CN111901957A - Hybrid acceleration structure type electron linear accelerator - Google Patents

Abstract

The invention discloses a mixed acceleration structure type electron linear accelerator, which comprises two types of acceleration structures, namely a standing wave acceleration structure and a traveling wave acceleration structure, wherein the standing wave acceleration structure is connected to the front end of the traveling wave acceleration structure, a coupling structure is arranged between a tail cavity of the standing wave acceleration structure and a head cavity of the traveling wave acceleration structure, and a power feed-in port of an acceleration tube is arranged on the traveling wave acceleration structure.

Description

A Hybrid Acceleration Structure Electron Linear Accelerator

technical field

The invention belongs to the technical field of electron linear accelerators, and in particular relates to a hybrid acceleration structure type electron linear accelerator.

Background technique

Electron linear accelerators are currently widely used in medical treatment, non-destructive testing, security inspection and irradiation fields, such as radiation therapy, industrial flaw detection, agricultural irradiation and breeding, food irradiation processing, medical disinfection, etc., creating a huge economy for human daily life. benefits and social benefits.

At present, there are mainly two types of low-energy electron linear accelerators: traveling wave accelerators and standing wave accelerators. Among them, the traveling wave accelerator is traveling wave acceleration, and the common mode is 2π/3 mode, which has the characteristics of high efficiency and stable performance. The whole machine needs to use an external focusing system, but no isolator is required; It is π/2 mode or π mode, and has the characteristics of self-focusing, high shunt impedance, high acceleration gradient, and compact structure. The whole machine needs an isolator, but no external focusing system is required.

Existing traveling wave electron accelerators are generally used in industrial fields and irradiation fields, and can generate high-power electron beams or high-dose rate X-rays by utilizing the high-efficiency characteristics of traveling-wave accelerators. Compared with the standing wave accelerator system, the traveling wave accelerator system includes a focusing system, which is mainly used in the beamforming section of the accelerating tube to ensure that the electron beam is radially focused during beamforming, and the electrons do not need an external magnetic field for focusing after reaching the traveling wave acceleration section. .

During the actual use, the inventor found that these existing technologies have at least the following technical problems:

The traveling wave accelerator needs an additional focusing system to focus the electrons. The focusing system increases the radial size of the traveling wave accelerator and also increases the cost of the system.

SUMMARY OF THE INVENTION

In order to overcome the above-mentioned shortcomings, the inventor of the present invention has continuously reformed and innovated through long-term exploration attempts and repeated experiments and efforts, and proposed a hybrid acceleration structure type electron linear accelerator, which can use the standing wave acceleration structure to have With the advantages of self-focusing and traveling wave acceleration structure, high efficiency and no reflection, the accelerator can realize electron acceleration efficiently and compactly without isolator and without external magnetic field system, and also reduces the cost of the whole machine.

In order to achieve the above-mentioned purpose, the technical scheme adopted by the present invention is to provide a hybrid acceleration structure type electron linear accelerator, which includes two types of acceleration structures, namely a standing wave acceleration structure and a traveling wave acceleration structure, and the standing wave acceleration structure is connected At the front end of the traveling wave accelerating structure, there is a coupling structure between the tail cavity of the standing wave accelerating structure and the head cavity of the traveling wave accelerating structure, and the power feeding port of the accelerating tube is arranged on the traveling wave accelerating structure.

According to a hybrid acceleration structure type electron linear accelerator according to the present invention, a further preferred technical solution is: the traveling wave acceleration structure is a return wave traveling wave acceleration structure, and the working mode is 2π/3 mode or 4π/5 A transmission waveguide is connected between the end cavity of the standing wave acceleration structure and the head cavity of the traveling wave acceleration structure, and a beam drift tube is used to connect the end cavity of the standing wave acceleration structure and the beam channel in the center of the head cavity of the traveling wave acceleration structure. The power feeding port is arranged in the tail cavity of the traveling wave acceleration structure.

According to a hybrid acceleration structure type electron linear accelerator according to the present invention, a further preferred technical solution is: the transmission waveguide is a U-shaped structure, and the two ends are respectively connected to the end cavity of the standing wave acceleration structure and the head cavity of the traveling wave acceleration structure. On the side, the orientation of the power feeding port is the same.

According to a hybrid acceleration structure type electron linear accelerator according to the present invention, a further preferred technical solution is: the traveling wave acceleration structure is a return wave traveling wave acceleration structure, and the working mode is 2π/3 mode or 4π/5 The head cavity of the mode traveling wave acceleration structure is directly connected to the end cavity of the standing wave acceleration structure and shares a cavity wall, the head cavity of the traveling wave acceleration structure is connected to the absorbing load, and the power feeding port is arranged in the tail cavity of the traveling wave acceleration structure.

According to the hybrid acceleration structure type electron linear accelerator according to the present invention, a further preferred technical solution is: the traveling wave acceleration structure is a disk-load traveling wave acceleration structure with positive group velocity, and the working mode is 2π/3 mode , the head cavity of the traveling wave acceleration structure is directly connected to the end cavity of the standing wave acceleration structure and shares a cavity wall, the absorbing load is connected to the tail cavity of the traveling wave acceleration structure, and the power feeding port is arranged in the head cavity of the traveling wave acceleration structure.

According to the hybrid acceleration structure type electron linear accelerator according to the present invention, a further preferred technical solution is that the absorption load and the power feeding port are located on the same side of the cavity array.

According to a hybrid acceleration structure type electron linear accelerator according to the present invention, a further preferred technical solution is: the coupling structure is side coupling, electrical coupling or magnetic coupling.

According to the hybrid acceleration structure type electron linear accelerator according to the present invention, a further preferred technical solution is that the working mode of the standing wave acceleration cavity is π/2 mode or π mode.

According to the hybrid acceleration structure type electron linear accelerator of the present invention, a further preferred technical solution is that the inner diameter of the beam tube of the traveling wave acceleration structure is larger than the inner diameter of the fast flow tube of the standing wave acceleration structure.

According to the hybrid acceleration structure type electron linear accelerator according to the present invention, a further preferred technical solution is that an input waveguide is connected to the power feeding port.

Compared with the prior art, the technical solution of the present invention has the following advantages/beneficial effects:

Using the advantages of the self-focusing effect of the standing wave acceleration structure and the high efficiency and non-reflection of the traveling wave acceleration structure, the accelerator can achieve electron acceleration efficiently and compactly without isolator or external magnetic field system, and it also reduces the overall cost of electron acceleration. the cost of the machine.

Description of drawings

In order to explain the technical solutions of the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore do not It should be regarded as a limitation of the scope, and for those of ordinary skill in the art, other related drawings can also be obtained according to these drawings without any creative effort.

FIG. 1 is a schematic structural diagram of the embodiment 1 of a hybrid acceleration structure type electron linear accelerator of the present invention.

2 is a schematic cross-sectional structural diagram of Embodiment 1 of a hybrid acceleration structure type electron linear accelerator of the present invention.

FIG. 3 is a cross-sectional view of a structure embodiment 1 of a hybrid acceleration structure type electron linear accelerator according to the present invention.

FIG. 4 is a schematic structural diagram of the embodiment 2 of a hybrid acceleration structure type electron linear accelerator of the present invention.

5 is a schematic cross-sectional structural diagram of Embodiment 2 of a hybrid acceleration structure type electron linear accelerator of the present invention.

FIG. 6 is a cross-sectional view of the structure embodiment 2 of a hybrid acceleration structure type electron linear accelerator according to the present invention.

FIG. 7 is a schematic structural diagram of the embodiment 3 of a hybrid acceleration structure type electron linear accelerator of the present invention.

8 is a schematic cross-sectional structural diagram of Embodiment 3 of a hybrid acceleration structure type electron linear accelerator of the present invention.

FIG. 9 is a cross-sectional view of a structure embodiment 3 of a hybrid acceleration structure type electron linear accelerator according to the present invention.

The marks in the figure are: 1. Standing wave acceleration structure 101. Standing wave acceleration structure tail cavity 2. Traveling wave acceleration structure 201. Traveling wave acceleration structure head cavity 202. Traveling wave acceleration structure tail cavity 301. Waveguide coupling structure 302. Magnetic Coupling structure 303. Electrical coupling structure 4. Arc coupling hole 5. Input waveguide 6. Absorbing load 7. Common cavity wall.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. . Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention. Thus, the detailed descriptions of embodiments of the invention provided below are not intended to limit the scope of the invention as claimed, but are merely representative of selected embodiments of the invention.

It should be noted that like numerals and letters refer to like items in the following figures, so once an item is defined in one figure, it may not be further defined and explained in subsequent figures.

Example 1:

As shown in Figure 1, a hybrid acceleration structure type electron linear accelerator includes two types of acceleration structures, namely standing wave acceleration structure 1 and traveling wave acceleration structure 2. Standing wave acceleration structure 1 is connected to the traveling wave acceleration structure. At the front end of 2, there is a coupling structure between the tail cavity 101 of the standing wave acceleration structure and the head cavity 201 of the traveling wave acceleration structure, and the power feeding port of the acceleration tube is set on the traveling wave acceleration structure 1, and the power feeding port of the acceleration tube is in the row. The head cavity or tail cavity of the wave acceleration structure 2 is set in the tail cavity 202 of the traveling wave acceleration structure in this embodiment.

The traveling wave acceleration structure 2 is a return-wave traveling wave acceleration structure 2, which is provided with an arc-shaped coupling hole 4, and the working mode is 2π/3 mode or 4π/5 mode. A transmission waveguide is connected between the head cavity 201 of the structure, the end cavity 101 of the standing wave acceleration structure and the beam channel in the center of the head cavity 201 of the traveling wave acceleration structure are connected by a beam drift tube, and the power feeding port is set in the traveling wave acceleration structure The tail cavity 202 is connected to the input waveguide 5 at the power feeding port.

The transmission waveguide is a U-shaped structure, and the two ends are connected to the side of the standing wave acceleration structure tail cavity 101 and the traveling wave acceleration structure head cavity 201 respectively. The orientation of the transmission waveguide and the power feeding port is the same, that is, the transmission waveguide and the input waveguide 5 are in the same direction. orientation, the size of the entire accelerator can be reduced.

The coupling method in this embodiment is that the waveguide coupling structure 301 connects the standing wave and the traveling wave structure, and the waveguide coupling structure 301 adopts a U-shaped transmission waveguide in this embodiment.

The working mode of the standing wave acceleration cavity is π/2 mode or π mode, the working mode is determined by the design structure of the standing wave acceleration cavity, and other working modes can also be used as long as the structure is reasonable.

The inner diameter of the beam tube of the traveling wave acceleration structure 2 is larger than the inner diameter of the fast flow tube of the standing wave acceleration structure 1, so as to prevent electrons from being hindered inside the beam tube, and the beam tube needs to be designed as an integral structure, which is convenient for electrons in the beam current. Intra-tube exercise.

In this embodiment, the standing wave acceleration structure 1 is used to accelerate and constrain the electrons to prevent the electrons from spreading out. When the electrons reach the traveling wave acceleration structure 2, the speed of the electrons is close to the speed of light, and there is no need to constrain the electrons. The high acceleration performance of the wave accelerator accelerates electrons. Such a design does not require an external magnetic field to focus the electrons, which reduces the volume occupied by the focusing system and simplifies the structure of the accelerator.

Example 2:

A hybrid acceleration structure type electron linear accelerator, which includes two types of acceleration structures, namely, a standing wave acceleration structure 1 and a traveling wave acceleration structure 2. The standing wave acceleration structure 1 is connected to the front end of the traveling wave acceleration structure 2, and the standing wave acceleration structure 1 is connected to the front end of the traveling wave acceleration structure 2. There is a coupling structure between the tail cavity 101 of the accelerating structure and the first cavity 201 of the traveling wave accelerating structure. The power feeding port of the accelerating tube is set on the traveling wave accelerating structure 1, and the power feeding port of the accelerating tube is in the first cavity of the traveling wave accelerating structure 2. Or the tail cavity, which is set in the tail cavity 202 of the traveling wave acceleration structure in this embodiment.

The traveling-wave accelerating structure 2 is a return-wave traveling-wave accelerating structure 2, which is provided with an arc-shaped coupling hole 4, the working mode is 2π/3 mode or 4π/5 mode, and the first cavity 201 of the traveling wave accelerating structure is directly connected to the standing wave. The tail cavity 101 of the accelerating structure shares a cavity wall, which is called the common cavity wall 7, that is, the traveling wave accelerating structure 2 and the standing wave accelerating structure 1 are actually a whole, and the first cavity 201 of the traveling wave accelerating structure is directly connected to the standing wave accelerating structure. There is only one cavity wall between the structural tail cavity 101, and such a design can make the whole of the accelerator more compact and reduce the volume of the accelerator. The absorbing load 6 is connected to the head cavity 201 of the traveling wave acceleration structure, and the power feeding port is arranged in the tail cavity 202 of the traveling wave acceleration structure. The absorbing load 6 absorbs part of the residual power of the traveling wave acceleration section; the waveguide connected to the tail cavity of the traveling wave acceleration section is the input waveguide 5, which is the port for power feeding. A part of the remaining power of the light-speed cavity array in this embodiment is used for establishing the electromagnetic field of the standing wave cavity array in the focusing section, and the other part is absorbed by the absorbing load 6 .

The absorption load 6 is located on the same side of the cavity array as the power feeding port, which can reduce the size of the entire accelerator.

In this embodiment, the coupling structure between the end cavity 101 of the standing wave acceleration structure and the head cavity 201 of the traveling wave acceleration structure is the magnetic coupling structure 302. Of course, side coupling or electrical coupling can also be used, as long as it is a reasonable coupling structure, it can be used. , as long as it can meet the needs of use.

The working mode of the standing wave acceleration cavity is π/2 mode or π mode, the working mode is determined by the design structure of the standing wave acceleration cavity, and other working modes can also be used as long as the structure is reasonable.

The inner diameter of the beam tube of the traveling wave acceleration structure 2 is larger than the inner diameter of the fast flow tube of the standing wave acceleration structure 1, so as to prevent electrons from being hindered inside the beam tube, and the beam tube needs to be designed as an integral structure, which is convenient for electrons in the beam current. Intra-tube exercise.

In this embodiment, the standing wave acceleration structure 1 is used to accelerate and constrain the electrons to prevent the electrons from spreading out. When the electrons reach the traveling wave acceleration structure 2, the speed of the electrons is close to the speed of light, and there is no need to constrain the electrons. The high acceleration performance brought about by the high-efficiency characteristics of the wave accelerator accelerates electrons. Such a design does not require an external magnetic field to focus the electrons, which reduces the volume occupied by the focusing system and simplifies the structure of the accelerator.

Example 3:

A hybrid acceleration structure type electron linear accelerator, which includes two types of acceleration structures, namely, a standing wave acceleration structure 1 and a traveling wave acceleration structure 2. The standing wave acceleration structure 1 is connected to the front end of the traveling wave acceleration structure 2, and the standing wave acceleration structure 1 is connected to the front end of the traveling wave acceleration structure 2. There is a coupling structure between the tail cavity 101 of the accelerating structure and the first cavity 201 of the traveling wave accelerating structure. The power feeding port of the accelerating tube is set on the traveling wave accelerating structure 1, and the power feeding port of the accelerating tube is in the first cavity of the traveling wave accelerating structure 2. Or the tail cavity, which is set in the head cavity 201 of the traveling wave acceleration structure in this embodiment.

The traveling-wave accelerating structure 2 is a disk-load traveling-wave accelerating structure 2 with a positive group velocity, and the working mode is 2π/3 mode. The cavity wall is called the shared cavity wall 7, that is, the traveling wave acceleration structure 2 and the standing wave acceleration structure 1 are actually a whole, and the first cavity 201 of the traveling wave acceleration structure is directly connected to the standing wave acceleration structure tail cavity 101 and there is only one cavity. Bi, such a design can make the whole of the accelerator more compact and reduce the volume of the accelerator. The absorbing load 6 is connected to the tail cavity 202 of the traveling wave acceleration structure, and the power feeding port is set in the head cavity 201 of the traveling wave acceleration structure. In this embodiment, a part of the input power is directly transmitted to the standing wave cavity column through the coupling structure between the beamforming section and the speed of light section for field focusing, and the other part is transmitted downstream of the beam to the light speed cavity column until it reaches the end The cavity will output the remaining power and be absorbed by the absorbing load 6 .

The absorption load 6 is located on the same side of the cavity array as the power feeding port, which can reduce the size of the entire accelerator.

In this embodiment, the coupling structure between the end cavity 101 of the standing wave acceleration structure and the head cavity 201 of the traveling wave acceleration structure is the electrical coupling structure 303. Of course, side coupling or magnetic coupling can also be used, as long as it is a reasonable coupling structure, it can be used. , as long as it can meet the needs of use.

The working mode of the standing wave acceleration cavity is π/2 mode or π mode, the working mode is determined by the design structure of the standing wave acceleration cavity, and other working modes can also be used as long as the structure is reasonable.

The inner diameter of the beam tube of the traveling wave acceleration structure 2 is larger than the inner diameter of the fast flow tube of the standing wave acceleration structure 1, so as to prevent electrons from being hindered inside the beam tube, and the beam tube needs to be designed as an integral structure, which is convenient for electrons in the beam current. Intra-tube exercise.

In this embodiment, the standing wave acceleration structure 1 is used to accelerate and constrain the electrons to prevent the electrons from spreading out. When the electrons reach the traveling wave acceleration structure 2, the speed of the electrons is close to the speed of light, and there is no need to constrain the electrons. The high acceleration performance brought about by the high-efficiency characteristics of the wave accelerator accelerates electrons. Such a design does not require an external magnetic field to focus the electrons, which reduces the volume occupied by the focusing system and simplifies the structure of the accelerator.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", " rear, left, right, vertical, horizontal, top, bottom, inside, outside, clockwise, counterclockwise, etc., or The positional relationship is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, Therefore, it should not be construed as a limitation of the present invention.

In the present invention, unless otherwise expressly specified and limited, the terms "installed", "connected", "connected", "fixed" and other terms should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection , or integrated; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of the two elements or the interaction relationship between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

In the present invention, unless otherwise expressly specified and limited, a first feature "on" or "under" a second feature may include the first and second features in direct contact, or may include the first and second features Not directly but through additional features between them. Also, the first feature being "above", "over" and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is level higher than the second feature. The first feature is "below", "below" and "below" the second feature includes that the first feature is directly and diagonally below the second feature, or simply means that the first feature is level below the second feature.

The above are only the preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be regarded as limitations of the present invention, and the protection scope of the present invention should be based on the scope defined by the claims. For those skilled in the art, without departing from the spirit and scope of the present invention, several improvements and modifications can also be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims (10)

1. A mixed acceleration structure type electronic linear accelerator is characterized by comprising two types of acceleration structures, namely a standing wave acceleration structure and a traveling wave acceleration structure, wherein the standing wave acceleration structure is connected to the front end of the traveling wave acceleration structure, a coupling structure is arranged between a tail cavity of the standing wave acceleration structure and a head cavity of the traveling wave acceleration structure, and a power feed-in port of an acceleration tube is arranged on the traveling wave acceleration structure.

2. The hybrid acceleration structure type electron linear accelerator of claim 1, wherein the traveling wave acceleration structure is a backward wave type traveling wave acceleration structure, the operation mode is 2 pi/3 mode or 4 pi/5 mode, a transmission waveguide is connected between the tail cavity of the standing wave acceleration structure and the head cavity of the traveling wave acceleration structure, a beam drift tube is used for connecting the tail cavity of the standing wave acceleration structure and the beam channel at the center of the head cavity of the traveling wave acceleration structure, the power feed port is arranged at the tail cavity of the traveling wave acceleration structure, and the standing wave acceleration structure and the traveling wave acceleration structure are connected by a waveguide coupling structure.

3. The hybrid accelerating structure type electron linear accelerator of claim 2, wherein the transmission waveguide is a U-shaped structure, and both ends of the transmission waveguide are respectively connected to the side surfaces of the tail cavity of the standing wave accelerating structure and the head cavity of the traveling wave accelerating structure, and are oriented in the same direction as the power feed port.

4. The hybrid acceleration structure type electron linear accelerator of claim 1, wherein the traveling wave acceleration structure is a backward traveling wave acceleration structure, the operation mode of the traveling wave acceleration structure is 2 pi/3 mode or 4 pi/5 mode, the first cavity of the traveling wave acceleration structure is directly connected to the tail cavity of the standing wave acceleration structure and shares a cavity wall, the first cavity of the traveling wave acceleration structure is connected to an absorption load, and the power feed port is disposed at the tail cavity of the traveling wave acceleration structure.

5. The electron linear accelerator of claim 1, wherein the traveling wave accelerating structure is a forward group velocity disk-loaded traveling wave accelerating structure, the operation mode is 2 pi/3 mode, the first cavity of the traveling wave accelerating structure is directly connected to the tail cavity of the standing wave accelerating structure and shares a cavity wall, the tail cavity of the traveling wave accelerating structure is connected to the absorption load, and the power feed port is disposed in the first cavity of the traveling wave accelerating structure.

6. A hybrid accelerating structure type electron linear accelerator as defined in claim 4 or 5, wherein the absorbing load and the power feed port are located on the same side of the cavity array.

7. The electron linear accelerator according to any one of claims 1, 4 or 5, wherein the coupling structure is an edge coupling or an electric coupling or a magnetic coupling.

8. The hybrid accelerating structure type electron linear accelerator as claimed in any one of claims 1, 2, 4 and 5, wherein the operating mode of the standing wave accelerating cavity is pi/2 mode or pi mode.

9. The electron linear accelerator according to any one of claims 1, 2, 4 and 5, wherein the inner diameter of the beam flow tube of the traveling wave acceleration structure is larger than the inner diameter of the fast flow tube of the standing wave acceleration structure.

10. A hybrid accelerating structure type electron linear accelerator as defined in any one of claims 1, 2, 4 and 5 wherein the input waveguide is connected to the power feed port.

Images