Simple measuring device for electron beam track parameters of traveling wave tube

Abstract

The invention provides a simple measurement device for electron beam trajectory parameters of a traveling wave tube, belongs to the technical field of electron beam measurement, and solves the problems that an electron beam analyzer is used for measurement in the prior art, the use is relatively complex, the price is high, and the traveling wave tube is inconvenient to develop. The device comprises a base, a mounting cylinder is arranged on the base, a traveling wave tube is mounted on the mounting cylinder, corrugated pipes sleeve the outer side of the mounting cylinder at intervals, one end of each corrugated pipe is connected with the base, the other end of each corrugated pipe is connected with a sealing cover, a collector is arranged on the sealing cover, and the sealing cover is connected with an adjusting mechanism. The position of the collector is adjusted by the adjusting mechanism, so that the radial distance and the axial distance between the collector and the traveling wave tube are changed, the current density of different points in an electron beam is measured, and other track parameters are obtained; the measuring device is simple and convenient in structure and easy to operate, is an effective tool for developing a new traveling wave tube, and is also suitable for characteristic testing of various electron guns of other vacuum devices.

Description

Technical Field

[0001] The invention belongs to the technical field of electron beam measurement, in particular to a simple measurement device for traveling wave tube electron beam trajectory parameters. Background Art

[0002] A traveling wave tube (TWT) is a vacuum electronic device that amplifies microwave signals by continuously modulating the velocity of an electron beam. Electrons generated by an electron gun enter a high-frequency circuit, interacting with the axial field. This transfers the electrons' energy to the high-frequency field, amplifying the microwave signal. This device is widely used in radar, electronic countermeasures, and communications.

[0003] The electron beam trajectory parameters of a traveling wave tube (TWT) include range, beam waist radius, angle of incidence, and permeance. These parameters have a significant impact on TWT performance. The state of the electron beam significantly influences interactions and subsequent electron recovery, potentially reducing the tube's overall efficiency. While theoretical calculations and computer simulations can yield excellent TWT designs, practical factors such as thermal muzzle velocity, emission non-uniformity, and cathode surface roughness make it impossible for a TWT's electron gun to produce an ideal electron beam. Important trajectory parameters such as current density, beam waist radius, and range can differ significantly from theoretical results. Actual measurement and analysis of these parameters would allow optimization of the electron gun and magnetic system design, distinguishing between design and assembly process issues, and ultimately improving the electron beam pass rate. Prior art measurement of trajectory parameters typically requires specialized electron beam analyzers, which are complex and expensive to use, making them extremely inconvenient for practical TWT development. Summary of the Invention

[0004] In response to the above problems, the present invention aims to provide a simple device for measuring the trajectory parameters of a traveling wave tube electron beam. An adjustment mechanism is provided to adjust the position of the collector, so that the radial and axial distances between the collector and the traveling wave tube change, thereby measuring the current density at different points in the electron beam and obtaining other trajectory parameters. The measuring device of the present application has a simple structure and is easy to operate. It is an effective tool for developing new traveling wave tubes and is also suitable for characteristic testing of various electron guns of other vacuum devices.

[0005] The technical solution adopted in the present invention is as follows: A simple device for measuring the trajectory parameters of a traveling wave tube electron beam comprises a base, a mounting tube is provided on the base, a traveling wave tube is mounted on the mounting tube, a bellows is provided on the outer spacer sleeve of the mounting tube, one end of the bellows is connected to the base, the other end of the bellows is connected to a sealing cover, a collector is provided on the sealing cover, and the sealing cover is connected to an adjustment mechanism for adjusting the radial and axial distances between the collector and the traveling wave tube.

[0006] Preferably, the adjustment mechanism includes a support tube installed on the base, a first telescopic device that is telescopic along the radial direction of the support tube is installed on the support tube, the telescopic end of the first telescopic device is connected to a movable support, the movable support is provided with a second telescopic device that is telescopic along the axial direction of the support tube, the telescopic end of the second telescopic device is connected to a connecting frame, and the connecting frame is connected to the sealing cover.

[0007] Preferably, the connecting frame is connected to a connecting tube which is sleeved on the outside of the sealing cover and connected to the sealing cover, and the support tube is provided with an axial distance measuring device for measuring in conjunction with the upper end face of the connecting tube and a radial distance measuring device for measuring in conjunction with the side wall of the connecting tube.

[0008] Preferably, the base has a sealed chamber and is connected to the mounting tube, and an electrode lead post is provided on the base.

[0009] Preferably, the traveling wave tube is detachably connected to the mounting tube, the bottom of the base is detachably connected to a bottom plate for opening the sealed chamber, and the mounting tube is inserted into the sealed chamber from bottom to top and is detachably connected to the base.

[0010] Preferably, the base is connected to a suction pipe, and a suction pump is provided on the suction pipe.

[0011] Preferably, a communicating hole is provided on the mounting tube.

[0012] Preferably, the collecting electrode is detachably connected to the sealing cover.

[0013] Preferably, a collecting electrode hole is provided on the collecting electrode, and the diameter of the collecting electrode hole is 0.01 mm.

[0014] Preferably, the collecting electrode is made of copper material.

[0015] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: An adjustment mechanism is provided to adjust the position of the collector, so that the radial and axial distances between the collector and the traveling wave tube change, thereby measuring the current density at different points in the electron beam and obtaining other trajectory parameters; the measuring device of the present application has a simple structure and is easy to operate. It is an effective tool for developing new traveling wave tubes and is also suitable for characteristic testing of various electron guns of other vacuum devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 A schematic diagram of a three-dimensional structure provided by an embodiment of the present invention; Figure 2 A schematic diagram of a three-dimensional structure from another perspective provided by an embodiment of the present invention; Figure 3 A schematic cross-sectional structure diagram provided for an embodiment of the present invention.

[0018] Figure markings: 1-base; 2-support tube; 3-electrode lead column; 4-connecting tube; 5-first telescopic device; 6-movable support; 7-second telescopic device; 8-connecting frame; 9-axial distance measuring device; 10-collecting electrode; 11-sealing cover; 12-radial distance measuring device; 13-suction pipe; 14-suction pump; 15-collecting electrode hole; 16-traveling wave tube; 17-connecting hole; 18-mounting tube; 19-bellows; 20-bottom plate. DETAILED DESCRIPTION

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0021] In the description of the present invention, it should be noted that if the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the product of the application is usually placed when in use. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0022] The following combination Figure 1-Figure 3 The present invention is described in detail.

[0023] Example: A simple device for measuring the trajectory parameters of traveling wave tube electron beams, such as Figure 1 and 3As shown, it includes a base 1, a mounting tube 18 is provided on the base 1, a traveling wave tube 16 is installed on the mounting tube 18, a bellows 19 is provided on the outer spacer sleeve of the mounting tube 18, one end of the bellows 19 is connected to the base 1, and the other end of the bellows 19 is connected to a sealing cover 11, a collector 10 is provided on the sealing cover 11, and the sealing cover 11 is connected to an adjustment mechanism for adjusting the radial distance and axial distance between the collector 10 and the traveling wave tube 16.

[0024] The adjustment mechanism adjusts the position of the collector 10, causing the radial and axial distances between the collector 10 and the traveling wave tube 16 to change, thereby measuring the current density at different points in the electron beam and obtaining other trajectory parameters. Specifically, a dedicated power supply for the traveling wave tube is used to power the collector 10 and the traveling wave tube 16. The adjustment mechanism is used to move the collector 10 in the radial and axial directions, and the current at each point is directly read from the power supply. Generally speaking, the current density at the injection waist is the largest, which can be used to determine the injection waist radius and range. The current collected at each point is added together to obtain the total current, which is used to calculate the conductance coefficient of the traveling wave tube's electron gun.

[0025] The measuring device of the present application has a simple structure and is easy to operate. It is an effective tool for developing new traveling wave tubes and is also suitable for characteristic testing of various electron guns of other vacuum devices.

[0026] The bellows 19 and the sealing cover 11 can always keep the space between the collector 10 and the traveling wave tube 16 in a vacuum state during the process of adjusting the position of the collector 10, thereby ensuring that the electron gun works stably and efficiently.

[0027] The adjustment mechanism includes a support tube 2 mounted on a base 1, on which a first telescopic device 5 is mounted that is telescopically telescopic along the support tube 2, the telescopic end of the first telescopic device 5 is connected to a movable support 6, the movable support 6 is provided with a second telescopic device 7 that is telescopically telescopic along the support tube 2, the telescopic end of the second telescopic device 7 is connected to a connecting frame 8, and the connecting frame 8 is connected to the sealing cover 11. The first telescopic device 5 drives the movable support 6 and the second telescopic device 7 to move radially, and the second telescopic device 7 then drives the connecting frame 8 and the sealing cover 11 to move axially, thereby adjusting the radial and axial positions of the collector 10 on the sealing cover 11; the maximum moving length of the first telescopic device 5 is 10 mm, with an error of no more than 0.01 mm; the moving length of the second telescopic device 7 is within 50 mm, with an error of no more than 0.1 mm. The maximum moving length of the first telescopic device 5 and the second telescopic device 7 depends on the allowable displacement distance of the bellows 19. Bellows 19 with different performance can be replaced according to needs to adjust the maximum moving length of the first telescopic device 5 and the second telescopic device 7.

[0028] The first telescopic device 5 and the second telescopic device 7 can also be replaced with other linearly movable mechanisms, such as a screw-driven slide. The movable support 6 can slide with the upper end surface of the support tube 2 via a slide rail, and the connecting frame 8 can slide with the movable support 6 via the slide rail, thereby increasing the stability of movement.

[0029] The connecting frame 8 is connected to a connecting tube 4 that is sleeved on the outside of the sealing cover 11 and connected to the sealing cover 11. The support tube 2 is provided with an axial distance measuring device 9 for measuring in conjunction with the upper end face of the connecting tube 4 and a radial distance measuring device 12 for measuring in conjunction with the side wall of the connecting tube 4. In this application, the axial distance measuring device 9 and the radial distance measuring device 12 use a micrometer to measure the distance. The axial distance measuring device 9 abuts against the upper end face of the connecting tube 4 through the measuring rod at the end, thereby measuring the axial displacement of the connecting tube 4. The radial distance measuring device 12 abuts against the side wall of the connecting tube 4 along the radial direction through the measuring rod at the end, thereby measuring the radial displacement of the connecting tube 4. The values ​​measured by the axial distance measuring device 9 and the radial distance measuring device 12 can be directly displayed on the dial provided, which is convenient for reading. The axial distance measuring device 9 and the radial distance measuring device 12 can also choose to use a laser rangefinder.

[0030] The base 1 has a sealed chamber and is connected to the mounting tube 18. The base 1 is provided with an electrode lead post 3. The electrode lead post 3 is used to seal and connect the electrode lead. The electrode lead extends from the base 1 into the mounting tube 18 and is connected to the traveling wave tube 16.

[0031] The TWT 16 is detachably connected to the mounting tube 18. A base plate 20, used to open the sealed chamber, is detachably connected to the bottom of the base 1. The mounting tube 18 is inserted upward into the sealed chamber and detachably connected to the base 1. After removing the base plate 20, the mounting tube 18 and TWT 16 can be removed. After removing the mounting tube 18, a different model of TWT 16 can be replaced, allowing measurements to be performed on different TWTs. All of these detachable connections can be made with screws.

[0032] like Figure 2 and 3 As shown, the base 1 is connected to a suction pipe 13, which is equipped with a suction pump 14. Suction pump 14 applies negative pressure to the base 1 and mounting tube 18 through suction pipe 13, maintaining a vacuum state and ensuring normal measurement. Suction pump 14 is also equipped with a vacuum monitoring sensor (not shown) to ensure the vacuum state within the chamber.

[0033] A connecting hole 17 is provided on the mounting tube 18, through which the electrode lead can pass through the mounting tube 18 and be connected to the collector 10. The connecting hole 17 can also connect the inside and outside of the mounting tube 18, so that the space where the collector 10 is located is also kept in a vacuum state.

[0034] The collector 10 is detachably connected to the sealing cover 11. Due to repeated measurements, repeated bombardment of the electron beam has a damaging effect, and the collector 10 needs to be designed to be replaced as soon as it is damaged. Therefore, the collector 10 is detachably connected to the sealing cover 11, and the detachable connection can be connected by threads or screws.

[0035] The collector 10 is provided with a collector hole 15, and the diameter of the collector hole 15 is 0.01 mm. The smaller the diameter, the higher the accuracy of the measured current density, but more cross-sectional nodes need to be scanned, and the higher the scanning interval, the longer the measurement time. The diameter of the traveling wave tube electron beam itself is different, and the hole diameter should be determined based on theoretical simulation to ensure measurement accuracy while reducing measurement time. In this application, the diameter of the collector hole 15 is set to 0.01 mm as the best choice.

[0036] In this application, the collector 10 is made of copper, a material with high thermal conductivity. This material effectively collects incoming electrons and reduces secondary electrons, enabling a rapid response after receiving a pulsed electron beam. This high thermal conductivity also allows for rapid heat conduction, preventing excessive heat buildup during measurement that could affect the device's performance. A water-cooled metal plate coated with thermal grease can also be installed on the collector 10 to dissipate heat.

[0037] Furthermore, because the electron transit time is only a few nanoseconds, and a microsecond pulse contains thousands of transit cycles, the cathode emits stably within a pulse of a certain width, and a single pulse of electrons is sufficient to represent a true continuous electron beam. Using the pulse mode of the power supply effectively solves the heat dissipation problem caused by continuous electron bombardment of the collector.

[0038] Only when the collector aperture 15's diameter and displacement step size are appropriately configured can a realistic electron beam density distribution be obtained, thereby determining the electron beam waist and range parameters. Obtaining this information allows for optimal selection of the electron beam and helix inner diameter, while also enabling more accurate determination of the position and magnetic flux density of the first periodic permanent magnet, ensuring extremely high flux efficiency throughout the tube. Electrons passing through the interaction region are able to more fully exchange energy with the high-frequency field, resulting in lower energy upon reaching the collector region (of the traveling wave tube), reducing heat loss in the collector and improving overall tube efficiency.

[0039] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A simple measuring device for the trajectory parameters of a traveling wave tube electron beam, comprising a base (1), characterized in that: The base (1) is provided with a mounting tube (18), a traveling wave tube (16) is mounted on the mounting tube (18), an outer spacer sleeve of the mounting tube (18) is provided with a bellows (19), one end of the bellows (19) is connected to the base (1), and the other end of the bellows (19) is connected to a sealing cover (11), a collecting electrode (10) is provided on the sealing cover (11), and the sealing cover (11) is connected to an adjustment mechanism for adjusting the radial distance and the axial distance between the collecting electrode (10) and the traveling wave tube (16).

2. A simple measuring device for traveling wave tube electron beam trajectory parameters according to claim 1, characterized in that: The adjustment mechanism comprises a support tube (2) mounted on a base (1); a first telescopic device (5) is mounted on the support tube (2) and is telescopically telescopic along the support tube (2); a telescopic end of the first telescopic device (5) is connected to a movable support (6); a second telescopic device (7) is provided on the movable support (6) and is telescopically telescopic along the support tube (2); a telescopic end of the second telescopic device (7) is connected to a connecting frame (8); and the connecting frame (8) is connected to a sealing cover (11).

3. A simple measuring device for traveling wave tube electron beam trajectory parameters according to claim 2, characterized in that: The connecting frame (8) is connected to a connecting cylinder (4) sleeved on the outside of the sealing cover (11) and connected to the sealing cover (11); the supporting cylinder (2) is provided with an axial distance measuring device (9) for cooperating with the upper end surface of the connecting cylinder (4) for measurement, and a radial distance measuring device (12) for cooperating with the side wall of the connecting cylinder (4) for measurement.

4. The simple measuring device for the trajectory parameters of a traveling wave tube electron beam according to claim 1, characterized in that: The base (1) has a sealed chamber and is in communication with the mounting cylinder (18); an electrode lead post (3) is provided on the base (1).

5. The simple measuring device for the trajectory parameters of a traveling wave tube electron beam according to claim 4, characterized in that: The traveling wave tube (16) is detachably connected to the mounting tube (18); the bottom of the base (1) is detachably connected to a bottom plate (20) for opening the sealed chamber; the mounting tube (18) is inserted into the sealed chamber from bottom to top and is detachably connected to the base (1).

6. A simple measuring device for traveling wave tube electron beam trajectory parameters according to claim 4, characterized in that: The base (1) is connected to a suction pipe (13), and a suction pump (14) is provided on the suction pipe (13).

7. The simple measuring device for the trajectory parameters of a traveling wave tube electron beam according to claim 1, characterized in that: The mounting cylinder (18) is provided with a communication hole (17).

8. The simple measuring device for the trajectory parameters of a traveling wave tube electron beam according to claim 1, characterized in that: The collecting electrode (10) is detachably connected to the sealing cover (11).

9. The simple measuring device for the trajectory parameters of a traveling wave tube electron beam according to claim 1, characterized in that: The collecting electrode (10) is provided with a collecting electrode hole (15), and the diameter of the collecting electrode hole (15) is 0.01 mm.

10. The simple measuring device for the trajectory parameters of a traveling wave tube electron beam according to claim 1, characterized in that: The collecting electrode (10) is made of copper material.

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