Pre-cavity electron beam channel structure for suppressing parasitic oscillation of high-power gyrotron

Abstract

The invention discloses a pre-cavity electron beam channel structure for suppressing parasitic oscillation of a high-power gyrotron. The structure comprises a cathode end electron beam channel cylinder and a resonant cavity end electron beam channel cylinder which are communicated with each other, the cathode end electron beam channel cylinder comprises a cathode end outer cylinder and a cathode end inner cylinder which are sleeved and fixed together, and a first channel in a conical cylinder shape is formed in the cathode end outer cylinder; the resonant cavity end electron beam channel cylinder comprises a resonant cavity end outer cylinder and a resonant cavity end inner cylinder which are sleeved and fixed together, a second channel of a kidney-shaped cylindrical structure is formed in the resonant cavity end inner cylinder, the inner diameter of the second channel is gradually reduced from the two ends to the middle, and the interior of the resonant cavity end inner cylinder is further concaved inwards to form a plurality of inner holes which are not symmetric about the central axis. When the structure is used, the problems that in the prior art, a gyrotron parasitic oscillation suppression mode is complex in machining and high in cost, and parasitic oscillation of a low-frequency band cannot be effectively suppressed are solved.

Description

Technical Field

[0001] This invention relates to the field of gyrotron technology, and more specifically, to a pre-cavity electron injection channel structure for suppressing parasitic oscillations in high-power gyrotrons. Background Technology

[0002] A gyrotron is a device that utilizes the synchronous interaction between the gyrotron motion of relativistic electrons in a strong magnetic field and the electromagnetic field in a high-frequency resonant cavity, converting the kinetic energy of electrons into high-frequency electromagnetic wave energy. It is the core of the electron gyrotron resonant heating system in a controlled thermonuclear fusion device. The performance of the electron beam in the gyrotron determines the interaction efficiency, and improving the performance of the electron beam is an important way to improve the working efficiency of the gyrotron. There is a certain distance between the electron beam generated from the cathode and the resonant cavity. To ensure a vacuum environment, the electron beam is enclosed within this distance by a channel, called the electron beam channel. The electron beam channel contains a metal cylindrical structure. Under the influence of the magnetic field, the electron beam will excite electromagnetic waves with frequencies lower than the target frequency within the cylindrical structure, called parasitic oscillations. Experiments have shown that parasitic oscillation frequencies generally exist in two frequency bands: one band is slightly lower than the target frequency by about 10-30 GHz (e.g., the parasitic oscillation band of a 170 GHz gyrotron is 140-160 GHz), and the other band is 0.1-10 GHz. To suppress parasitic oscillations, the current main method is dielectric loading (such as application number CN202411957923.6). This method is not only complex and costly to process, but also difficult to effectively suppress parasitic oscillations in lower frequency bands.

[0003] Therefore, providing a cavity-front electron injection channel structure that can completely suppress parasitic oscillations in the cavity of a high-power gyrotube during use, while also reducing processing difficulty and cost, is a problem that this invention urgently needs to solve. Summary of the Invention

[0004] To address the aforementioned technical problems, the purpose of this invention is to overcome the issues that existing methods for suppressing parasitic oscillations in gyrocoupling tubes are not only complex and costly to manufacture, but also difficult to effectively suppress parasitic oscillations in lower frequency bands. Therefore, this invention provides a cavity-front electron beam channel structure that can completely suppress parasitic oscillations in the cavity of a high-power gyrocoupling tube during use, while also reducing manufacturing difficulty and cost.

[0005] To achieve the above objectives, the present invention provides a cavity-front electron beam channel structure for suppressing parasitic oscillations in high-power gyrotrons. The structure comprises: a cathode-end electron beam channel cylinder and a resonant cavity-end electron beam channel cylinder connected in series; wherein... The cathode end electron injection channel cylinder includes: a cathode end outer cylinder and a cathode end inner cylinder sleeved and fixed together, and the interior of the cathode end outer cylinder forms a first channel in the shape of a conical cylinder; The resonant cavity end electron injection channel cylinder includes a resonant cavity end outer cylinder and a resonant cavity end inner cylinder that are sleeved and fixed together. The interior of the resonant cavity end inner cylinder forms a second channel with an inner diameter that gradually decreases from both ends to the middle. Furthermore, the interior of the resonant cavity end inner cylinder is also recessed inward to form multiple non-central axis symmetrical inner holes.

[0006] Preferably, both the cathode end outer cylinder and the resonant cavity end outer cylinder are made of copper. The inner cylinder of the cathode end is made of silicon carbide material; The inner cylinder of the resonant cavity is made of stainless steel.

[0007] Preferably, the inner surface of the outer cylinder of the cathode end and the outer surface of the inner cylinder of the cathode end are closely attached together, and the two are fixed together by a plurality of spaced pins.

[0008] Preferably, the end face diameters of the two connecting ends of the first channel and the second channel are the same.

[0009] Preferably, an anode is provided at the end of the electron injection channel cylinder away from the resonant cavity, and a cathode is provided at the lower end port of the first channel.

[0010] Preferably, a resonant cavity is provided at the end of the electron injection channel cylinder that is away from the cathode end of the electron injection channel cylinder.

[0011] According to the above technical solution, the beneficial effects of the cavity pre-electron injection channel structure for suppressing parasitic oscillations of high-power gyrotrons provided by the present invention are as follows: through the resonant cavity end inner cylinder with an asymmetrical hole near the resonant cavity end and another cathode end electron injection channel cylinder near the cathode end, parasitic oscillations in the high-frequency band and low-frequency band are effectively suppressed, and the structure also effectively reduces the processing difficulty and cost.

[0012] Other features and advantages of the present invention will be described in detail in the following detailed description section; and all parts not covered in the present invention are the same as or can be implemented using the prior art. Attached Figure Description

[0013] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of a precavity electron beam channel structure for suppressing parasitic oscillations in a high-power gyrotube, provided in a preferred embodiment of the present invention.

[0014] Explanation of reference numerals in the attached figures 1 cathode 2 anode 3 pins, 4 female ends, outer tube 5. Inner cylinder at the cathode end; 6. Outer cylinder at the resonant cavity end. 7. Inner cylinder at the end of the resonant cavity; 8. Inner hole 9 resonant cavities, 10 electron beams Detailed Implementation The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0015] In this invention, unless otherwise stated, directional terms such as "upper," "lower," "inner," and "outer" in the terminology represent the orientation of the term in its normal use or are common terms understood by those skilled in the art, and should not be regarded as limitations on the term.

[0016] like Figure 1 As shown, this invention provides a cavity-front electron beam channel structure for suppressing parasitic oscillations in high-power gyrotrons. The structure includes: a cathode-end electron beam channel cylinder and a resonant cavity-end electron beam channel cylinder connected in series; wherein, The cathode end electron injection channel cylinder includes: a cathode end outer cylinder 4 and a cathode end inner cylinder 5 sleeved and fixed together, the interior of the cathode end outer cylinder 4 forming a first channel in the shape of a conical cylinder; the resonant cavity end electron injection channel cylinder includes a resonant cavity end outer cylinder 6 and a resonant cavity end inner cylinder 7 sleeved and fixed together, the interior of the resonant cavity end inner cylinder 7 forming a second channel with a waist-shaped cylindrical structure that is concave in the middle, and the interior of the resonant cavity end inner cylinder 7 is also concave inward to form a plurality of non-central axis symmetrical inner holes 8.

[0017] In the above scheme, when the structure is used in a strong magnetic field, the parasitic oscillations in the high-frequency band and low-frequency band are effectively suppressed by the inner cylinder 7 of the resonant cavity end with an asymmetrical hole near the resonant cavity end and another electron injection channel cylinder near the cathode end. Moreover, the structure also effectively reduces the processing difficulty and cost.

[0018] Regarding the location of the inner hole 8, it is formed inside the inner cylinder 7 at the resonant cavity end and covers the inner surface. However, its location is not symmetrical along the central axis of the inner cylinder 7 at the resonant cavity end. Figure 1 As can be seen in the vertical cross-sectional view of the inner cylinder 7 at the end of the resonant cavity, there is a row of inner holes 8 on both its left and right sides, but the two are not symmetrically distributed.

[0019] For the second channel of the waist-shaped cylindrical structure, its structure is such that the inner diameter gradually decreases from the lower end to the middle, and gradually increases from the middle to the upper end, thus forming a shape that is concave in the middle, and the inner diameter of the lower end of the second channel is also larger than the inner diameter of the upper end.

[0020] In a preferred embodiment of the present invention, the outer cylinder 4 at the cathode end and the outer cylinder 6 at the resonant cavity end are both made of copper; the inner cylinder 5 at the cathode end is made of silicon carbide; and the inner cylinder 7 at the resonant cavity end is made of stainless steel.

[0021] The inner cylinder 5 of the cathode end is made of silicon carbide material. Silicon carbide is a semiconductor ceramic, which can effectively absorb low-frequency parasitic oscillations and absorb space charge, thereby reducing the space charge effect. Copper material has good thermal conductivity, which can effectively dissipate the heat generated by the inner cylinder 5 at the cathode end and the inner cylinder 7 at the resonant cavity end, so as to achieve a good heat dissipation effect and improve the stability of the device.

[0022] In a preferred embodiment of the present invention, the inner surface of the outer cylinder 4 of the cathode end and the outer surface of the inner cylinder 5 of the cathode end are closely attached together, and the two are fixed together by a plurality of spaced pins 3.

[0023] The aforementioned fixing structure is reliable, simple, and easy to manufacture, effectively reducing costs. In actual use, it is generally fixed at the top and bottom of the outer cylinder 4 and the inner cylinder 5 at the cathode end using pins 3 and fixing holes. The close contact between the two surfaces effectively increases the contact area, thereby improving heat conduction and ensuring effective heat dissipation.

[0024] In a preferred embodiment of the present invention, the end face diameters of the two connecting ends of the first channel and the second channel are the same.

[0025] In a preferred embodiment of the present invention, an anode 2 is provided at the end of the electron injection channel cylinder away from the resonant cavity end, and a cathode 1 is provided at the lower end port of the first channel; a resonant cavity 9 is provided at the end of the electron injection channel cylinder away from the cathode end.

[0026] In the above scheme, the electron beam 10 emitted by the cathode 1 is processed in the first and second channels and then injected into the resonant cavity 9, which can suppress parasitic oscillations in front of the high-power gyrotube cavity.

[0027] In summary, the cavity electron beam channel structure for suppressing parasitic oscillations in high-power gyroscopes provided by this invention overcomes the problems of existing gyroscope oscillation suppression methods, which are not only complex and costly to manufacture, but also difficult to effectively suppress parasitic oscillations in lower frequency bands.

[0028] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0029] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0030] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A pre-cavity electron beam channel structure for suppressing parasitic oscillations in high-power gyrotrons, characterized in that, The structure includes: a cathode-end electron injection channel cylinder and a resonant cavity-end electron injection channel cylinder connected to each other; wherein... The cathode end electron injection channel cylinder includes: a cathode end outer cylinder (4) and a cathode end inner cylinder (5) sleeved and fixed together, and the interior of the cathode end outer cylinder (4) forms a first channel in the shape of a cone. The resonant cavity end electron injection channel cylinder includes a resonant cavity end outer cylinder (6) and a resonant cavity end inner cylinder (7) that are sleeved and fixed together. The inner cylinder (7) forms a second channel with a waist-shaped cylindrical structure whose inner diameter gradually decreases from both ends to the middle. The inner cylinder (7) also has multiple non-central axis symmetrical inner holes (8) formed inwardly.

2. The pre-cavity electron beam channel structure for suppressing parasitic oscillations in high-power gyrotrons according to claim 1, characterized in that, Both the cathode end outer cylinder (4) and the resonant cavity end outer cylinder (6) are made of copper. The inner cylinder (5) of the cathode end is made of silicon carbide material; The inner cylinder (7) of the resonant cavity is made of stainless steel.

3. The pre-cavity electron beam channel structure for suppressing parasitic oscillations in high-power gyrotrons according to claim 2, characterized in that, The inner surface of the outer cylinder (4) of the cathode end and the outer surface of the inner cylinder (5) of the cathode end are closely attached together, and the two are fixed together by a plurality of spaced pins (3).

4. The pre-cavity electron beam channel structure for suppressing parasitic oscillations in high-power gyrotrons according to claim 2, characterized in that, The end face diameters of the two connection ends of the first channel and the second channel are the same.

5. The pre-cavity electron beam channel structure for suppressing parasitic oscillations in high-power gyrotrons according to claim 2, characterized in that, An anode (2) is provided at the end of the electron injection channel cylinder away from the resonant cavity, and a cathode (1) is provided at the lower end port of the first channel.

6. The pre-cavity electron beam channel structure for suppressing parasitic oscillations in high-power gyrotrons according to claim 5, characterized in that, The resonant cavity (9) is provided at the end of the electron injection channel cylinder that is away from the cathode end of the resonant cavity.

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