Fabrication method of terahertz traveling wave tube based on electronic gas injection and orifice expansion technology and terahertz traveling wave tube

Abstract

This disclosure provides a method for fabricating a terahertz traveling wave tube based on electron injection vaporization and aperture expansion technology, as well as the terahertz traveling wave tube itself. The fabrication method includes: processing an initial electron channel in a high-frequency interaction component, the diameter of which is smaller than the designed diameter of the electron beam; aligning and welding the high-frequency interaction component with the electron gun; evacuating the terahertz traveling wave tube using a vacuum furnace; turning on the electron gun and accelerating electrons once using the anode; applying a high voltage to the tube body of the high-frequency interaction component to accelerate electrons a second time, the high voltage being greater than the anode voltage; wherein the material around the initial electron channel is vaporized and extracted using the electrons after the second acceleration.

Description

Technical Field

[0001] This disclosure relates to the field of microwave and millimeter-wave vacuum electronic devices, and in particular to a method for fabricating a terahertz traveling wave tube based on electronic gasification and hole expansion technology, and the terahertz traveling wave tube itself. Background Technology

[0002] Terahertz traveling wave tubes (TWTs), as high-power terahertz sources, have become a research hotspot both domestically and internationally due to their high power, high efficiency, and wide bandwidth. With the continuous improvement of TWT products' high-power, high-efficiency, and wide-bandwidth electromagnetic wave amplification capabilities in major atmospheric windows, various advanced short millimeter-wave and terahertz weapons and equipment will be driven towards practical application. The working principle of terahertz TWTs is consistent with that of traditional TWTs, relying on electrons synchronized with electromagnetic waves to transfer energy to the electromagnetic waves for amplification. They mainly consist of an electron gun, a high-frequency interaction system, a collector, input / output devices, and a magnetic focusing system.

[0003] Due to the size convergence effect, microwave power devices become increasingly smaller at higher frequencies. For example, the slow-wave channel diameter of a 220 GHz traveling-wave tube is only about 0.25 mm, while that of a 1.03 terahertz tube is about 0.1 mm. Through a series of specialized precision adjustment and welding devices, the manufacturing precision of terahertz traveling-wave tubes can reach 20-30 micrometers. However, these assembly errors account for more than 20% of the electron channel diameter, making alignment a core technological challenge in the development of high-frequency devices. In earlier years, when designing L-band traveling-wave tubes, the electron beam channel diameter was larger, reaching 5-6 mm, and the fill ratio could exceed 80%, resulting in very ideal electronic efficiency and coupling impedance.

[0004] The electron flow problem in terahertz traveling wave tubes is essentially a problem of intercepting irregular electrons. When the interception ratio exceeds a certain value, such as 50%, it significantly reduces DC power, increases heat dissipation, and may even lead to failure accidents where the extremely narrow channel closes after being bombarded by electrons. This invention aims to utilize the energy of electron bombardment, optimize electron beam parameters, and reconstruct the electron channel to obtain a high-flow, high-fill-ratio electron optical system, thereby transferring more electron energy to microwave signals. This will provide strong support for improving the performance stability, reliability, and microwave signal amplification capability of terahertz traveling wave tubes, promoting the widespread application of terahertz technology in fields such as communications and radar.

[0005] Due to size and weight requirements, space traveling wave tubes generally employ periodic permanent magnet focusing (PPM). The transmission of the electron beam inevitably involves pulsations, meaning the electron beam envelope periodically increases and decreases. The design of the electron channel's inner diameter necessitates allowing sufficient space to prevent electrons from striking the inner wall of the channel. Even uniform magnetic fields with large volume and weight will inevitably exhibit electron pulsations due to minute manufacturing errors.

[0006] In terms of assembly, terahertz traveling wave tubes require extremely high precision. Even minute assembly errors and welding deformations in the cathode, focusing electrode, anode, and magnetic field associated with the electron beam can lead to instability or performance degradation in electron beam transmission. Traditional assembly methods generally involve designing with strict tolerances and using manual adjustments to ensure the relative positions of parts. This method is inefficient and cannot fully guarantee precision. Summary of the Invention

[0007] In view of this, this disclosure provides a method for fabricating a terahertz traveling wave tube based on electron injection vaporization and orifice expansion technology, and a terahertz traveling wave tube that can achieve an extremely high electron injection filling ratio without significantly increasing the alignment and assembly requirements, and is applicable to terahertz traveling wave tubes with various forms of electron injection.

[0008] According to one aspect of the inventive concept of this disclosure, a method for fabricating a terahertz traveling wave tube based on electronic gas injection orifice expansion technology is provided, comprising:

[0009] An initial electron channel is fabricated in a high-frequency interaction component, the diameter of which is smaller than the design diameter of the electron beam;

[0010] Align and assemble the high-frequency interaction component with the electron gun;

[0011] The terahertz traveling wave tube is evacuated using a vacuum exhaust furnace.

[0012] The electron gun is turned on, and the electrons are accelerated once by the anode. A high voltage is applied to the tube of the high-frequency interaction component to accelerate the electrons a second time. The high voltage is greater than the voltage of the anode.

[0013] In this process, the material around the initial electron channel is vaporized and extracted using electrons that have undergone secondary acceleration.

[0014] According to some embodiments of this disclosure, after the electron gun is activated, the following steps are also included:

[0015] The electron flux is obtained by monitoring the current of the collecting electrode and calculating its ratio to the total current. When the electron flux is greater than a preset threshold, it indicates that the vaporization and pore expansion have ended.

[0016] According to some embodiments of this disclosure, the voltage applied to the tube of the electron gun and the high-frequency interaction component is a pulse voltage, and the duration of a single pulse voltage ranges from 10 ns to 200 ns.

[0017] According to some embodiments of this disclosure, the operation further includes the following after the electron flux exceeds a preset threshold:

[0018] Reduce the voltage applied to the tube of the high-frequency interaction component to be equal to or slightly higher than the anode potential, while extending the duration of a single pulse to the millisecond to second level, wherein the slightly higher range includes 0~1kV.

[0019] According to some embodiments of this disclosure, the voltage applied to the anode ranges from 15 to 30 kV, and the voltage difference between the tube of the high-frequency interaction component and the anode ranges from 50 to 100 kV.

[0020] According to some embodiments of this disclosure, the punching process using secondary accelerated electrons further includes the following operations:

[0021] The vacuum level inside the electron gun and the collecting electrode is monitored. When the vacuum level inside the electron gun or the collecting electrode is lower than the first preset threshold, the punching operation is temporarily stopped. The punching operation is restarted after the vacuum level is restored to the second preset threshold, wherein the second preset threshold is greater than the first preset threshold.

[0022] According to some embodiments of this disclosure, the preparation method described in the above embodiments is characterized in that, during the punching process using secondary accelerated electrons, the operation further includes:

[0023] The temperature of the tube body of the high-frequency interaction component is monitored, and the tube body is cooled by air cooling or water cooling. If the temperature of the tube body is higher than the first preset temperature, the punching operation is temporarily stopped. The punching operation is restarted after the temperature of the tube body drops back to the second preset temperature, wherein the second preset temperature is lower than the first preset temperature.

[0024] According to another aspect of the inventive concept of this disclosure, a terahertz traveling wave tube based on electronic gas injection orifice expansion technology is also provided, comprising:

[0025] An electron gun assembly, including a cathode, a focusing electrode, and an anode, is used to generate an electron beam;

[0026] A high-frequency interaction component includes an electronic channel, one end of which is centrally connected to the output terminal of the electron gun component. The electronic channel is adapted to exchange the energy of the electron beam into electromagnetic waves. The electronic channel is fabricated using the preparation method described in the above embodiments.

[0027] The collecting electrode is connected to the other end of the electron channel.

[0028] According to some embodiments of this disclosure, the terahertz traveling wave tube has three exhaust channels for evacuation, the three exhaust channels being respectively located in the region near the anode at the front end of the electron gun, at the tail end of the electron gun away from the anode, and at the end of the collector away from the high-frequency interaction component.

[0029] According to some embodiments of this disclosure, the collector is a multi-stage step-down collection structure for recovering the energy of electrons.

[0030] The method for fabricating a terahertz traveling wave tube based on electronic gas injection and orifice expansion technology provided in this disclosure has the following advantages compared to the prior art:

[0031] (1) Improving the electron fill ratio limit: Electron injection vaporization and orifice expansion technology can effectively increase the electron fill ratio through a specific process, bringing it close to or even reaching the theoretical electron fill ratio limit. This allows more electrons to participate in the energy exchange process with electromagnetic waves, thereby improving the amplification efficiency and output power of the traveling wave tube.

[0032] (2) It can reduce the alignment requirements. In traditional traveling wave tubes, the alignment accuracy between the electron beam and the slow wave structure has a significant impact on the device performance. However, terahertz traveling wave tubes based on electron beam vaporization and aperture expansion technology reduce the alignment accuracy requirements by optimizing the shape and distribution of the electron beam. This makes the manufacturing and debugging process simpler and improves the reliability and stability of the device.

[0033] (3) Increased power output: Due to the increased electron beam filling ratio, terahertz traveling wave tubes based on electron beam vaporization and orifice expansion technology can provide higher output power. This is of great significance for applications requiring high power output. Attached Figure Description

[0034] The above and other objects, features and advantages of this disclosure will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0035] Figure 1 A flowchart illustrating the fabrication method of a terahertz traveling wave tube based on electronic gas injection orifice expansion technology according to an embodiment of the present disclosure is shown.

[0036] Figure 2 A perspective view of a terahertz traveling wave tube according to an embodiment of the present disclosure is shown schematically;

[0037] Figure 3 yes Figure 2A cross-sectional view of a terahertz traveling wave tube shown;

[0038] Figure 4 yes Figure 3 The diagram shows a magnified view of a portion of the structure of a terahertz traveling wave tube.

[0039] The meanings of the reference numerals in the above figures are as follows:

[0040] 1-Electron gun assembly;

[0041] 101 - Cathode;

[0042] 102-Focusing electrode;

[0043] 103 - Anode;

[0044] 2-High-frequency interaction components;

[0045] 201-Electronic Channel;

[0046] 3-Collection pole;

[0047] 4-Exhaust pipe. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0049] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0050] All terms used herein, including technical and scientific terms, have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0051] When using expressions such as "at least one of A, B, and C," the meaning should generally be interpreted according to the understanding of someone skilled in the art. For example, "a system having at least one of A, B, and C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C. Similarly, when using expressions such as "at least one of A, B, or C," the meaning should generally be interpreted according to the understanding of someone skilled in the art. For example, "a system having at least one of A, B, or C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C.

[0052] It should also be noted that the directional terms mentioned in the embodiments, such as "up," "down," "front," "back," "left," and "right," are only for reference to the directions in the accompanying drawings and are not intended to limit the scope of protection of this disclosure. Throughout the drawings, the same elements are represented by the same or similar reference numerals. Conventional structures or constructions will be omitted where they may cause confusion in understanding this disclosure.

[0053] Figure 1 A flowchart illustrating the fabrication method of a terahertz traveling wave tube based on electronic gas injection orifice expansion technology according to an embodiment of the present disclosure is shown. Figure 2 A perspective view of a terahertz traveling wave tube according to an embodiment of the present disclosure is shown schematically; Figure 3 yes Figure 2 A cross-sectional view of a terahertz traveling wave tube shown; Figure 4 yes Figure 3 The diagram shows a magnified view of a portion of the structure of a terahertz traveling wave tube.

[0054] According to one aspect of the inventive concept of this disclosure, a method for fabricating a terahertz traveling wave tube based on electronic gas injection and orifice expansion technology is provided, such as... Figures 1 to 4 As shown, it includes operations S1 to S4.

[0055] According to some embodiments of this disclosure, operation S1 includes: fabricating an initial electron channel in a high-frequency interaction component, the diameter of the initial electron channel being smaller than the designed diameter of the electron beam.

[0056] According to some embodiments of this disclosure, operation S2 includes: aligning and assembling the high-frequency interaction component with the electron gun.

[0057] According to some embodiments of this disclosure, operation S3 includes: performing a vacuuming operation on the terahertz traveling wave tube using a vacuum exhaust furnace.

[0058] According to some embodiments of this disclosure, operation S4 includes: turning on the electron gun, accelerating electrons once using the anode, and applying a high voltage to the tube of the high-frequency interaction component to accelerate electrons a second time, wherein the high voltage is greater than the voltage of the anode.

[0059] In this process, the electrons, after being accelerated twice, vaporize the material around the initial electron channel and then extract it.

[0060] In this embodiment, the initial electron channel diameter fabricated in the high-frequency interaction component (slow-wave circuit) is smaller than the designed diameter of the electron beam, enabling the device to operate in a state with a high proportion of electron interception. This initial electron channel is subsequently bombarded by high-energy electrons, and the material interfering with the electron trajectory is vaporized and discharged from the traveling wave tube through a vacuum exhaust furnace, achieving the effect of aperture expansion. This allows the fabrication of a terahertz traveling wave tube with a very high electron filling ratio, and the coupling impedance can approach the theoretical limit.

[0061] According to some embodiments of this disclosure, the initial electron channel diameter fabricated on the slow-wave circuit is smaller than the designed diameter of the electron beam, enabling the device to operate in a state where a high proportion of electrons are intercepted. This initial electron channel is subsequently bombarded by high-energy electrons, and the material interfering with the electron trajectory is vaporized and discharged from the traveling wave tube through an exhaust pipe under the action of a vacuum pump, achieving the effect of expanding the aperture.

[0062] According to some embodiments of this disclosure, the electron gun mainly comprises three parts: a cathode, a focusing electrode, and an anode, with significant high-voltage insulation between them and the tube body. The cathode emits electrons, the focusing electrode shapes the electron trajectory, the anode initially accelerates the electrons, and the tube body potential can be much higher than the anode for secondary acceleration. The electrons, after secondary acceleration, are then directed into the initial electron channel.

[0063] According to some embodiments of this disclosure, after the electron gun is turned on, the method further includes: monitoring the collecting electrode current and calculating the ratio to the total current to obtain the electron flux. When the electron flux is greater than a preset threshold, it indicates that the vaporization and orifice expansion have ended.

[0064] According to some embodiments of this disclosure, the voltage applied to the tube of the electron gun and the high-frequency interaction component is a pulse voltage, and the duration of a single pulse voltage ranges from 10 ns to 200 ns.

[0065] According to some embodiments of this disclosure, after the electron flux exceeds a preset threshold, the operation further includes: reducing the voltage applied to the tube body of the high-frequency interaction component to be equal to or slightly higher than the anode potential, while extending the duration of a single pulse to the millisecond to second level, wherein the slightly higher range includes 0~1kV.

[0066] According to some embodiments of this disclosure, the voltage applied to the anode ranges from 15 to 30 kV, and the voltage difference between the tube body of the high-frequency interaction component and the anode ranges from 50 to 100 kV.

[0067] According to some embodiments of this disclosure, the process of punching using secondary accelerated electrons also includes the following operation: monitoring the vacuum level inside the electron gun and the collecting electrode; when the vacuum level inside the electron gun or the collecting electrode is lower than a first preset threshold, temporarily stopping the punching operation; and restarting the punching operation after the vacuum level recovers to a second preset threshold, wherein the second preset threshold is greater than the first preset threshold.

[0068] According to some embodiments of this disclosure, the preparation method described in the above embodiments is characterized in that, in the process of punching holes using secondary accelerated electrons, the method further includes: monitoring the temperature of the tube body of the high-frequency interaction component and cooling the tube body by means of air cooling or water cooling; if the temperature of the tube body is higher than a first preset temperature, the punching operation is temporarily stopped, and the punching operation is restarted after the temperature of the tube body is reduced to a second preset temperature, wherein the second preset temperature is lower than the first preset temperature.

[0069] According to some embodiments of this disclosure, the method for preparing terahertz traveling wave tubes based on electron injection vaporization and orifice expansion technology provided in this disclosure is applicable to various forms of electron injection terahertz traveling wave tubes, such as single cylindrical tubes, strip injection tubes, planar multi-injection tubes, and circumferential multi-injection tubes.

[0070] The technical solutions of this disclosure will be further elaborated below with reference to some specific implementations. It should be understood that the specific embodiments are only for the purpose of enabling those skilled in the art to better understand the technical solutions of this disclosure, and should not be construed as an inappropriate limitation on the scope of protection of this disclosure.

[0071] Example 1

[0072] A small-diameter initial electron channel is fabricated on the slow-wave circuit, with a diameter of 0.05 mm.

[0073] The centering, assembly, and drying of the entire tube are completed, and the manufacturing precision of the terahertz traveling wave tube is controlled within 20-30 micrometers.

[0074] On the drying rack, the vacuum pump unit is kept running continuously. By adjusting the voltage between the tube and the anode, the electron gun can be operated in electron aperture expansion mode and wave injection interaction mode.

[0075] First, the electron gun is adjusted to operate in electron aperture expansion mode. In this mode, the tube potential is higher than the anode potential, such as 50-100kV, the energizing time is shorter, such as 100ns, and a single pulse is used to expand the initial electron beam channel aperture on the slow wave circuit layer by layer using instantaneous high-energy electron beams.

[0076] During the reaming process, a fan or water cooling system is used to dissipate heat from the tube. Close attention is paid to changes in the surface temperature of the tube and the vacuum level inside the tube. If the vacuum level deteriorates, for example, to below 1.0 × 10⁻⁶ Pa, the reaming process is paused, and the vacuum pump unit is given sufficient operating time to allow the vacuum level inside the tube to recover to the ideal value.

[0077] The electron flux is calculated and observed by the ratio of the collecting electrode current to the total current. When a high proportion of electrons reach the collecting electrode, such as more than 95%, it indicates that the electron injection channel expansion is complete.

[0078] The electron gun is then returned to beam-wave interaction mode, where the tube body and anode are at the same potential, or tens to hundreds of volts. The purpose is to fine-tune the electron trajectory and produce long-duration pulses, such as those on the order of milliseconds or even seconds. This structure and testing method can produce terahertz traveling-wave tubes with very high electron fill ratios, coupling impedances approaching theoretical limits, low electron interception ratios, and sufficiently long and large microwave power outputs.

[0079] According to some embodiments of this disclosure, the manufacturing precision of the terahertz traveling wave tube is controlled between 20 and 30 micrometers by using specialized precision adjustment and welding equipment (e.g., a coordinate measuring machine).

[0080] It should be noted that traditional terahertz traveling wave tubes have high insulation capabilities between the cathode and anode, typically reaching 15-50 kV, while the anode can only withstand 2-5 kV insulation when directly short-circuited to the tube body. If the voltage between the cathode and anode is simply switched, and hundreds of kilovolts are used to pull electrons, the field strength in the cathode region will be too high, resulting in too much current being pulled out, excessive space charge force, and the electron trajectory will be inconsistent with that during normal operation. If only the voltage required for normal operation of the terahertz traveling wave tube, such as 20-25 kV, is used, the electron energy is insufficient to achieve the effect of vaporization and orifice expansion. Prolonged bombardment will also cause the material around the inner wall of the orifice to melt, forming molten metal balls that accumulate around the channel and damage the structure of the slow-wave circuit.

[0081] According to some embodiments of this disclosure, the completion of aperture enlargement does not mean that all initial electron channel regions have been enlarged to a certain value. Rather, depending on the electron pulse trajectory, some regions may be enlarged to a diameter of 0.07 mm, and some regions may be enlarged to a diameter of 0.09 mm.

[0082] Example 2

[0083] In operation S4, the parameters in Table 1 can be used to set the positions of each structure.

[0084] Table 1

[0085]

[0086] According to another aspect of the inventive concept of this disclosure, a terahertz traveling wave tube based on electronic gas injection orifice expansion technology is also provided, such as... Figures 2 to 4 As shown, the terahertz traveling wave tube includes an electron gun assembly, a high-frequency interaction assembly, and a collector electrode. The electron gun assembly 1 includes a cathode 101, a focusing electrode 102, and an anode 103, and is used to generate an electron beam. The high-frequency interaction assembly 2 includes an electron channel 201, one end of which is centered and connected to the output terminal of the electron gun assembly 1. The electron channel 201 is suitable for exchanging the energy of the electron beam into electromagnetic waves, and is fabricated using the method described above. The collector electrode 103 is connected to the other end of the electron channel 201.

[0087] According to some embodiments of this disclosure, the terahertz traveling wave tube has three exhaust channels 4 for vacuuming, which are respectively located at the front end of the electron gun near the anode 103, at the tail end of the electron gun away from the anode 103, and at the end of the collector electrode 3 away from the high-frequency interaction component 2.

[0088] In this embodiment, the exhaust duct 4, located near the anode 103 at the front end of the electron gun, has its vacuum port positioned between the electron gun and the high-frequency interaction component. This is to prevent high-frequency exhaust gases from diffusing into the cathode region. The vacuum port of the exhaust duct 4, located at the tail end of the electron gun away from the anode 103, is situated at the tail end of the cathode and is used to exhaust gases released during high-temperature operation in the cathode region. A section located at the end of the collecting electrode 3 away from the high-frequency interaction component 2 is used to exhaust evaporated gases that have diffused there.

[0089] According to some embodiments of this disclosure, the electron gun assembly 1 is a multilayer encapsulated electron gun capable of generating a suitable electron beam with a desired shape and a velocity slightly faster than the phase velocity of electromagnetic waves, so as to facilitate energy exchange with electromagnetic waves.

[0090] According to some embodiments of this disclosure, the high-frequency interaction component 2 is the core part of the traveling wave tube, and its main function is to reduce the phase velocity of the electromagnetic wave so that it is "synchronized" with the velocity of the electron beam, so that the energy of the electron beam can be exchanged to the electromagnetic wave to the maximum extent.

[0091] According to some embodiments of this disclosure, a PPM (Periodic Permanent Magnet) magnetic focusing system is also included to confine the electron beam so that it is not intercepted by the slow-wave structure and thus loses energy, while bringing the electron beam as close as possible to the slow-wave structure to complete sufficient energy exchange.

[0092] According to some embodiments of this disclosure, the main function of the collecting electrode 3 is to collect the electron beam that has been applied and recover a portion of the DC energy to improve the overall tube efficiency.

[0093] According to some embodiments of this disclosure, the collecting electrode 3 is a multi-stage step-down collecting structure used to recover the energy of electrons.

[0094] According to some embodiments of this disclosure, the metal material of the collecting electrode 3 has more direct contact surfaces with the outer casing, without ceramic or vacuum isolation in between, resulting in low thermal resistance and better heat dissipation performance.

[0095] According to some embodiments of this disclosure, the collector electrode 3 has a compact structure and is easy to manufacture: the three-electrode step-down collector electrode has a relatively simple and compact structure, making it easy to manufacture and integrate into the microwave tube. This not only reduces production costs but also helps improve the reliability and maintainability of the device.

[0096] According to some embodiments of this disclosure, the collector electrode 3 is easily adjustable and optimized. By adjusting the potential and shape between the electrodes, the performance of the three-electrode step-down collector electrode can be optimized. This flexibility allows the collector electrode to adapt to different working environments and application requirements, improving its adaptability and versatility.

[0097] According to some embodiments of this disclosure, the terahertz traveling wave tube also includes an input / output coupling device, which is the mechanism for inputting and outputting high-frequency energy in the traveling wave tube. Taking a 1.03 THz traveling wave tube as an example, the external interface of the terahertz traveling wave tube of this invention adopts a WR1.0 rectangular waveguide, with the length and width of the rectangle being 0.2540 mm * 0.1270 mm, respectively.

[0098] The method for fabricating a terahertz traveling wave tube based on electronic gas injection and orifice expansion technology provided in this disclosure has the following advantages compared to the prior art:

[0099] (1) Improving the electron fill ratio limit: Electron injection vaporization and orifice expansion technology can effectively increase the electron fill ratio through a specific process, bringing it close to or even reaching the theoretical electron fill ratio limit. This allows more electrons to participate in the energy exchange process with electromagnetic waves, thereby improving the amplification efficiency and output power of the traveling wave tube.

[0100] (2) It can reduce the alignment requirements. In traditional traveling wave tubes, the alignment accuracy between the electron beam and the slow wave structure has a significant impact on the device performance. However, terahertz traveling wave tubes based on electron beam vaporization and aperture expansion technology reduce the alignment accuracy requirements by optimizing the shape and distribution of the electron beam. This makes the manufacturing and debugging process simpler and improves the reliability and stability of the device.

[0101] (3) Increased power output: Due to the increased electron beam filling ratio, terahertz traveling wave tubes based on electron beam vaporization and orifice expansion technology can provide higher output power. This is of great significance for applications requiring high power output.

[0102] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. A method for fabricating a terahertz traveling wave tube based on electronic gas injection and orifice expansion technology, characterized in that, include: An initial electron channel is fabricated in a high-frequency interaction component, the diameter of which is smaller than the design diameter of the electron beam; Align and assemble the high-frequency interaction component with the electron gun; The terahertz traveling wave tube is evacuated using a vacuum exhaust furnace. The electron gun is turned on, and the electrons are accelerated once by the anode. A high voltage is applied to the tube of the high-frequency interaction component to accelerate the electrons a second time. The high voltage is greater than the voltage of the anode. In this process, the material around the initial electron channel is vaporized and extracted using electrons that have undergone secondary acceleration.

2. The preparation method according to claim 1, characterized in that, After the electron gun is activated, the following is also included: The electron flux is obtained by monitoring the current of the collecting electrode and calculating its ratio to the total current. When the electron flux is greater than a preset threshold, it indicates that the vaporization and pore expansion have ended.

3. The preparation method according to claim 1, characterized in that, The voltage applied to the tube of the electron gun and the high-frequency interaction component is a pulse voltage, and the duration of a single pulse voltage ranges from 10ns to 200ns.

4. The preparation method according to claim 2, characterized in that, After the electron flux exceeds a preset threshold, the following operation is also included: Reduce the voltage applied to the tube of the high-frequency interaction component to be equal to or slightly higher than the anode potential, while extending the duration of a single pulse to the millisecond to second level, wherein the slightly higher range includes 0~1kV.

5. The preparation method according to claim 1, characterized in that, The voltage applied to the anode ranges from 15 to 30 kV, and the voltage difference between the tube of the high-frequency interaction component and the anode ranges from 50 to 100 kV.

6. The preparation method according to claim 1, characterized in that, The process of punching holes using secondary accelerated electrons also includes the following operations: The vacuum level inside the electron gun and the collecting electrode is monitored. When the vacuum level inside the electron gun or the collecting electrode is lower than the first preset threshold, the punching operation is temporarily stopped. The punching operation is restarted after the vacuum level is restored to the second preset threshold, wherein the second preset threshold is greater than the first preset threshold.

7. The preparation method according to claim 1, characterized in that, According to the preparation method of claim 1, the process of punching holes using secondary accelerated electrons further includes the following operation: The temperature of the tube body of the high-frequency interaction component is monitored, and the tube body is cooled by air cooling or water cooling. If the temperature of the tube body is higher than the first preset temperature, the punching operation is temporarily stopped. The punching operation is restarted after the temperature of the tube body drops back to the second preset temperature, wherein the second preset temperature is lower than the first preset temperature.

8. A terahertz traveling wave tube based on electronic gas injection orifice expansion technology, characterized in that, include: An electron gun assembly, including a cathode, a focusing electrode, and an anode, is used to generate an electron beam; A high-frequency interaction component includes an electronic channel, one end of which is centered and connected to the output end of the electron gun component. The electronic channel is adapted to exchange the energy of the electron beam into electromagnetic waves, wherein the electronic channel is generated by the preparation method according to any one of claims 1 to 7. as well as The collecting electrode is connected to the other end of the electron channel.

9. The terahertz traveling wave tube according to claim 8, characterized in that, The terahertz traveling wave tube has three exhaust channels for vacuuming, which are respectively located at the front end of the electron gun near the anode, at the tail end of the electron gun away from the anode, and at the end of the collector away from the high-frequency interaction component.

10. The terahertz traveling wave tube according to claim 8 or 9, characterized in that, The collector is a multi-stage step-down collection structure used to recover the energy of electrons.

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