of the energy transmission window according to an embodiment of the present invention.

[0032] like Figure 1 As shown, the energy transmission window can be used in a space traveling wave tube, and the energy transmission window includes an outer conductor 1, an inner conductor 2 and a window ceramic 3.

[0033] According to an embodiment of the present invention, the outer conductor 1 can be configured as a coaxial annular composite structure, including a first annular portion 1-1 and a second annular portion 1-2. The second annular portion 1-2 is brazed inside the first annular portion 1-1, the first annular portion 1-1 can be made of a molybdenum-copper alloy, and the second annular portion 1-2 can be made of oxygen-free copper.

[0034] According to an embodiment of the present invention, the first annular portion 1-1 may also be made of a material having high structural strength, moderate thermal conductivity and a coefficient of expansion matching that of ceramics. For example, in addition to molybdenum-copper alloy material, tungsten-copper alloy, molybdenum alloy, etc. may also be used.

[0035] According to an embodiment of the present invention, the first annular portion 1-1 of the outer conductor adopts a high thermal conductivity material matching the ceramic expansion coefficient, and the second annular portion 1-2 adopts an oxygen-free copper material to form an annular composite structure. Since the thermal conductivity of both is higher than the thermal conductivity of traditional Kovar alloy, the outer conductor using an annular composite structure can improve the thermal conductivity and heat dissipation capacity of the energy transmission window.

[0036] According to the embodiment of the present invention, the inner conductor 2 is formed by brazing the energy transmission pin 2-1 and the energy transmission pin sealing body 2-2. The inner conductor 2 axially penetrates the outer conductor 1 from one side of the energy transmission pin 2-1.

[0037] According to an embodiment of the present invention, the energy transmission needle 2-1 is a solid needle-shaped structure, and the energy transmission needle sealing body 2-2 is a hollow structure. The energy transmission needle 2-1 and the energy transmission needle sealing body 2-2 can be connected by brazing to form an inner conductor.

[0038] According to an embodiment of the present invention, the energy transmission needle sealing body 2-2 in the inner conductor 2 adopts a hollow structure, the purpose of which is to reduce the sealing stress and improve the reliability of the needle seam welding structure between the inner conductor and the window porcelain.

[0039] According to an embodiment of the present invention, the window ceramic 3 can pass through the energy transmission needle sealing body 2-2 and be brazed vertically with the energy transmission needle sealing body 2-2, the outer circumference of the window ceramic 3 is brazed with the inner side of the second annular portion 1-2 of the outer conductor; the inner hole side of the window ceramic 3 is brazed with a section of the outer circumference of the energy transmission needle sealing body 2-2.

[0040] According to an embodiment of the present invention, the first annular portion 1-1 and the second annular portion 1-2 in the outer conductor 1 are clearance-fitted, and the clearance is less than 0.06-0.08. The purpose is to facilitate processing during the preparation of the outer conductor by utilizing a certain gap between the first annular portion and the second annular portion.

[0041] According to an embodiment of the present invention, the expansion coefficient of the material used for the first annular portion 1-1 matches the expansion coefficient of the material used for the window porcelain 3, so that the annular composite structure can modulate the thermal expansion coefficient and match the expansion of the window porcelain. The selected oxygen-free copper and molybdenum-copper alloy are both non-magnetic, which can optimize the microwave output performance of the energy transmission window.

[0042] According to an embodiment of the present invention, the diameter of the first port a of the first annular portion 1-1 in the outer conductor 1 is larger than the diameter of the second port b of the first annular portion 1-1; similarly, the diameter of the third port c of the second annular portion 1-2 brazed inside the first annular portion 1-1 is larger than the diameter of the fourth port b of the second annular portion 1-2.

[0043] According to the embodiment of the present invention, the thickness of the first annular portion 1-1 in the outer conductor 1 is 1-3 mm, which is selected based on three factors: the design size of the energy transmission window, the structural strength of the outer conductor, and the thermal conductivity. In actual use, it can be appropriately increased according to actual needs.

[0044] According to an embodiment of the present invention, the thickness of the second annular portion 1-2 in the outer conductor 1 is ≤1 mm, preferably, the thickness may be 0.3-0.8 mm, so that the outer conductor has a suitable sealing stress to reduce the loss of the energy transmission window.

[0045] According to an embodiment of the present invention, the second annular portion of the outer conductor adopts oxygen-free copper, which is a metal with the highest thermal conductivity and low yield strength, to ensure sealing reliability and optimal heat dissipation near the window porcelain; the first annular portion of the outer conductor adopts molybdenum-copper, tungsten-copper, molybdenum, tungsten and other materials with good thermal conductivity, expansion coefficient matching the window porcelain and high yield strength to achieve heat dissipation, thereby ensuring that the composite structure adopted by the outer conductor of the energy transmission window has good external heat dissipation and structural strength.

[0046] According to an embodiment of the present invention, the energy transmission needle sealing body 2-2 in the inner conductor 2 is a hollow structure with a thickness of 0.2-0.3 mm. It is set from the perspectives of the structural strength of the metal material, the processing dimensions that can achieve vacuum airtightness, the microwave transmission path, etc., so that when the inner conductor changes thermally, the sealing stress can be better released through the plastic deformation of the inner conductor, so that the internal stress caused by thermal expansion and other reasons can be lower than the tensile strength of the ceramic and the weld, so as to obtain an energy transmission window with a high reliability structure.

[0047] According to the embodiment of the present invention, the inner conductor is made of oxygen-free copper or molybdenum with the highest thermal conductivity and has a hollow structure, thereby ensuring the reliability of welding between the inner conductor and the window porcelain.

[0048] Figure 2 Flow chart of a method for preparing an energy transmission window according to an embodiment of the present invention.

[0049] like Figure 2 As shown, the method may include: operation S210 to operation S240.

[0050] In operation S210, an outer conductor is prepared by using a first brazing mold, and the outer conductor is machined to obtain a machined outer conductor, wherein the machined outer conductor is a coaxial annular composite structure including a first annular portion and a second annular portion.

[0051] In operation S220, a second brazing mold and a third brazing mold are provided, and the third brazing mold is assembled into the second brazing mold to form a brazing mold assembly.

[0052] In operation S230, the outer conductor is assembled in the third soldering mold of the soldering mold assembly.

[0053] In operation S240, the energy transmission pin, the energy transmission pin sealing body and the window porcelain are assembled together, placed inside the outer conductor, and placed in a hydrogen furnace for welding to form an energy transmission window.

[0054] According to an embodiment of the present invention, preparing an outer conductor using a first brazing mold may include: after pre-treating the blank of the first annular part and the blank of the second annular part, placing the blank of the first annular part inside the first brazing mold, and assembling the blank of the second annular part inside the blank of the first annular part, wherein the material of the blank of the first annular part is molybdenum-copper alloy, and the material of the blank of the second annular part is oxygen-free copper; placing a pressing block on the upper part of the blank of the second annular part, and placing it in a hydrogen furnace for welding to form an outer conductor with an annular composite structure.

[0055] According to an embodiment of the present invention, the blank of the first annular portion may be a blank of a molybdenum-copper alloy, and the blank of the second annular portion may be a blank of an oxygen-free copper.

[0056] According to an embodiment of the present invention, pre-processing the blank of the first annular part and the blank of the second annular part respectively may include: cleaning the blank of the first annular part and the blank of the second annular part respectively; and silver coating the outer surface of the cleaned blank of the second annular part respectively.

[0057] According to the embodiment of the present invention, the blank of the first annular part and the blank of the second annular part can be cleaned and prepared separately, and then the outer surface of the blank of the second annular part can be silver-plated.

[0058] According to an embodiment of the present invention, the outer surface may be silver-plated by electroplating, magnetron sputtering, etc., and this application does not make any specific limitation thereto.

[0059] According to an embodiment of the present invention, the two blanks of the outer conductor 2 are processed. The inner blank, that is, the blank of the second annular part, is made of oxygen-free copper material, and the processed outer surface must meet a certain surface roughness, for example, the surface roughness can be better than 0.08; the outer blank, that is, the blank of the first annular part, is made of molybdenum-copper alloy, and the processed inner surface must meet a certain surface roughness, for example, the surface roughness can be better than 0.08. Then, the outer surface of the blank of the second annular part is silver-plated. The fitting clearance of the two blanks in the circumferential direction is controlled to be (0.3-0.6)D×10 -2 Within, where D is the diameter of the oxygen-free copper blank, the two blanks are welded, and the welding temperature is controlled between 780-800° C. The composite blank is machined to form the outer conductor of the energy transmission window.

[0060] FIG. 3 ( a ) is a schematic diagram of preparing an outer conductor according to an embodiment of the present invention; FIG. 3 ( b ) is a schematic diagram of the prepared outer conductor after processing.

[0061] As shown in Fig. 3 (a), the blank of the first annular part 1-1 can be placed inside the first brazing mold 4, and the blank of the second annular part 1-2 can be assembled inside the blank of the first annular part 1-1. A pressing block 5 is then placed on the upper part of the blank of the second annular part 1-2. The pressing block 5 places the first brazing mold 4 and the blank of the first annular part 1-1 and the blank of the second annular part 1-2 inside the first brazing mold 4, and is placed in a hydrogen furnace or a vacuum furnace at a temperature of 800°C, and the vacuum degree is better than 5×10 -3 Pa, and then heat preservation for 10 minutes. Remove the pressing block 5 and the first brazing mold 4 to obtain a blank of an outer conductor with an annular composite structure. The blank of an outer conductor with an annular composite structure is machined to obtain an outer conductor with an annular composite structure (as shown in FIG. 3 (b)).

[0062] Figure 4 It is a schematic diagram of assembling an energy transmission window according to an embodiment of the present invention.

[0063] like Figure 4As shown, the second brazing mold 6 and the third brazing mold 7 are assembled together, specifically the third brazing mold 7 is assembled in the second brazing mold 6, to form a brazing mold assembly; then the outer conductor 1 is assembled in the third brazing mold 7 of the brazing mold assembly, the energy transmission needle 2-1 in the inner conductor 2 is penetrated into the outer conductor 1, the energy transmission needle sealing body 2-2 in the inner conductor is placed on the upper part of the energy transmission needle 2-1, and the solder 8 is placed between the energy transmission needle 2-1 and the energy transmission needle sealing body 2-2; the outer surface of the window porcelain 3 The circumference of the window ceramic 3 is brazed with the inner side of the second annular portion of the outer conductor 1, and the inner hole of the window ceramic 3 is brazed with a section of the outer circle of the energy transmission needle sealing body 2-2, and a ceramic gasket 9 is placed at a part of the window ceramic 3, and solder 10 is placed at the position where the inner hole of the window ceramic 3 contacts the energy transmission needle sealing body 2-2, and solder 11 is placed at the position where the outer circumference of the window ceramic 3 contacts the second annular portion of the outer conductor 1, and a fourth brazing mold 12 is assembled above the window ceramic 3 to form the assembled energy transmission window components.

[0064] According to an embodiment of the present invention, the assembled energy transmission window components are placed in a hydrogen furnace for welding. The brazing temperature can be 1000°C ± 20°C, and a slow rise and slow fall heating curve is adopted. The heating rate in the high temperature stage is not more than 20°C / min, and the temperature is kept for 3 minutes, and then the temperature is lowered. All brazing molds and gaskets and other components are removed to form an energy transmission window structure, such as Figure 1 shown.

[0065] According to the embodiment of the present invention, due to the increase in vacuum and high-voltage insulation requirements for high-power space traveling wave tubes, ultra-vacuum needs to be obtained, so gold-based solders with low vapor pressure are used to achieve high-reliability sealed brazing of the outer conductor, window porcelain and inner conductor of the energy transmission window. Under the condition of high-temperature baking and degassing, it will not affect the high-voltage insulation. At the same time, due to the high yield strength and poor fluidity of gold-copper solder, the welding surface state, weld structure and welding parameters are crucial to the welding quality.

[0066] According to the embodiment of the present invention, the welding gap can be selected to be 0.06-0.08mm, and chamfers are required for drainage. The welding is positioned by plugging, the amount of solder is 1.5 times the gap, and the solder AuCu50 wire with a diameter of 0.3 is used. The heating rate is lower than 20℃ / min, the highest temperature is 1000℃, and the temperature is kept for 3 minutes. The temperature is lowered to 500℃, and the cooling rate is lower than 10℃ / min. After it is lower than 500℃, it is cooled with the furnace. Stress is generated during cooling, so the slow cooling method can ensure the slow release of welding stress. When the temperature drops from 410℃ to 240℃, AuCu50 is easy to transform into an orderly state to generate three brittle compounds of AuCu3, Au3Cu and AuCu. Therefore, the gas circulation is quickly cooled with the furnace to prevent the orderly transformation of AuCu50 solder.

[0067] According to the embodiment of the present invention, the formed energy transmission window can be tested for leakage rate, and the leakage rate is generally better than 1.0x10 -11 Pa·m 3 / s, the standing wave ratio of the slow-wave component is less than 1.5.

[0068] According to an embodiment of the present invention, the outer conductor of a coaxial annular composite structure is formed by a first annular portion made of a molybdenum-copper alloy and a second annular portion made of oxygen-free copper. Since the thermal conductivity of the composite material of oxygen-free copper and molybdenum-copper alloy is significantly higher than the thermal conductivity of a single Kovar alloy of a conventional energy transmission window outer conductor, it can not only match the thermal expansion coefficient of ceramics and reduce the output loss of microwaves in the energy transmission window, but also improve the thermal conductivity of the energy transmission window. In addition, the energy transmission needle sealing body in the inner conductor adopts a hollow structure, which can reduce the sealing stress when the energy transmission window undergoes thermal changes, thereby improving the reliability of the energy transmission window structure.

[0069] It should be noted that the terms "first", "second", "third", "fourth" and the like involved in the present invention are only for distinction and have no practical meaning. The above specific embodiments further illustrate the purpose, technical scheme and beneficial effects of the present invention in detail. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. An energy transmission window for a traveling wave tube, comprising an outer conductor, an inner conductor and a window ceramic, characterized in that: The outer conductor (1) is configured as a coaxial annular composite structure, comprising a first annular portion (1-1) and a second annular portion (1-2), the second annular portion (1-2) being brazed inside the first annular portion (1-1), the first annular portion (1-1) being made of a molybdenum-copper alloy, and the second annular portion (1-2) being made of oxygen-free copper; The inner conductor (2) is formed by brazing an energy transmission needle (2-1) and an energy transmission needle sealing body (2-2); the inner conductor axially penetrates the outer conductor (1) from the side of the energy transmission needle (2-1); and the energy transmission needle sealing body (2-2) is a hollow structure; The window porcelain (3) passes through the energy transmission needle sealing body (2-2) and is vertically brazed to the energy transmission needle sealing body (2-2), and the outer circumference of the window porcelain (3) is brazed to the inner side of the second annular portion (1-2).

2. The energy transmission window according to claim 1, characterized in that: The first annular portion (1-1) and the second annular portion (1-2) are clearance-matched, and the clearance is less than 0.06-0.

08.

3. The energy transmission window according to claim 1, characterized in that: The thickness of the first annular portion (1-1) is 1-3 mm, the thickness of the second annular portion (1-2) is less than or equal to 1 mm, and the thickness of the hollow structure of the energy transfer needle sealing body (2-2) is 0.2-0.3 mm.

4. The energy transmission window according to claim 1, characterized in that: The expansion coefficient of the material used for the first annular portion (1-1) matches the expansion coefficient of the material used for the window ceramic (3).

5. The energy transmission window according to claim 1, characterized in that: The diameter of the first port (a) of the first annular portion (1-1) is greater than the diameter of the second port (b) of the first annular portion (1-1); and the diameter of the third port (c) of the second annular portion (1-2) is greater than the diameter of the fourth port (d) of the second annular portion (1-2).

6. A method for preparing an energy transmission window according to any one of claims 1 to 5, characterized in that: include: An outer conductor is prepared using a first brazing mold (4), and the outer conductor is machined to obtain a machined outer conductor (1), wherein the machined outer conductor is a coaxial annular composite structure, comprising a first annular portion (1-1) and a second annular portion (1-2); Providing a second brazing mold (6) and a third brazing mold (7), and assembling the third brazing mold (7) into the second brazing mold (6) to form a brazing mold assembly; Assembling the outer conductor (1) in a third brazing mold (7) of the brazing mold assembly; The energy transmission needle (2-1), the energy transmission needle sealing body (2-2) and the window porcelain (3) are assembled together, placed inside the outer conductor (1), and placed in a hydrogen furnace for welding to form an energy transmission window.

7. The method according to claim 6, characterized in that The method of preparing the outer conductor using the first brazing mold (4) comprises: After pre-treating the blank of the first annular portion (1-1) and the blank of the second annular portion (1-2), the blank of the first annular portion (1-1) is placed inside a first brazing mold (4), and the blank of the second annular portion (1-2) is assembled inside the blank of the first annular portion (1-1), wherein the material of the blank of the first annular portion (1-1) is a molybdenum-copper alloy, and the material of the blank of the second annular portion (1-2) is oxygen-free copper; A pressing block (5) is placed on the upper part of the blank of the second annular portion (1-2), and the blank is placed in the hydrogen furnace for welding to form an outer conductor (1) having an annular composite structure.

8. The method according to claim 7, characterized in that The pre-processing of the blank of the first annular portion (1-1) and the blank of the second annular portion (1-2) comprises: Cleaning the blank of the first annular portion (1-1) and the blank of the second annular portion (1-2) respectively; The outer surface of the cleaned blank of the second annular portion (1-2) is subjected to a silver coating treatment.

9. The method according to claim 7, characterized in that: The temperature of the welding in the hydrogen furnace is 800℃ and the vacuum degree is less than or equal to 5×10 -3 Pa.

10. The method according to claim 6, further comprising: Solder is placed at the connection between the energy transmission needle (2-1) and the energy transmission needle sealing body (2-2), and solder is placed at the connection between the window porcelain (3) and the energy transmission needle sealing body (2-2).

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