Radial gradient loading structure of high-gain gyrotron traveling wave tube

Abstract

The invention discloses a radial gradual change loading structure of a high-gain gyrotron traveling wave tube, which comprises a gradual change attenuation ceramic section, a uniform attenuation ceramic section and a metal cylinder high-frequency interaction section which are sequentially nested at the periphery of an electron beam channel, the uniform attenuation ceramic section is also formed by sequentially connecting multiple stages of uniform attenuation ceramics, the outer diameters of the multiple stages of gradient attenuation ceramics are sequentially increased towards the uniform attenuation ceramic section, then the gradient attenuation ceramics are sleeved with gradient metal cylinders, and the gradient metal cylinders, the uniform attenuation ceramics and the heat insulation metal gaskets are the same in outer diameter; the gradual change metal cylinder, the uniform attenuation ceramic and the heat insulation metal gasket are sleeved with the loading section heat dissipation metal cylinder, that is, gradual increase attenuation is achieved through the radial gradual change attenuation ceramic structure, so that the gain and the bandwidth of the gyrotron traveling wave tube are improved, and the working stability of the gyrotron traveling wave tube is guaranteed.

Description

Technical Field

[0001] The invention relates to the field of vacuum electronic technology, in particular to a radial gradient loading structure of a high-gain gyrotron traveling wave tube. Background Art

[0002] Gyrotron traveling wave tubes are widely used in scientific research, industrial, military and civilian microwave electronic systems such as millimeter wave satellite imaging, satellite cataloging, precision weather forecasting, precision guidance, communications, electronic countermeasures, particle accelerators, microwave remote sensing, thermonuclear fusion, microwave energy applications, etc. The existing gyrotron traveling wave tubes use a periodic ceramic loading structure in the high-frequency structure, which belongs to the mutation attenuation mode. The periodic loading ceramic structure uses the mutation attenuation mode to achieve microwave amplification, which greatly affects the gain, bandwidth and working stability of the gyrotron traveling wave tube structure. Summary of the invention

[0003] The invention provides a high-gain gyrotron traveling wave tube radial gradient loading structure to solve the problem that the existing gyrotron traveling wave tube structure adopts a sudden attenuation mode and limits the gain, bandwidth and working stability of the gyrotron traveling wave tube structure.

[0004] The present invention provides a high-gain gyrotron traveling wave tube radial gradient loading structure, the gyrotron traveling wave tube comprises a gradient attenuation ceramic section, a uniform attenuation ceramic section and a metal cylinder high-frequency interaction section which are sequentially nested in the periphery of an electron injection channel, wherein the gradient attenuation ceramic section comprises a plurality of stages of gradient attenuation ceramics connected in sequence, and the uniform attenuation ceramic section comprises a plurality of stages of uniform attenuation ceramics connected in sequence, and the outer diameters of the plurality of stages of gradient attenuation ceramics increase sequentially toward the uniform attenuation ceramic section;

[0005] Heat-insulating metal gaskets are provided between each level of gradual attenuation ceramics, each level of uniform attenuation ceramics, and between the gradual attenuation ceramics and the uniform attenuation ceramics;

[0006] The gradient attenuation ceramic is sheathed with a gradient metal cylinder, and the gradient metal cylinder, the uniform attenuation ceramic and the insulating metal gasket have the same outer diameters, and a loading section heat dissipation metal cylinder is sheathed on the gradient metal cylinder, the uniform attenuation ceramic and the insulating metal gasket.

[0007] Optionally, the number of the gradient attenuation ceramics is greater than two.

[0008] Optionally, the number of the gradient metal cylinders is the same as the number of the gradient attenuation ceramics.

[0009] Optionally, the high-frequency interaction section of the metal cylinder is coaxially connected to the tail end of the heat dissipating metal cylinder of the loading section.

[0010] Optionally, the materials of the gradient attenuation ceramic and the uniform attenuation ceramic are both beryllium oxide.

[0011] Optionally, the metal cylinder high-frequency interaction section, the heat-insulating metal gasket and the gradient metal cylinder are all made of oxygen-free copper material.

[0012] Optionally, the thickness of each level of the gradually attenuated ceramic is the same, which is 2-5 mm.

[0013] Optionally, the thickness of each level of uniform attenuation ceramic is the same, which is 2-5 mm.

[0014] Optionally, the thickness of the thermal insulation metal gasket is 2-5 mm.

[0015] The beneficial effects of the present invention are as follows:

[0016] The present invention provides a high-gain gyrotron traveling wave tube. The high-gain gyrotron traveling wave tube of the present invention adopts a radially gradually attenuated ceramic structure, that is, a gradually increasing attenuation is achieved. Therefore, in the Ka millimeter wave band, the gain of the gyrotron traveling wave tube can be increased by more than 8.5dB, the bandwidth is increased by more than 0.5GHz, and its working stability is greatly improved. The structure has the advantages of convenient processing and simple process implementation.

[0017] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0019] Figure 1 It is a schematic structural diagram of a high-gain gyrotron traveling wave tube provided by an embodiment of the present invention;

[0020] Figure 2 It is a cross-sectional view of the existing cyclotron traveling wave tube periodically loaded structure;

[0021] Figure 3 It is the existing reference output peak power diagram;

[0022] Figure 4 is the input power of the existing periodically loaded structure;

[0023] Figure 5is the input power of the existing radial gradient loading structure;

[0024] Figure 6 It is the electron beam phase space diagram of the existing radial gradient loading structure;

[0025] Figure 7 It is the electron beam phase space diagram of the existing periodically loaded structure;

[0026] Figure 8 It is the field distribution diagram of the working mode of the existing radial gradient loading structure;

[0027] Fig. 9 It is the field distribution diagram of the existing periodically loaded structure working mode;

[0028] Description of the drawings: 1-first-stage gradual attenuation ceramics; 2-second-stage gradual attenuation ceramics; 3-third-stage gradual attenuation ceramics; 4-fourth-stage gradual attenuation ceramics; 5-fifth-stage gradual attenuation ceramics; 6-primary uniform attenuation ceramics; 7-first-stage gradual metal cylinder 1; 8-second-stage gradual metal cylinder 2; 9-third-stage gradual metal cylinder 3; 10-fourth-stage gradual metal cylinder 4; 11-fifth-stage gradual metal cylinder 5; 12-electron injection channel; 13-loading section heat dissipation metal cylinder; 14-insulation metal gasket; 15-final uniform attenuation ceramics; 16-high-frequency interaction section of metal cylinder; DETAILED DESCRIPTION

[0029] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not limit the present invention.

[0030] In view of the problem that the existing gyrotron traveling wave tube structure using a sudden attenuation method limits the gain, bandwidth and working stability of the gyrotron traveling wave tube structure, an embodiment of the present invention provides a high-gain gyrotron traveling wave tube, see Figure 1 The gyrotron traveling wave tube of the embodiment of the present invention comprises a gradually attenuated ceramic section, a uniform attenuation ceramic section and a metal cylinder high-frequency interaction section 16 which are sequentially nested in the periphery of the electron injection channel 12, wherein the gradually attenuated ceramic section comprises a plurality of gradually attenuated ceramics connected in sequence, namely, a first-stage gradually attenuated ceramic 1, a second-stage gradually attenuated ceramic 2, a third-stage gradually attenuated ceramic 3, a fourth-stage gradually attenuated ceramic 4, and a fifth-stage gradually attenuated ceramic 5, and the uniform attenuation ceramic section comprises a plurality of uniform attenuation ceramics connected in sequence, the uniform attenuation ceramics comprising a primary uniform attenuation ceramic 6 to a final uniform attenuation ceramic 16, and the outer diameters of the plurality of gradually attenuated ceramics increase sequentially toward the uniform attenuation ceramic section, and then the plurality of uniform attenuation ceramics of the present invention may comprise a first-stage uniform attenuation ceramic, a second-stage uniform attenuation ceramic, and so on;

[0031] It should be noted that the number of the multi-stage gradual attenuation ceramics and the multi-stage uniform attenuation ceramics in the embodiment of the present invention can be arbitrarily set according to actual needs, and the present invention does not make any specific limitation on this.

[0032] A heat-insulating metal gasket 14 is provided between each level of gradually attenuated ceramics, each level of uniformly attenuated ceramics, and between the gradually attenuated ceramics and the uniformly attenuated ceramics;

[0033] The gradient attenuation ceramic is sheathed with a gradient metal cylinder, which is matched one by one with the multi-stage gradient attenuation ceramics, that is, the gradient metal cylinder also includes multiple stages, and the inner diameter of each stage gradient metal cylinder matches the outer diameter of its corresponding gradient attenuation ceramic, that is, the inner diameter of the first-stage gradient metal cylinder 7 matches the outer diameter of its corresponding first-stage gradient attenuation ceramic 1, and then the second-stage gradient metal cylinder 8, the third-stage gradient metal cylinder 9, the fourth-stage gradient metal cylinder 10, and the fifth-stage gradient metal cylinder 11 are also matched with their corresponding gradient metal cylinders respectively.

[0034] Then the outer diameters of the gradient metal cylinder, the uniform attenuation ceramic 6 and the thermal insulation metal gasket 14 are the same, and a loading section heat dissipation metal cylinder is disposed outside the gradient metal cylinder, the uniform attenuation ceramic 6 and the thermal insulation metal gasket 14 .

[0035] When the high-gain gyrotron traveling wave tube radial gradient loading attenuation ceramic structure in the embodiment of the present invention is working, the high-energy electron beam passing through the area where the gradient attenuation ceramic is located is gradually attenuated and a gradually enhanced beam-wave interaction occurs. Since the attenuation does not undergo a sudden change, the gain, bandwidth and stability of the radial gradient loading ceramic structure can be effectively improved.

[0036] The existing gyrotron traveling wave tube adopts a periodic ceramic loading structure in its high frequency structure, which belongs to the sudden attenuation mode, such as Figure 2 As shown in the figure, the output power, gain, bandwidth and efficiency are limited. When all electrical parameters of the gyrotron traveling wave tube are consistent and the high frequency structure size is consistent, and the output pulse power is 270kW as a reference, as shown in the figure, Figure 3 The periodic loading of the ceramic structure requires an input power of 306W, as shown in Figure 4 As shown. However, the input power of the radial gradient loading ceramic structure is only 43W. Figure 5 The electron injection phase spatial distribution of the radial gradient loading ceramic structure and the periodic loading ceramic structure is shown in Figure 6 and Figure 7 The working mode of the radial gradient loading ceramic structure and the periodic loading ceramic structure is shown in the figure. Figure 8 and Fig. 9Simulations show that in the Ka millimeter wave band, at the same power level, the use of a radial gradient structure can increase the overall gain of the gyrotron traveling wave tube by more than 8.5 dB, the bandwidth can be increased by more than 0.5 GHz, and the operation is more stable and reliable.

[0037] The following will be combined Figure 1 The high-gain gyrotron traveling wave tube of the embodiment of the present invention is explained and illustrated in detail by a specific example:

[0038] like Figure 1 As shown, the high-gain gyrotron traveling wave tube radial gradient loading ceramic structure has a simple structure and is easy to manufacture. It is characterized in that the structure consists of a first-stage gradient attenuation ceramic 1, a second-stage gradient attenuation ceramic 2, a third-stage gradient attenuation ceramic 3, a fourth-stage gradient attenuation ceramic 4, a fifth-stage gradient attenuation ceramic 5, a plurality of uniform attenuation ceramics, a plurality of heat-insulating metal gaskets 14, a first-stage gradient metal cylinder 1, a second-stage gradient metal cylinder 2, a third-stage gradient metal cylinder 3, a fourth-stage gradient metal cylinder 4, a fifth-stage gradient metal cylinder 5, a loading section heat dissipation metal cylinder 13, a metal cylinder high-frequency interaction section 16 and an electron injection channel 12.

[0039] In specific implementation, the thickness of each level of gradual attenuation ceramic in the embodiment of the present invention is the same, which is 2-5 mm, the thickness of each level of uniform attenuation ceramic is the same, which is 2-5 mm, and the thickness of the thermal insulation metal gasket is 2-5 mm. Those skilled in the art can make any setting according to actual needs, and the present invention will not elaborate on this.

[0040] Specifically, all the gradually attenuated ceramics in the embodiments of the present invention have an inner diameter of R0, a height of L3, an outer diameter gradually changing from R1 to R6, wherein R1≤R2≤R3≤R4≤R5≤R6, and the material is beryllium oxide. And all the uniform attenuation ceramics in the present invention have an inner diameter of R0, an outer diameter of R6, a height of L3, and the material is beryllium oxide.

[0041] Furthermore, in the embodiment of the present invention, all the heat-insulating metal gaskets 14 have an inner diameter of R0, an outer diameter of R6, and a thickness of L4. They are coaxially embedded between each section of the attenuation ceramics to conduct heat and flow, and are made of oxygen-free copper.

[0042] In a specific implementation, the number of the gradually attenuated ceramics in the embodiment of the present invention is n, where n≥2.

[0043] Furthermore, in the embodiment of the present invention, all the gradient metal cylinders have an outer diameter of R6, a height of L3, an inner diameter that gradually changes from R1 to R6, and R1≤R2≤R3≤R4≤R5≤R6. They are coaxially nested with the gradient attenuation ceramics and coaxially connected to the left and right ends of the heat-insulating metal gasket, which plays a role in heat conduction and flow conduction, and are made of oxygen-free copper material.

[0044] In specific implementation, in the embodiment of the present invention, the number of the gradient metal cylinders is n, where n≥2, which is equal to the number of the gradient attenuation ceramics.

[0045] Furthermore, in the embodiment of the present invention, the inner diameter of the loading section heat dissipation metal cylinder 13 is R6, the outer diameter is R7, and the height is L2. All the attenuation ceramics, the gradient metal cylinder and the heat insulation metal gasket 14 are coaxially sealed in the loading section heat dissipation metal cylinder 13.

[0046] Furthermore, in the embodiment of the present invention, the metal cylinder high frequency interaction section 16 has an inner diameter of R0, an outer diameter of R7, and a height of L1, and is coaxially connected to the right end of the loading section heat dissipation metal cylinder 13.

[0047] The electron injection channel 12 in the embodiment of the present invention is a cylindrical structure with a radius of R0 and a length of L1+L2. Each section of the gradient attenuation ceramic and each section of the uniform attenuation ceramic are coaxially placed alternately with the heat-insulating metal gasket 14 and are sealed inside the loading section heat dissipation metal cylinder 13. The metal cylinder high-frequency interaction section 16 is coaxially connected to the right end of the loading section heat dissipation metal cylinder 13.

[0048] The embodiment of the present invention adjusts the attenuation by changing the outer diameter of the gradually attenuated ceramic, that is, changing the thickness of the attenuation ceramic. In this example, the attenuation is adjusted by changing the sizes of R1, R2, R3, R4, R5 and R6, and R1≤R2≤R3≤R4≤R5≤R6 is satisfied.

[0049] In general, when the radially gradient loaded attenuation ceramic structure of the high-gain gyrotron traveling wave tube of the embodiment of the present invention is working, the high-energy electron beam in the area where the gradient attenuation ceramic is located is gradually attenuated and a gradually enhanced beam-wave interaction occurs. Since the attenuation does not undergo a sudden change, the gain, bandwidth and stability of the radially gradient loaded ceramic structure can be effectively improved.

[0050] Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, and thus, the scope of the present invention should not be limited to the above embodiments.

Claims

1. A high-gain gyrotron traveling wave tube radial gradient loading structure, characterized in that: It comprises a gradually attenuated ceramic section, a uniform attenuated ceramic section and a metal cylinder high-frequency interaction section which are sequentially nested in the periphery of the electron injection channel, wherein the gradually attenuated ceramic section comprises a plurality of gradually attenuated ceramics connected in sequence, and the uniform attenuated ceramic section comprises a plurality of uniform attenuated ceramics connected in sequence, and the outer diameters of the plurality of gradually attenuated ceramics increase sequentially toward the uniform attenuated ceramic section; Heat-insulating metal gaskets are provided between each level of gradual attenuation ceramics, each level of uniform attenuation ceramics, and between the gradual attenuation ceramics and the uniform attenuation ceramics; The gradient attenuation ceramic is sheathed with a gradient metal cylinder, and the gradient metal cylinder, the uniform attenuation ceramic and the insulating metal gasket have the same outer diameters, and a loading section heat dissipation metal cylinder is sheathed on the gradient metal cylinder, the uniform attenuation ceramic and the insulating metal gasket.

2. The high-gain gyrotron traveling wave tube radial gradient loading structure according to claim 1, characterized in that: The number of the gradient attenuation ceramics is greater than two.

3. The high-gain gyrotron traveling wave tube radial gradient loading structure according to claim 2, characterized in that: The number of the gradient metal cylinders is the same as the number of the gradient attenuation ceramics.

4. The gyrotron traveling wave tube according to claim 1, characterized in that: The high-frequency interaction section of the metal cylinder is coaxially connected to the tail end of the heat dissipation metal cylinder of the loading section.

5. The high-gain gyrotron traveling wave tube radial gradient loading structure according to claim 1, characterized in that: The materials of the gradient attenuation ceramic and the uniform attenuation ceramic are both beryllium oxide.

6. The high-gain gyrotron traveling wave tube radial gradient loading structure according to claim 1, characterized in that: The metal cylinder high-frequency interaction section, the heat-insulating metal gasket and the gradient metal cylinder are all made of oxygen-free copper.

7. The high-gain gyrotron traveling wave tube radial gradient loading structure according to any one of claims 1 to 6, characterized in that: The thickness of each level of gradual attenuation ceramic is the same, both 2-5mm.

8. The high-gain gyrotron traveling wave tube radial gradient loading structure according to any one of claims 1 to 6, characterized in that: The thickness of each level of uniform attenuation ceramic is the same, both 2-5mm.

9. The high-gain gyrotron traveling wave tube radial gradient loading structure according to any one of claims 1 to 6, characterized in that: The thickness of the heat-insulating metal gasket is 2-5 mm.

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