阅读说明：本技术 频率可调加速装置、包括其的加速器及其调节方法 (Frequency-adjustable accelerating device, accelerator comprising frequency-adjustable accelerating device and adjusting method of frequency-adjustable accelerating device ) 是由 蓝清宏 王平 郝聪慧 牛焕焕 张博鹏 韩金刚 万知之 于 2020-12-30 设计创作，主要内容包括：本发明提供一种频率可调的加速装置,包括：加速管,配置为通过接收微波建立加速电磁场并对进入加速管的电子束进行加速；和调谐器,通过第一耦合孔与所述加速管耦接,配置为可调节所述加速管的工作频率。本发明着力解决加速管设计生产中耦合器频率漂移问题,避免反复测试修配耦合器,减少调谐时间,提高加速管成品率,提高工作效率。(The invention provides a frequency-adjustable accelerator, comprising: an acceleration tube configured to establish an acceleration electromagnetic field by receiving microwaves and accelerate electron beams entering the acceleration tube; and a tuner coupled to the acceleration tube through a first coupling hole and configured to adjust an operating frequency of the acceleration tube. The invention aims to solve the problem of frequency drift of the coupler in the design and production of the accelerating tube, avoid repeated testing and repairing of the coupler, reduce tuning time, improve the yield of the accelerating tube and improve working efficiency.)

1. A frequency tunable acceleration apparatus, comprising:

an acceleration tube configured to establish an acceleration electromagnetic field by receiving microwaves and accelerate electron beams entering the acceleration tube; and

a tuner coupled to the acceleration tube through a first coupling hole and configured to adjust an operating frequency of the acceleration tube.

2. The accelerating device of claim 1, wherein the accelerating tube comprises:

a plurality of accelerating cavities configured to establish an accelerating electromagnetic field and accelerate the electron beam, the first coupling hole being located on a cavity wall of one of the accelerating cavities; and

a coupling cavity disposed between adjacent accelerating cavities configured to couple the microwaves.

3. An acceleration arrangement according to claim 2, wherein the tuner comprises:

the tuner shell is internally provided with a resonant cavity which is communicated with one acceleration cavity of the acceleration tube through a first coupling hole;

the tuning rod enters the resonant cavity through the through hole and is configured to adjust the working frequency of the accelerating tube by adjusting the depth of the tuning rod entering the resonant cavity.

4. An accelerating device as in claim 3, wherein the tuner and the one accelerating cavity form a radial cavity chain, and the frequency of the radial cavity chain decreases as the depth of the tuning rod into the resonant cavity increases; the frequency of the radial cavity chain increases as the depth of the tuning rod into the resonant cavity becomes smaller.

5. An accelerating device as in claim 3, wherein the resonant cavity has an I-shaped structure, a spherical structure, an ellipsoidal structure or a cylindrical structure.

6. An accelerating device as set forth in claim 5, wherein the tuner housing further comprises:

the choke structure is arranged on one side of the through hole close to the resonant cavity and is configured to prevent microwave leakage; and

and the air-tight device is arranged on one side of the through hole far away from the resonant cavity and is configured to prevent air from entering the resonant cavity.

7. An accelerating device as set forth in claim 5 or 6, wherein the accelerating device includes a plurality of interchangeable tuners, each tuner being sized to correspond to a different frequency of microwaves.

8. An accelerating device as in claim 4, further comprising a waveguide system comprising:

a waveguide window configured to receive the microwaves and isolate air; and

and the waveguide is coupled between the waveguide window and the accelerating tube, communicated with the accelerating tube through a second coupling hole and configured to transmit the microwave.

9. The accelerating device as recited in claim 8, wherein the radial cavity chain further comprises the waveguide, the waveguide and the tuner are both coupled to one of the accelerating cavities of the accelerating tube, and the tuning device adjusts the frequency of the radial cavity chain to adjust the operating frequency of the accelerating tube.

10. An accelerating device as in any of claims 1-6, wherein the accelerating device comprises a plurality of tuners coupled with one or more accelerating cavities of the accelerating tube through a plurality of first coupling apertures.

11. An accelerator, comprising:

a power source configured to emit microwaves;

an electron gun configured to emit an electron beam; and

an accelerating device as in any of claims 1-10, coupled to the power source and the electron gun, configured to receive the microwaves to create an accelerating electromagnetic field, receive the electron beam and accelerate it by the accelerating electromagnetic field, wherein the operating frequency of the accelerating device is adjustable.

12. The accelerator of claim 11, wherein the electron gun is coupled to a leading chamber of the acceleration tube, the accelerator further comprising a target structure or window structure coupled to a trailing chamber of the acceleration tube, the target structure configured to receive the electron beam accelerated by the acceleration tube and to generate X-rays, the window structure configured to extract the electron beam accelerated by the acceleration tube.

13. A method of adjusting the operating frequency of an accelerating device as set forth in any of claims 1-10, comprising: adjusting the tuner to adjust the operating frequency.

Technical Field

The invention relates to the microwave-related field, in particular to a frequency-adjustable accelerating device, an accelerator comprising the frequency-adjustable accelerating device and an adjusting method of the frequency-adjustable accelerating device.

Background

The accelerator is widely applied to the fields of medical radiotherapy, industrial nondestructive testing, radiation imaging and the like as an X-ray source, and comprises an electron gun, a modulator, a power source, a microwave transmission system, an accelerating tube, a focusing system, a vacuum system and the like, wherein the accelerating tube is one of the core components of the accelerator.

Basic operating principle of the accelerator: the modulator generates a high-voltage pulse and a delay pulse, the high-voltage pulse excites the power source, the output high-power radio-frequency pulse enters the accelerating tube through the microwave transmission system, and a radio-frequency accelerating electromagnetic field is established; and the other delay pulse is provided for the electron gun, an electron beam is extracted and injected into the accelerating tube, and the accelerating tube is accelerated by the accelerating electromagnetic field, so that a high-energy electron beam is generated or the electron beam strikes a heavy metal target to generate X rays.

External power is fed into the accelerating tube through a coupling hole of a coupler, the coupler is a special and key cavity type in the accelerating tube, as shown in fig. 1, the coupler is laterally opened on the basis of an accelerating cavity and is connected with a waveguide, and the frequency drift of the cavity is inevitably caused by the opening of the accelerating cavity. The stable operation of the accelerating tube requires that the resonant frequencies of various cavity types (an accelerating cavity, a coupler and a coupling cavity) forming the accelerating tube need to be kept consistent, and ensuring the frequency consistency of various cavity types is a big difficulty in the design and production of the accelerating tube, which puts high requirements on the accuracy of the simulation of the accelerating tube and the reliability of the processing technology.

The standard for whether the resonant frequency reaches the consistency is to measure the field distribution curve of the accelerating tube, the qualified accelerating tube should have an electric field in the accelerating cavity, the magnitude of the electric field in the coupling cavity is very small, and the magnitude of the electric field is basically lower than that of the electric field of 5% of the accelerating cavity.

Generally, in order to ensure that the working frequency of the coupler is at the resonance frequency, generally, when coupler parts are machined, process production parameters reach simulation design values, which have very high requirements on the simulation accuracy and the reliability of the machining process; another method is to leave a certain margin for the critical dimension (such as dimension D shown in fig. 1) affecting the coupler frequency during processing, and make the coupler resonant frequency consistent with the resonant frequency of the rest cavity chains by repeated test and repair.

The existing method for ensuring the resonant frequency of the coupler has very high requirements on simulation accuracy and reliability of a machining process on one hand, and the method for repairing and assembling for many times can increase time cost and machining cost and has low efficiency on the other hand.

It is also worth noting that after tuning is completed in the process of producing the accelerating tube, the whole tube needs to be subjected to a process flow of high-temperature (550 ℃) welding and annealing to remove stress and gas impurities, which causes the accelerating tube to generate a certain degree of plastic deformation, so that the problem that the cavity frequencies of the accelerating tube are inconsistent occurs, but the accelerating tube is welded into the whole tube and cannot be repaired to the critical dimension.

Once the resonance failure occurs, a certain degree of electric field occurs in the coupling cavity, and the electric field acts to decelerate the particles.

At this time, the design target (certain energy and dose rate) of the accelerating tube is required to be achieved, and only a method of sacrificing the power of the power source is available, but the improvement of the peak power of the power source is a technical problem in the market of the domestic power source.

The statements in this background section merely represent techniques known to the public and are not, of course, representative of the prior art.

Disclosure of Invention

In view of at least one of the defects in the prior art, the present invention provides a frequency-adjustable accelerator apparatus, which can solve the problem of frequency inconsistency between a coupler and an adjacent accelerator cavity caused by coupler frequency drift in design and production of an accelerator tube, and aims to provide a flexible and adjustable design scheme for design and production of an accelerator tube, reduce production cost and reduce sacrifice of power source power. .

The invention provides a frequency-adjustable accelerator, comprising: an acceleration tube configured to establish an acceleration electromagnetic field by receiving microwaves and accelerate electron beams entering the acceleration tube; and a tuner coupled to the acceleration tube through a first coupling hole and configured to adjust an operating frequency of the acceleration tube.

According to an aspect of the present invention, wherein the acceleration pipe comprises: a plurality of accelerating cavities configured to establish an accelerating electromagnetic field and accelerate the electron beam, the first coupling hole being located on a cavity wall of one of the accelerating cavities; and a coupling cavity disposed between adjacent accelerating cavities, configured to couple the microwaves.

According to an aspect of the invention, wherein the tuner comprises: the tuner shell is internally provided with a resonant cavity which is communicated with one acceleration cavity of the acceleration tube through a first coupling hole; the tuning rod enters the resonant cavity through the through hole and is configured to adjust the working frequency of the accelerating tube by adjusting the depth of the tuning rod entering the resonant cavity.

According to an aspect of the present invention, the tuner and the one of the acceleration cavities form a radial cavity chain, and when the depth of the tuning rod entering the resonant cavity becomes larger, the frequency of the radial cavity chain is reduced; the frequency of the radial cavity chain increases as the depth of the tuning rod into the resonant cavity becomes smaller.

According to an aspect of the invention, wherein the resonant cavity has an i-shaped structure, a spherical structure, an ellipsoidal structure or a cylindrical structure.

According to an aspect of the invention, wherein the tuner housing further comprises: the choke structure is arranged on one side of the through hole close to the resonant cavity and is configured to prevent microwave leakage; and the air-tight device is arranged on one side of the through hole far away from the resonant cavity and is configured to prevent air from entering the resonant cavity.

According to one aspect of the invention, wherein the accelerating means comprises a plurality of interchangeable tuners, each tuner being dimensioned for microwaves of a different frequency.

According to one aspect of the invention, the accelerating device further comprises a waveguide system comprising: a waveguide window configured to receive the microwaves and isolate air; and a waveguide coupled between the waveguide window and the acceleration tube, communicating with the acceleration tube through a second coupling hole, and configured to transmit the microwave.

According to an aspect of the present invention, the radial cavity chain further includes the waveguide, the waveguide and the tuner are both coupled to one of the accelerating cavities of the accelerating tube, and the tuner is used to adjust the frequency of the radial cavity chain, so as to achieve the adjustable operating frequency of the accelerating tube.

According to an aspect of the present invention, wherein the accelerating means comprises a plurality of tuners coupled with the one or more accelerating cavities of the accelerating tube through a plurality of first coupling holes.

The present invention also provides an accelerator comprising: a power source configured to emit microwaves; an electron gun configured to emit an electron beam; and an accelerating device as in any of claims 1-10, coupled to the power source and the electron gun, configured to receive the microwaves to create an accelerating electromagnetic field, receive the electron beam and accelerate it by the accelerating electromagnetic field, wherein the operating frequency of the accelerating device is adjustable.

According to an aspect of the invention, wherein the electron gun is coupled to a leading chamber of the acceleration tube, the accelerator further comprises a target structure or a window structure coupled to a trailing chamber of the acceleration tube, the target structure being configured to receive the electron beam accelerated by the acceleration tube and to generate X-rays, the window structure being configured to extract the electron beam accelerated by the acceleration tube.

The present invention also provides a method of adjusting the operating frequency of an accelerating device as described above, comprising: adjusting the tuner to adjust the operating frequency.

The features and advantages described in the specification are not all inclusive and, in particular, many additional features and advantages will be apparent to one of ordinary skill in the art in view of the drawings and specification. Moreover, it should be noted that the terminology used in the description has been chosen primarily for readability and instructional purposes, and may not have been chosen to delineate or circumscribe the inventive subject matter.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure and are not to limit the disclosure. In the drawings:

FIG. 1 shows a three-dimensional mechanical cross-sectional view of an accelerating tube and waveguide;

FIG. 2A shows an oblique view of a three-dimensional mechanical model of an acceleration device of one embodiment of the present invention;

FIG. 2B shows a front cross-sectional view of the three-dimensional mechanical model of FIG. 2A;

FIG. 3A shows a front cross-sectional view of a tuner;

FIG. 3B shows an oblique cross-sectional view of the tuner;

FIG. 3C shows a top view of the tuner;

FIG. 3D shows a 3D model schematic of a tuner;

FIG. 4 is a schematic diagram showing the depth of insertion of the tuning rod of the tuner into the resonant cavity versus the axial cavity chain frequency variation;

FIG. 5A shows a simulation of an accelerator device without an attached waveguide according to one embodiment of the invention;

FIG. 5B shows a simulation of an accelerating device for an open-coupled-aperture-connected waveguide according to an embodiment of the present invention;

FIG. 5C is a simulation of an acceleration device after adjustment of a tuning rod in accordance with an embodiment of the present invention; and

figure 6 shows a schematic of an accelerator of the invention.

Detailed Description

In the following, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the description of the present invention, it should be noted that unless otherwise explicitly stated or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection, either mechanically, electrically, or in communication with each other; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly above and obliquely above the second feature, or simply meaning that the first feature is at a lesser level than the second feature.

The following disclosure provides many different embodiments or examples for implementing different features of the invention. To simplify the disclosure of the present invention, the components and arrangements of specific examples are described below. Of course, they are merely examples and are not intended to limit the present invention. Furthermore, the present invention may repeat reference numerals and/or letters in the various examples, such repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. In addition, the present invention provides examples of various specific processes and materials, but one of ordinary skill in the art may recognize applications of other processes and/or uses of other materials.

The invention designs an accelerating device externally connected with a tuner outside an accelerating tube, which adjusts the working frequency of the accelerating tube by adjusting the tuner. The design method aims to solve the problem that the frequency of the coupler is inconsistent with that of an adjacent accelerating cavity due to the frequency drift of the coupler in the design and production of the accelerating tube, and aims to provide a flexible and adjustable design scheme for the design and production of the accelerating tube, reduce the production cost and reduce the sacrifice of power source power.

The preferred embodiments of the present invention will be described in conjunction with the accompanying drawings, and it will be understood that they are described herein for the purpose of illustration and explanation and not limitation.

The present invention provides a frequency-tunable accelerating device 100, as shown in fig. 2A, comprising an accelerating tube 1001 and a tuner 1002, wherein the accelerating tube 1001 establishes an accelerating electromagnetic field by receiving microwaves and accelerates electron beams entering the accelerating tube 1001; the tuner 1002 is coupled to the acceleration tube 1001 through a first coupling hole H1 (see fig. 2B), and is configured to adjust an operating frequency of the acceleration tube 1001.

As shown in fig. 2B, the accelerating tube 1001 includes a plurality of accelerating cavities 1001-1, a plurality of coupling cavities 1001-2, and a coupler 1001-3. The accelerating cavity 1001-1 is configured to establish an accelerating electromagnetic field and accelerate an electron beam, the coupling cavity 1001-2 is configured to couple microwaves, the coupler 1001-3 is one of the accelerating cavities, external power is fed into the accelerating tube 1001 through the coupler 1001-3 to generate the accelerating electromagnetic field, and the first coupling hole H1 is located on the coupler 1001-3 as a lateral opening hole.

Fig. 3A shows a front cross-sectional view of a tuner 1002 according to one embodiment of the present invention, tuner 1002 comprising a tuner housing 1002-1, a resonant cavity 1002-2 and a tuning rod 1002-3. The tuner housing 1002-1 is internally provided with a resonant cavity 1002-2, and the resonant cavity 1002-2 is communicated with a coupler 1001-3 of an accelerating tube 1001 through a first coupling hole H1; tuning rod 1002-3, which enters resonating cavity 1002-2 through a through hole, is configured such that the operating frequency of accelerometer 1001 can be adjusted by adjusting the depth at which tuning rod 1002-3 enters resonating cavity 1002-2.

Specifically, in the axial direction of the accelerating tube 1001, the cavity types together form an axial cavity chain, and adjusting the frequency of the axial cavity chain is to adjust the operating frequency of the accelerating tube 1001. A resonant cavity 1002-2 and a coupler 1001-3 in the tuner 1002 form a radial cavity chain, and when the depth of the tuning rod 1002-3 entering the resonant cavity 1002-2 becomes larger, the frequency of the radial cavity chain is reduced; as the depth of tuning rod 1002-3 into resonant cavity 1002-2 decreases, the frequency of the radial cavity chain increases. Adjusting the frequency of the radial cavity chain can indirectly adjust the frequency of the axial cavity chain, i.e., adjust the operating frequency of the accelerating tube 1001.

As shown in fig. 3A, a front cross-sectional view of the cavity 1002-2 of the tuner 1002 is an i-shaped structure, and for an S-band (a resonant frequency of 2998MHz), the size of the tuner 1002 is such that the outer diameter D1 of the cavity 1002-2 is Φ 46.58mm, the inner diameter D2 is Φ 20mm, the depth L is 10mm, and a through hole D3 is Φ 5mm is formed in the middle to match with the metal tuning rod 1002-3 of Φ 5. Fig. 3B shows an oblique cross-sectional view of tuner 1002.

Fig. 3C shows a top view of the tuner, and fig. 3D shows a 3D model of the tuner. As shown, cavity 1002-2 of tuner 1002 communicates with coupler 1001-3 through a first coupling hole H1, preferably first coupling hole H1 is an oblong hole with a dimension L1 × L2 × 30mm × 9mm, and a three-dimensional mechanical model of the assembly with acceleration tube 1001 is shown in fig. 2B. The first coupling hole may take other shapes as well, and needs to be sized by simulation results.

According to a preferred embodiment of the present invention, the resonant cavity 1002-2 may also have a spherical structure, an ellipsoidal structure, or a cylindrical structure.

The dimensions of tuner 1002 for one embodiment of the S band are described above, and accordingly, for the C band (5712MHz), the X band (9300MHz), the corresponding mechanical dimensions are also applicable. According to a preferred embodiment of the present invention, the acceleration device 100 may comprise a plurality of replaceable tuners 1002, each tuner 1002 is sized to correspond to microwaves of different frequencies, each tuner may perform a frequency adjustment function, and different tuners 1002 may be replaced according to actual frequency requirements.

According to a preferred embodiment of the present invention, tuner housing 1002-1 further comprises a choke structure and an airtight means, not shown in the figure. The choke structure is arranged on one side of the through hole close to the resonant cavity 1002-2 and is configured to prevent microwave leakage; and an air-tight device disposed on a side of the through hole remote from the cavity 1002-2 and configured to prevent air from entering the cavity 1002-2. It will be appreciated by those skilled in the art that the choke structure and the air-tight device may take other forms, as long as the prevention of the leakage of the microwave and the prevention of the air entry are achieved, and are within the scope of the present invention.

According to a preferred embodiment of the present invention, as shown in FIG. 2A, the accelerating device 100 further comprises a waveguide system 1003, as shown in FIG. 2B, the waveguide system 1003 comprising a waveguide window 1003-1 and a waveguide 1003-2. Wherein the waveguide window 1003-1 is configured to receive microwaves and isolate air; the waveguide 1003-2 is coupled between the waveguide window 1003-1 and the acceleration tube 1001, communicates with the coupler 1001-3 of the acceleration tube 1001 through the second coupling hole H2, and is configured to transmit microwaves. The opening of the coupler tends to cause frequency drift of the cavity, which is also a problem to be solved by an embodiment of the present invention.

When the accelerating tube 1001 is communicated with the waveguide 1003-2, the radial cavity chain comprises a resonant cavity 1002-2, a coupler 1001-3 and a waveguide 1003-2, the resonant cavity 1002-2 and the waveguide 1003-2 are both coupled with the coupler 1001-3, and the frequency of the radial cavity chain, namely the frequency of the axial cavity chain, can be adjusted by adjusting the depth of the tuning rod 1002-3 entering the resonant cavity 1002-2, so that the adjustment of the working frequency of the accelerating tube 1001 is realized. Through the scheme of this embodiment, can solve the frequency drift problem that brings after the coupler trompil, avoid retesting repeatedly and repair the coupler, reduce tuning time, improve accelerating tube yield.

In order to increase the range of adjusting frequencies according to a preferred embodiment of the present invention, the acceleration device 100 may further include a plurality of tuners 1002, and the plurality of tuners 1002 are coupled with the coupler 1001-3 of the acceleration pipe 1001 through a plurality of first coupling holes H1. Further, multiple tuners 1002 may also be coupled to one or more booster cavities 1001-1, as needed to adjust the frequency of other booster cavities 1001-1.

The structure of the acceleration device 100 is described above. The rationality and feasibility of the acceleration device 100 are verified by the simulation results below.

Simulation experiments show that the degree of influence of the insertion depth of the tuning rod 1002-3 on the axial cavity chain frequency of the accelerating tube 1001 is shown in fig. 4, in which 5 marked points are respectively corresponding to a group of values with the abscissa as the length and the ordinate as the frequency, and the relationship between the depth and the frequency is shown, so that it can be seen that the tolerance of frequency adjustability is objective, and about 5 wire changes can cause 12MHz frequency changes.

In practice, tuning rods 1002-3 of different lengths may be machined to match the length required for tuning.

One embodiment of the present invention is based on simulation verification, and a simulation experiment is performed based on the accelerating device 100 of fig. 2, and the simulation results are shown in fig. 5A, 5B and 5C as the field distribution diagram and the air cavity model diagram.

Fig. 5A is a simulation diagram of the accelerating device 100 when the accelerating tube 1001 is not provided with the second coupling hole H2 to connect the waveguide 1003-2, and the accelerating device 100 includes the accelerating tube 1001 and the tuner 1002. Wherein, the right figure is an air cavity model figure; the left graph is a field distribution graph, and the height of the curve represents the strength degree of an electric field. It can be seen that in the case of resonant coupling of the cavities, the field in the coupling cavity 1001-2 is much smaller relative to the field in the accelerating cavity 1001-1, which is required for the practical operation of the accelerating tube 1001, i.e. the smaller or non-existent electric field in the coupling cavity 1001-2, the stronger the energy the accelerating cavity 1001-1 applies to the electron beam.

Fig. 5B is a diagram showing the right view of the air cavity model after the waveguide 1003-2 is openly connected to the coupler 1001-3 at the position of the second coupling hole H2 on the basis of fig. 5A, and the accelerating device 100 comprises an accelerating tube 1001, a tuner 1002 and the waveguide 1003-2. At this time, the coupler 1001-3 shifts in frequency, and the frequency of the axial cavity chain is inconsistent, and as shown in the left diagram, the electric field in the coupling cavity 1001-2 becomes stronger (see the waveform in the dashed circle), and accordingly, the energy obtained by the electron beam becomes smaller.

FIG. 5C is the addition of a tuning rod 1002-3 to the cavity shown in FIG. 5B, wherein the cavity model is shown on the right, and the cavity 1002-2 is enlarged to show a protrusion on the left side of the waist of the I-shape, which is used to simulate the volume change of the cavity caused by the insertion of the tuning rod 1002-3 into the cavity 1002-2. It can be seen from simulation that increasing the length of 1mm and the diameter of 5mm of air cylinder (the value is for the S-band) can reduce the electric field in the coupling cavity 1001-2, and the electric field recovery in the accelerating cavity 1001-1 is consistent with the 5A diagram, which shows that the frequency drift of the coupler 1001-3 can be compensated in the tuner 1002 by changing the depth of the tuning rod 1002-3 inserted into the resonant cavity 1002-2.

It should be noted that, if the electric field of the coupling cavity 1001-2 in fig. 5B is increased due to the frequency drift of the coupler 1001-3 after the accelerator apparatus 100 is welded into a whole tube, the electric field of the coupling cavity 1001-2 cannot be adjusted actually, and only by sacrificing the precious power of the power source, the accelerator tube 1001 can be classified as a failed tube in the case that the power of the power source cannot be satisfied. After the tuner designed by the invention is installed, even if the accelerating tube 1001 is welded into a whole tube, the tuning can be performed again, so that the accelerating tube 1001 reaches a design value (certain energy and dosage) under the condition that the power of an original power source is not changed, namely the yield of the accelerating tube is improved.

Therefore, the accuracy and the practicability of the embodiment of the invention are verified through the simulation result.

The present invention also provides an accelerator 10, as shown in fig. 6, including:

a power source 101 configured to emit microwaves;

an electron gun 102 configured to emit an electron beam; and

the accelerating device 100 as described above, the accelerating device 100 coupled to the power source 101 and the electron gun 102, configured to receive the microwaves to establish an accelerating electromagnetic field, receive the electron beam and accelerate it by the accelerating electromagnetic field, wherein the operating frequency of the accelerating device 100 is adjustable.

According to a preferred embodiment of the present invention, wherein the electron gun 102 is coupled to the front cavity of the accelerating tube 1001, the accelerator 10 further comprises a target structure or window structure 103 coupled to the rear cavity of the accelerating tube 1001, said target structure being configured to receive the electron beam accelerated by the accelerating tube 1001 and to generate X-rays, said window structure being configured to extract the electron beam accelerated by the accelerating tube 1001.

The present invention also provides a method of adjusting the operating frequency of the acceleration device 100 as described above, comprising: the tuner 1002 is adjusted to adjust the operating frequency.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.