CN205542690U - Periodic permanent magnetic focusing system and speed adjusting pipe in adjustable magnetic field - Google Patents

Abstract

The utility model provides a periodic permanent magnet focusing system and a klystron that can adjust the magnetic field. The periodic permanent magnet focusing system includes an electromagnetic coil adjustment device and a periodic permanent magnet focusing device. The electromagnetic coil adjustment device includes N coils and a support shell body, the N coils are located in the accommodating cavity of the supporting shell, and the outer coil pole piece of the electromagnetic coil adjusting device is fixedly connected with one end of the periodic permanent magnet focusing device. The electromagnetic coil adjustment device of the utility model is arranged in the transition area of the klystron, so that the electron injection angle matches the periodic permanent magnetic focusing magnetic field, which overcomes the disadvantage that the magnetic field of the existing permanent magnetic focusing system cannot be adjusted or is inconvenient to adjust; the coil The current value can be adjusted separately, the magnetic field adjustment is more flexible, and the adjustment accuracy is higher; the klystron has the periodic permanent magnet focusing system, and the beam quality is high; the rear end of the periodic permanent magnet focusing device is also equipped with an electromagnetic coil adjustment device, which can be adjusted The transmission state of the electron beam can obtain a higher transmission rate of the electron beam.

Description

A periodic permanent magnet focusing system and klystron with adjustable magnetic field

technical field

The utility model relates to the technical field of vacuum electronic devices, in particular to a periodic permanent magnet focusing system and a klystron that can adjust a magnetic field.

Background technique

The klystron is a device that converts kinetic energy into high-frequency microwave energy through electron injection as a transduction medium. In the klystron, after the electron beam is emitted from the cathode, it is transmitted to the anode by the force of the electric field, and is compressed and shaped by the electric field formed by the focusing electrode, the cathode and the anode. When the electron beam diameter is compressed to a certain extent, due to the effect of space charge force, the electron beam will diverge radially. Therefore, it is necessary to take restraint measures for electronic injection. In the klystron, the function of the focusing system is to realize electron beam forming and electron beam shape retention, which has a decisive influence on obtaining high-performance electron beams.

The electrons are injected into the magnetic field where the magnetic force lines are in the same direction as their motion, and will be constrained by the magnetic field correction force, fluctuate regularly around the magnetic force lines, and transmit along the original direction. This device that generates electron beam confining magnetic field is called focusing system.

Commonly used structures for generating magnetic fields include electromagnetic focusing systems and permanent magnetic focusing systems, among which the permanent magnetic focusing system has the advantages of small size, light weight, and no power consumption. With the development of klystrons towards high-frequency bands, the periodic permanent magnet focusing method has been applied to high-frequency klystrons and has achieved success. The periodic permanent magnet focusing method can greatly reduce the volume and weight of the focusing system, and has the advantages of small stray magnetic field, simple structure and convenient use.

As shown in FIG. 1 , the periodic permanent magnet focusing system in the prior art generates a periodically reversing magnetic field in the electron beam transmission region, which generally consists of a permanent magnet 21 , an outer magnetic shield 23 and a permanent magnet pole piece 22 . The materials of the iron screen and the pole piece are all pure iron; the magnetic force lines of the focusing system are distributed along a certain route, and their magnitude is constant. The electron beam is focused on the center and near the center of the periodic permanent magnet focusing system and transported along the axial direction. The magnetic field of the periodic permanent magnet focusing system is mainly distributed in the area between the anode head and the collector pole, and the magnetic field in the transition area of the electron gun can adjust the state of the electron beam when it enters the channel, which plays a key role. The periodic permanent magnet focusing system of the above prior art has the following technical defects:

(1) After the periodic permanent magnet focusing system is formed, its magnetic field distribution is not easy to adjust. If the focusing electron injection effect is poor, the focusing system needs to be replaced;

(2) The magnetic field distribution in the transition area is related to the matching state of the electron beam and the focusing system. Generally, in the working state, a small magnetic block is pasted near the magnetic screen at the end of the electron gun to adjust the magnetic field in this area, which is difficult to adjust;

(3) Adjusting the magnetic field by pasting a magnetic sheet on the focusing system can only be used in klystrons operating at low voltage. When the operating voltage is too high, it cannot be adjusted in consideration of personal safety.

Utility model content

(1) Technical problems to be solved

In order to solve the above-mentioned problems in the prior art, the utility model provides a periodic permanent magnet focusing system and a klystron with an adjustable magnetic field.

(2) Technical solution

The utility model provides a periodic permanent magnet focusing system with an adjustable magnetic field. The periodic permanent magnet focusing system includes an electromagnetic coil adjustment device 10 and a periodic permanent magnet focusing device 20; wherein the electromagnetic coil adjustment device 10 includes N coils 11 and The support housing, the N coils 11 are located in the accommodation cavity of the support housing, the outer coil pole piece 12 of the electromagnetic coil adjustment device 10 is fixedly connected to one end of the periodic permanent magnet focusing device 20, wherein N is a natural number greater than or equal to 2 .

Preferably, the support housing includes N+1 coil pole pieces 12 and N coil magnetic shields 13; wherein, the coil pole pieces 12 and the coil magnetic shields 13 are circular disks in cross-section, and the coil pole pieces 12 The same as the outer diameter of the coil magnetic shield 13, the inner diameter of the coil pole piece 12 is smaller than the inner diameter of the coil magnetic shield 13, N+1 coil pole pieces 12 and N coil magnetic shields 13 are aligned and fixedly connected, and the outermost coil pole The inner diameter of the shoe 12 is smaller than the inner diameter of other coil pole shoes 12, and two adjacent coil pole shoes 12 and the coil magnetic shield 13 in between form the accommodating cavity of the supporting shell.

Preferably, the coil 11 generates an axial magnetic field after being energized, and under the guidance of the coil pole piece 12, the periodically placed coil 11 generates a periodic magnetic field in the transition zone, and the intensity and distribution of the magnetic field in the transition zone change with the change of the current value of the coil 11 , the electron beam matches the main magnetic field, and the trajectory of the electron beam coincides with the magnetic field line trajectory of the main magnetic field.

Preferably, the coil 11 is powered by a power supply with adjustable output power, and the current value of each coil 11 among the N coils 11 changes independently with the output power of the power supply, so as to obtain magnetic fields with different sizes and different distributions.

Preferably, the distance between two adjacent coil pole pieces 12 is equal to the length of the electron beam fluctuation cycle.

Preferably, the coil pole piece 12 and the coil magnetic shield 13 are fixedly connected by screws.

Preferably, the periodic permanent magnet focusing system further includes a second electromagnetic coil adjusting device, which has the same structure as the electromagnetic coil adjusting device 10 , and the second electromagnetic coil adjusting device is fixedly connected to the other end of the periodic permanent magnet focusing device 20 .

Preferably, the periodic permanent magnet focusing device 20 includes M permanent magnets 21 , M+1 permanent magnet pole pieces 22 and an outer magnetic shield 23 , wherein M is a natural number greater than or equal to 2.

Preferably, both the permanent magnet 21 and the permanent magnet pole piece 22 are discs with a circular cross section, the outer diameters of the permanent magnet 21 and the permanent magnet pole piece 22 are the same, and the inner diameter of the permanent magnet pole piece 22 is smaller than the inner diameter of the permanent magnet 21 , the upper and lower surfaces of the permanent magnet pole pieces 22 are respectively provided with a ring protrusion near the inner edge of the ring, so that the longitudinal section of the permanent magnet pole piece 22 presents a symmetrical "T" shape, M+1 permanent magnet pole pieces 22 and M Two permanent magnets 21 are aligned and arranged alternately, and the polarities of adjacent permanent magnets 21 are opposite. The outer magnetic shield 23 is a cylindrical structure with openings at both ends, and its length is equal to the length after the permanent magnet pole pieces 22 and the permanent magnets 21 are aligned and arranged alternately. , the inner diameter is the same as the outer diameter of the permanent magnet 21 and the permanent magnet pole shoe 22, and the inner wall of the outer magnetic shield 23 is fixedly connected with the outer wall of the permanent magnet pole shoe 22.

The utility model also provides a klystron, the area between the electron gun area and the interaction area of the klystron is a transition area, and any one of the above periodic permanent magnet focusing systems is arranged in the transition area.

(3) Beneficial effects

It can be seen from the above technical scheme that the periodic permanent magnet focusing system and klystron with adjustable magnetic field of the utility model have the following beneficial effects:

(1) The electromagnetic coil adjustment device is arranged in the transition area of the klystron, so that the electron injection angle can be matched with the periodic permanent magnet focusing magnetic field, which overcomes the disadvantage that the magnetic field of the existing permanent magnet focusing system cannot be adjusted or is inconvenient to adjust;

(2) The current value of the coil can be adjusted separately, the magnetic field adjustment is more flexible, and the magnetic field adjustment accuracy is higher;

(3) Klystron with periodic permanent magnet focusing system with adjustable magnetic field, high beam quality;

(4) The back end of the periodic permanent magnet focusing device is also equipped with an electromagnetic coil adjustment device, which can adjust the transmission state of the electron beam, and can obtain a higher transmission rate of the electron beam;

(5) The periodic permanent magnet focusing method is adopted in the interaction area, and the entire focusing system is small in size, light in weight, and consumes no power.

Description of drawings

Fig. 1 is a structural diagram of a periodic permanent magnet focusing system of the prior art;

Fig. 2 is the three-dimensional appearance diagram of the periodic permanent magnet focusing system of the adjustable magnetic field of the first embodiment of the utility model;

Fig. 3 is the longitudinal sectional view of the periodic permanent magnet focusing system of the adjustable magnetic field of the first embodiment of the utility model;

Fig. 4 is a three-dimensional semi-longitudinal sectional view of the periodic permanent magnet focusing system with adjustable magnetic field according to the first embodiment of the present invention.

【Symbol Description】

10-Electromagnetic coil adjustment device;

11-coil; 12-coil pole piece; 13-coil magnetic screen; 14-first channel;

20-period permanent magnet focusing device;

21-permanent magnet: 22-permanent magnet pole piece; 23-outer magnetic screen; 24-second channel.

detailed description

In order to make the purpose, technical solutions and advantages of the utility model clearer, the utility model will be further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

The area between the electron gun area and the interaction area of the klystron is the transition area. The transition area is a non-uniform magnetic field, which is a magnetic field dissipation area. The electron injection from the electron gun enters the interaction area after passing through the transition area. Due to the transition The existence of the region makes the electron beam not meet the ideal entrance conditions when entering the interaction region, thus affecting the beam current effect of the focusing system. The utility model officially provides a periodic permanent magnet focusing system with an adjustable magnetic field. The periodic permanent magnet focusing system with an adjustable magnetic field can adjust the magnetic field in the transition zone, so that the electrons passing through the transition zone meet the entrance conditions of the main magnetic field in the interaction zone. , to achieve the best match between the electron beam and the main magnetic field in the interaction area, thereby improving the beam current effect of the focusing system.

Please refer to Fig. 2, Fig. 3 and Fig. 4, the periodical permanent magnet focusing system of the adjustable magnetic field of the first embodiment of the utility model includes the electromagnetic coil adjustment device 10 and the periodic permanent magnet focus device 20, and the electromagnetic coil adjustment device includes N A coil 11 and a supporting shell, the N coils 11 are located in the accommodating chamber of the supporting shell; the periodic permanent magnet focusing device 20 includes M permanent magnets 21, M+1 permanent magnet pole pieces 22 and an external magnetic shield 23; Wherein, N and M are natural numbers greater than or equal to 2.

The support housing includes N+1 coil pole pieces 12 and N coil magnetic shields 13, the coil pole pieces 12 and the coil magnetic shields 13 are both discs with a circular cross section, the coil pole pieces 12 and the coil magnetic shields 13 The outer diameter is the same, the inner diameter of the coil pole piece 12 is smaller than the inner diameter of the coil magnetic shield 13, N+1 coil pole pieces 12 and N coil magnetic shields 13 are aligned and fixedly connected, and the inner diameter of the outermost coil pole piece 12 is smaller than the other The inner diameter of the coil pole pieces 12 forms a first channel 14 , and two adjacent coil pole pieces 12 and the coil magnetic shield 13 between them form an accommodating cavity of the supporting shell. In Figures 2, 3, and 4, the N is 2.

Both the permanent magnet 21 and the permanent magnet pole piece 22 are discs with a circular cross section, the outer diameters of the permanent magnet 21 and the permanent magnet pole piece 22 are the same, and the inner diameter of the permanent magnet pole piece 22 is smaller than the inner diameter of the permanent magnet 21, and the permanent magnet The upper and lower surfaces of the pole pieces 22 are each provided with a ring protrusion near the inner edge of the ring, so that the longitudinal section of the permanent magnet pole piece 22 presents a symmetrical "T" shape, M+1 permanent magnet pole pieces 22 and M permanent magnets 21 are aligned and arranged alternately to form a second channel 24. The polarities of adjacent permanent magnets 21 are opposite. The outer magnetic shield 23 is a cylindrical structure with two ends open, and its length is equal to that of the permanent magnet pole pieces 22 and the permanent magnets 21. The length after arrangement has the same inner diameter as that of the permanent magnet 21 and the outer diameter of the permanent magnet pole shoe 22 , and the inner wall of the outer magnetic shield 23 is fixedly connected with the outer wall of the permanent magnet pole shoe 22 . In Figures 3 and 4, the M is 8.

The outermost coil pole piece 12 of the electromagnetic coil adjusting device 10 is fixedly connected to one end of the periodic permanent magnet focusing device 20 , and the central axes of the first channel 14 and the second channel 24 coincide.

In the periodic permanent magnet focusing system with adjustable magnetic field of the first embodiment of the present utility model, the electromagnetic coil adjustment device 10 is arranged in the transition area, and the coil 11 generates an axial magnetic field after being energized, and is placed periodically under the guidance of the coil pole shoe 12 The coil 11 generates a periodic magnetic field in the transition zone. The strength of the magnetic field in the transition zone is proportional to the current of the coil 11 and inversely proportional to the inner diameter of the coil pole piece 12. By adjusting the current of the coil 11, the intensity and distribution of the magnetic field in the transition zone will be adjusted accordingly. change, the electron beam fluctuation state and transmission characteristics in the transition zone are adjusted, so that when the electron beam enters the main magnetic field formed by the periodic permanent magnet focusing device 20 in the interaction zone, the electron beam matches the main magnetic field, that is, the electron beam track and the main magnetic field The trajectory of the magnetic field line coincides, thereby realizing the precise adjustment of the magnetic field distribution of the periodic permanent magnet focusing system, and solving the defect that the existing permanent magnet focusing system cannot perform magnetic field adjustment and the adjustment is difficult.

Preferably, the coil 11 is powered by a power supply with adjustable output power, and the current value of the coil 11 is changed by adjusting the output power of the power supply; furthermore, the current values of the N coils 11 can be individually adjusted to obtain magnetic fields of different sizes and different distributions, The magnetic field adjustment is more flexible and the magnetic field adjustment accuracy is higher; furthermore, the coil 11 is made of copper conductor enameled wire.

Preferably, the distance between two adjacent coil pole pieces 12 (that is, the thickness of the coil magnetic shield 13 ) is equal to the length of the electron beam fluctuation period.

Preferably, the distance between two adjacent permanent magnet pole pieces 22 (i.e. the thickness of the permanent magnet 21) is equal to 1/5 of the electron injection plasma wavelength length; the permanent magnet 21 is selected from samarium cobalt material or neodymium iron boron material; the outer magnetic shield 23 select pure iron material for use.

Preferably, the coil pole piece 12 and the coil magnetic shield 13 are fixedly connected by screws, and the permanent magnet pole piece 22 and the outer magnetic shield 23 are fixedly connected by screws.

The periodic permanent magnet focusing system with adjustable magnetic field of the second embodiment of the utility model, in order to achieve the purpose of brief description, any description of the technical features in the above first embodiment that can be used for the same application is hereby, and there is no need to repeat the same description . The periodic permanent magnet focusing system with adjustable magnetic field also includes a second electromagnetic coil adjusting device, which has the same structure as the electromagnetic coil adjusting device 10 of the first embodiment, and the second electromagnetic coil adjusting device is fixed to the other end of the periodic permanent magnet focusing device 20 The connection is the same as the connection between the electromagnetic coil adjusting device 10 and the periodic permanent magnet focusing device 20 in the first embodiment.

In addition to the functions and technical effects of the first embodiment, the periodic permanent magnet focusing system with adjustable magnetic field of the second embodiment of the utility model, because the electron beam is transmitted to the rear end of the interaction area, its speed is scattered and serious, and it can also The size and distribution of the magnetic field at the rear end of the interaction region are adjusted by the second electromagnetic coil adjustment device, so that the transmission state of the electron beam is adjusted, thereby obtaining a higher transmission rate of the electron beam.

The third embodiment of the utility model provides a klystron, the region between the electron gun region and the interaction region of the klystron is a transition region, and the periodic permanent magnet focusing system of any of the above-mentioned embodiments is arranged in the transition region Area.

The periodic permanent magnetic focusing system and the klystron of the embodiment of the utility model adopt the periodic permanent magnetic focusing mode in the interaction area, and the whole focusing system has the advantages of small size, light weight, and no power consumption; at the same time, An electromagnetic coil adjustment device is installed in the transition area. By adjusting the electromagnetic coil current, the transmission state of the electron injection in the transition area can be adjusted, so that the electron injection angle can be matched with the periodic permanent magnetic focusing magnetic field, which overcomes the traditional permanent magnetic focusing system. The shortcomings of the adjustment means, the klystron of the periodical permanent magnet focusing system with adjustable magnetic field, has the advantage of high beam quality.

So far, the present embodiment has been described in detail with reference to the drawings. Based on the above description, those skilled in the art should have a clear understanding of the periodic permanent magnet focusing system and klystron of the utility model with adjustable magnetic field.

It should be noted that, in the accompanying drawings or in the text of the specification, implementations that are not shown or described are forms known to those of ordinary skill in the art, and are not described in detail. In addition, the above definition of each element is not limited to the various specific structures, shapes or methods mentioned in the embodiments, and those skilled in the art can easily modify or replace them, for example:

(1) Coil pole pieces and permanent magnet pole pieces can also be made of other commonly used materials;

(3) The directional terms mentioned in the embodiments, such as "up", "down", "front", "back", "left", "right", etc., are only referring to the directions of the drawings, and are not used to limit The scope of protection of the utility model;

(4) The above embodiments can be mixed and matched with each other or with other embodiments based on design and reliability considerations, that is, technical features in different embodiments can be freely combined to form more embodiments.

In summary, the utility model provides a periodic permanent magnet focusing system and a klystron with an adjustable magnetic field. The entire focusing system is small in size, light in weight, and does not consume power. The transmission state adjustment of the electron beam makes the electron injection angle match the periodic permanent magnet focusing magnetic field, which overcomes the disadvantage of no adjustment means after the traditional permanent magnet focusing system is formed.

The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the present utility model in detail. It should be understood that the above descriptions are only specific embodiments of the present utility model and are not intended to limit the present invention. For the utility model, any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the utility model shall be included in the protection scope of the utility model.

Claims (10)

1. a periodic permanent magnet focusing system of adjustable magnetic field, is characterized in that, this periodic permanent magnet focusing system comprises electromagnetic coil adjusting device (10) and periodic permanent magnet focusing device (20); Wherein, the electromagnetic coil adjusting device (10) includes N coils (11) and a supporting shell, and the N coils (11) are located in the accommodating chamber of the supporting shell, The outer coil pole piece (12) of the electromagnetic coil adjusting device (10) is fixedly connected to one end of the periodic permanent magnet focusing device (20), wherein N is a natural number greater than or equal to 2. 2. The periodical permanent magnet focusing system as claimed in claim 1, characterized in that, the supporting housing comprises N+1 coil pole pieces (12) and N coil magnetic shields (13); Wherein, the coil pole piece (12) and the coil magnetic shield (13) are both circular discs with a cross section, the outer diameters of the coil pole piece (12) and the coil magnetic shield (13) are the same, and the coil pole piece (12) The inner diameter of the coil magnetic shield (13) is smaller than the inner diameter of the coil magnetic shield (13), the N+1 coil pole pieces (12) and the N coil magnetic shields (13) are aligned and arranged in phases and fixedly connected, and the inner diameter of the outermost coil pole piece (12) is smaller than the other The inner diameter of the coil pole piece (12), two adjacent coil pole pieces (12) and the coil magnetic shield (13) in the middle form the accommodating cavity of the supporting shell. 3. The periodical permanent magnet focusing system as claimed in claim 2, characterized in that, the axial magnetic field is generated after the coil (11) is energized, and under the guidance of the coil pole piece (12), the periodically placed coil (11) is in transition A periodic magnetic field is generated in the zone, and the intensity and distribution of the magnetic field in the transition zone change with the change of the current value of the coil (11). The electron beam matches the main magnetic field, and the trajectory of the electron beam coincides with the magnetic force line track of the main magnetic field. 4. the periodical permanent magnet focusing system as claimed in claim 3, is characterized in that, coil (11) is powered by the power supply with adjustable output power, The current value of each coil (11) among the N coils (11) is changed independently with the change of the output power of the power supply, so as to obtain magnetic fields with different sizes and different distributions. 5. The periodical permanent magnet focusing system according to claim 2, characterized in that the distance between two adjacent coil pole pieces (12) is equal to the length of the electron beam fluctuation period. 6. The periodic permanent magnet focusing system according to claim 2, characterized in that the coil pole piece (12) and the coil magnetic shield (13) are fixedly connected by screws. 7. The periodical permanent magnet focusing system as claimed in claim 1, characterized in that, the periodical permanent magnet focusing system also comprises a second electromagnetic coil adjusting device, which has the same structure as the electromagnetic coil adjusting device (10), and the second electromagnetic coil The coil adjusting device is fixedly connected with the other end of the periodic permanent magnet focusing device (20). 8. The periodic permanent magnet focusing system as claimed in claim 1, characterized in that, the periodic permanent magnet focusing device (20) comprises M permanent magnets (21), M+1 permanent magnet pole pieces (22) and external magnetic Screen (23), wherein M is a natural number greater than or equal to 2. 9. The periodical permanent magnet focusing system as claimed in claim 8, is characterized in that, permanent magnet (21) and permanent magnet pole piece (22) all are the disc that cross section is annulus, permanent magnet (21) and permanent magnet The outer diameters of the magnet pole pieces (22) are the same, the inner diameter of the permanent magnet pole pieces (22) is smaller than the inner diameter of the permanent magnets (21), and the upper and lower surfaces of the permanent magnet pole pieces (22) are respectively provided with a ring near the inner edge of the ring. The protrusions make the longitudinal section of the permanent magnet pole piece (22) present a symmetrical "T" shape, M+1 permanent magnet pole pieces (22) and M permanent magnets (21) are aligned and arranged alternately, and the adjacent permanent magnets (21 ) is opposite in polarity, and the outer magnetic screen (23) is a cylindrical structure with openings at both ends, and its length is equal to the length after the permanent magnet pole piece (22) and the permanent magnet (21) are aligned and arranged alternately, and its inner diameter is the same as that of the permanent magnet (21) is the same as the outer diameter of the permanent magnet pole piece (22), and the outer magnetic shield (23) inner wall is fixedly connected with the outer side wall of the permanent magnet pole piece (22). 10. A klystron, characterized in that the region between the electron gun region and the interaction region of the klystron is a transition region, and the periodical permanent magnet focusing system described in any one of claims 1 to 9 is arranged at the transition zone.